The increase in the number of species-group/complexes is mostly due to
the discoveries of new species/forms that are related to species not previously assignable to already
existing groups or complexes. Some of these groupings are speculative, due to the lack of precise
distribution data as well as little to no meristic or genetic data for the scientifically undescribed
species.
Identification of the species-groups listed here is based primarily on
the black markings shared by all of the species within an individual species-group. Other features,
such as the shape of the body and the dorsal and caudal fins of males, are also useful but aren't as
reliable. These are all readily visible on live fish and make them more useful for hobbyists.
Other features, such as the skeletal and pharyngeal teeth structure, are equally valuable but are not
readily seen on living fish. Breeding behavior and aggressive display behavior are generally similar
within a species-group. The number of sensory pores found on the head is another feature that is very
valuable. These pores can be used to separate the genus into three major blocks. I consider those
species-groups with a full compliment of 4 infraorbital and 5 dental pores to be
the more primitive or "ancestral" groups. Those that have reduced infraorbital and dental pore counts
are considered members of more "advanced" species-groups. The "advanced" species-groups can be further
subdivided by reductions in dental pores. Pore reduction, however, might also be seen in dwarf species
where the reduced number of pores is caused by the small size of the fish. These pores usually cannot
be seen without magnification, thus this feature is difficult to use on live specimens.
Cephalic Pores
dp = dental pores (two pores on the other side of the head are not visible from this
side);
ip = infraorbital pores; aap = anguloarticular pores.
The shape of the fins and body can also be used to separate ancestral
from advanced species, but are not totally reliable. Apistogramma males with tails that are
round to oval, truncate (squared-off), or exhibit slight extensions at the top and bottom of the tail
(double tipped) are often ancestral species. Those with caudal fin extensions placed closer to the
middle of the fin's edge (lyrate) or spade-shaped are always members of advanced species-groups.
Likewise, Apistogramma males with even dorsal fins that show very little or no serrations and
possess at best minor dorsal fin extension are typically ancestral forms. Those with "fancy" dorsal
fins, that have extremely long anterior dorsal spines and lappets, or sail-like fins, are almost always
advanced species. With regard to body shape, ancestral forms tend to be more deep-bodied and more
laterally compressed. Advanced forms commonly are elongate and less compressed. Pronounced sexual
dimorphism is more commonly seen in advanced species, as is the tendency toward polygamy.
One important thing to remember, however, is that while ancestral species cannot exhibit advanced
characteristics, advanced species can - and frequently do - exhibit "retrograde" ancestral features.
DESCRIPTION
To properly recognize the important diagnostic features used for the
identification of Apistogramma species, it is important to know how to locate the dark markings
and other diagnostic features on these fish. The most important dark markings are shown on the
following figures:
Primary Dark Markings
1. Preorbital (Nose) Stripe, which extends from the eye to the tip of the snout.
2. Supraorbital (Forehead) Stripe, which extends from the eye to the back of the
forehead.
3. Suborbital (Cheek) Stripe, which extends downward from the eye, usually to the
edge of the gill cover.
4. Postorbital Stripe, a narrow extension of the lateral band from the
back of the eye to the back of the gill cover.
5. Vertical Bars, seven (rarely eight or six) evenly spaced bars that extend from
the dorsal edge to the ventral edge of the body. These bars vary in width and intensity depending on
the species and the mood of the individual fish.
6. Lateral Band, a broad horizontal band that extends along the mid-line of the flanks,
from the posterior edge of the gill cover to the base of the caudal fin. In some species it extends
into the caudal fin. The lateral band can break up into a row of spots on many apisto species. These
spots are typically equal in width or slightly wider than the lateral band. The number of spots,
depending on species and mood, can vary from seven (rarely eight) to zero; five to seven is more
typical.
7. Caudal Spot, a blotch on the base of the caudal peduncle posterior of Bar 7. This
spot can vary in size and shape depending on the species. On some species it is part of the lateral
band that extends into the caudal fin.
8. Lateral Spot, develops at the intersection of Bar 3 and the lateral band. When in
a series of flank spots, it is typically the largest. Certain groups of species don’t show a lateral
spot.
Secondary Dark Markings
9. Flank Patch, a blotch seen on Bar 3 that extends well above the lateral band. It is
much taller and wider than a lateral spot.
10. Abdominal Stripes, form as dark horizontal stripes on the abdomen below the lateral
band. These stripes can be continuous and even, wavy, or even as a series of closely spaced blotches.
11. Abdominal Streaks, form slightly diagonal vertical stripes on the
abdomen below the lateral band. These are usually formed by dark
pigment on the front or rear edge of scales, so they are not typically
continuous.
12. Abdominal Bands, develop from part of the vertical bars, but appear
only below the lateral band.
13. Anal Blotch, dark pigment visible only around anus.
14. Ventral Stripe, a dark stripe that extends along the ventral edge of the head
and/or body. It is variable in length, where it can appear anywhere between the lower lip and the anus.
15. Dorsal Spots, form from darkening of the dorsal part of the
vertical bars. The dorsal spots can spread into the base of the dorsal fin on some species.
16. Pectoral Blotch, forms from dark pigmentation around the insertion of the pectoral
fins.
17. Postorbital Blotch, forms from darkening of part of Bar 1, immediately behind the
posterior edge of the gill cover.
18. Caudal Patch, a dark patch on the caudal peduncle formed from part of Bar 7 and
the caudal spot.
19. Caudal Fin Markings, patterns of dark markings on the caudal fin. Caudal fins can
be hyaline/clear, have a series of rows of spots and/or horizontal stripes, or rings of color around
the outer margin.
Primarily using dark markings and assisted by cephalic pores, finnage,
body shape, and behavioral characteristics, it's possible to describe the species-groups. As in my
previous articles on the subject, this caveat applies: Since this isn't a scientific paper and I don't
have a "professional reputation" to protect, I'm allowing myself more license in suggesting
relationships than would a professional taxonomist!
Apistogramma-regani-Lineage
All members of the A.-regani-lineage are distinguished by having
a complete set of 4 infraorbital and 5 dental pores. In addition, members of the A.-regani-
lineage do not show a lateral spot on vertical Bar 3. Most species show a lateral band that breaks
into flank spots, but none shows a more distinct lateral spot. Most show a caudal spot clearly
separated from the lateral band. The caudal fins of males are typically round to squared off, but
some have short extensions at the top and bottom of a squared off fin. The A.-regani-lineage
includes the A.-regani-, A.-alacrina-, and A.-macmasteri-groups. The unassigned
species Apistogramma borellii and Apistogrammoides pucallpaensis are also considered
part of the A.-regani-lineage.
Apistogramma-regani-Group
Species of the A.-regani-group exhibit many plesiomorphic
(primitive) features. Most show very little sexual dimorphism and tend to be for the most part
casually polygamous. This means that the male does not expend extraordinary time & energy acquiring
and maintaining a large territory with several female territories in it. If his territory has several
females in it, however, he will breed with them all.
Morphologically, A.-regani-group species are characterized by
their relatively deep bodies, low and even dorsal fins (1),
typically round caudal fins (2), often showing vertical flank
bars (3), and lack a lateral spot on the lateral
band (4). As would be expected, the A.-regani-group
represents an ancestral group with a complete set of four infraorbital pores below each eye and five
dental pores along the lower jaw.
The Apistogramma-regani-group is the most widely distributed of
the Apistogramma species-groups. They can be found in most tributaries of the Amazon Basin. They
are also found in coastal streams entering the Atlantic Ocean from eastern Venezuela to the Rio
Parnaiba of eastern Brazil. They also can be found in the Paraguay-Paraná Basin of southeastern
Brazil to northeastern Argentina. There are presently over 30 scientifically described and more than
70 undescribed species within the group, including Apistogrammoides pucallpaensis. With so many
species it's not surprising that the Apistogramma-regani-group has been subdivided into ten
complexes and even includes species that are not assignable to any of the complexes.
Apistogramma-kullanderi-Complex
The A.-kullanderi-complex is composed of moderately large to very
large (up to 5 in./12.5 cm TL) species closely related to species of the A.-sp.-"Xingu"-complex.
They share the same robust, moderately deep body seen on populations of A. sp. "Xingu".
The most conspicuous differences between species of the A.-kullanderi-complex and the
A.-sp.-"Xingu"-complex are seen in the dark markings on the females. The vertical
bars (1) show extremely irregular borders, something extremely
rare in other Apistogramma species. Females also show a large black gullar
area (2) extending from the lower lip to the vent.
Presently all known members of the A.-kullanderi-complex occur in
the upper Rio Xingu except A. sp. "Peixoto", which occurs in nearby tributaries of the upper
Rio Tapajós. There are presently three scientifically described and one undescribed species in the
complex. I consider species of the A.-kullanderi-complex to be closest to the ancestral form of the genus
Apistogramma. They show many pleisiomorphic features also seen in the rhabdotus-group of the genus
Gymnogeophagus, which Kullander (1998) considers phylogenetically a sibling/sister-genus of Apistogramma.
Among these are size, sexual dimorphism, and the bar pattern on females. Their ranges are separated by the Brazilian Highlands.
The A.-kullanderi-complex occurs along the northern periphery of this highland, while the rhabdotus-group is
found on the southern side of the highland.
Apistogramma-sp.-"Xingu"-Complex
The species of the A.-sp.-"Xingu"-complex are small to moderate in size
(<2¾ in./ 7 cm TL). They show a mix of features seen on both the A.-caetei-
and A.-regani-complexes. They have slender to moderately deep bodies and
males have low to moderately high dorsal fins with even spines. The deeper
bodied species have a moderately broad lateral band; the slender bodied
species have a narrower band. Unlike on A.-caetei-complex species, the
lateral band has even top and bottom borders (1) and it becomes
gradually broader toward the posterior (2). It ends in front of a
caudal spot, as on A.-regani-complex species, but the area between the end
of the band and the caudal spot (3) is not as bright as seen on the
A.-regani-complex species. The caudal spot on A.-sp.-"Xingu"-complex
species tends to be small and either round or square (4). The caudal spot on
A.-regani-complex species tends to be larger and more oval or vertically
oriented. The caudal fin is round, usually with rows of fine stripes.
There are five, possibly more, undescribed species in the
A.-sp.-"Xingu"-complex.
Most species of the complex are found in the middle to lower Rio Xingu.
One species occurs in the lower Rio Tapajós. The species A. sp. "Itaparaná", reported to be
from the Rio Purus, appears to be a population of A. sp. "Chao" from the Rio Xingu and most
likely doesn’t actually occur in the Rio Purus.
There are no scientifically described species within the complex, which presently includes at least
seven undescribed species.
Apistogramma-caetei-Complex
The A.-caetei-complex is an assemblage of medium sized species (<3
in./7.5 cm) with a relatively robust body. They are characterized by
having abdominal streaks (1) that form thin diagonal bars below a
narrow zigzag lateral band (2) and a pattern of vertical rows of spots
over the entire caudal fin (3) on males. The lateral band ends in Bar 7
in front of a caudal spot. Part of Bar 7 is darker just below the
lateral band. This makes the lateral band appear to have a downward,
right angle break (4) just in front of the caudal spot. Presently there
is only one, but possibly three other scientifically described and at least
six undescribed species that can be assigned to the complex.
Species in the A.-caetei-complex are known to occur in Atlantic coastal
streams from the Rio Parnaiba, northward to Ilha de Marajó at the mouth
of the Amazon, and into to Brazilian state of Amapá near Macapá.
Species are also found in tributaries of the Rio Tocantins system of
eastern Brazil. Another is questionably believed to originate from the
upper Rio Paraguay.
Apistogramma-resticulosa-Complex
The A.-resticulosa-complex is composed of a group of relatively small
species (<2¾ in./7 cm). In addition to the standard A.-regani-group
features, these species exhibit a narrow zigzag lateral band (1), a
series of faint, poorly defined, abdominal streaks in the form of
vertical dashes below the lateral band (2). These characteristics are
similar to features seen on members of the A.-caetei-complex. The body,
however, is not as robust as that of A.-caetei-complex species and the
lateral band doesn’t show the downward break at Bar 7. There are faint
stripes toward the center or only on the posterior part of the caudal
fin (3) and the body usually shows a blue sheen on males.
Presently there are two, possibly four, scientifically described species and another dozen or
more undescribed species/forms within the complex.
The species of the A.-resticulosa-complex are almost all found south of the main channel of the Amazon. Their distribution
includes the Bolivian Amazon and extreme southeastern Peru and southwestern Brazil, which are extensions of the Bolivian Amazon
drainage. From this locus, they are distributed down the Rio Madeira, eastward into the lower parts of the southern tributaries of
the Amazon, and down to the Ilha de Marajó at the mouth of the Amazon.
Apistogramma-commbrae-Complex
The species of the A.-commbrae-complex appear to be offshoots of the
A.-resticulosa-complex. Members of both complexes show many similarities.
The A.-commbrae-complex is comprised of a group of mostly small species
(<2¾ in./7 cm). Members show most of the characteristics found on all species of the
A.-resticulosa-complex, although the abdominal streaks seen on the A.-resticulosa-complex
are modified into horizontal abdominal stripes (1) on some species
in the A.-commbrae-complex.
One feature that separates the species of the A.-commbrae-complex from those of the
A.-resticulosa-complex is a distinctive caudal blotch (2).
This blotch is formed from the caudal spot that has merged with a highly pigmented part of Bar 7.
The A.-commbrae-complex includes four scientifically described species. Some geographic populations
of these species possibly are separate undescribed species.
All are found in the Bolivian Amazon and Rio Paraguay system.
Apistogrammoides-Complex
The genus Apistogrammoides, which contains only one species –
Apistogrammoides pucallpaensis, is genetically part of the
A.-regani-lineage and probably more closely related to a deep-bodied
member of the A.-commbra-complex, like A. linkei. Therefore, it
can be considered a complex within the A.-regani-group. It differs from
other A.-regani-group species by not showing a distinct caudal spot.
Instead, Apistogrammoides shows a vertical band at the base of the
caudal fin that joins to a narrow more even edged lateral band, where
they form a "T" shaped pattern (1). The anal fin has 7-8
anal spines (2) – twice the number seen on species of
Apistogramma.
Apistogrammoides pucallpaensis is distributed throughout the Peruvian
Amazon – from tributaries of the middle Río Ucayali to the Colombian
Amazon around Leticia.
Apistogramma-borellii-Complex
Apistogramma borellii is a non-allied species from the Río Paraguay
drainage. It is characterized by its small size (<2¼ in/6 cm), deep
and laterally compressed body, high sail-like dorsal fin (1), and round
to very slightly spade-shape tail (2). A zigzag lateral band is usually
visible only on the posterior half of the body (3). Flank bars are only
visible when under stress. A bright blue colored body is typical of
males. The infraorbital pores in A. borellii are reduced to three, an
advanced species characteristic. On the other hand, the anguloarticular
canals are usually missing entirely, something found only in one other
Apistogramma species, A. trifasciata, also found in the Río Paraguay.
Perhaps reduction in sensory pores may be related to subtle differences
found in the environment of the Río Paraguay, although it may also be a
chance mutation like that which occurred in the A.-pertensis-group. In
many respects A. borellii appears to be a deeper bodied, higher finned,
offshoot of the A.-macmasteri-group.
Only one other form might be a member of this group. This is
Apistogramma sp. "Río Paraguay III" (Mayland & Bork, 1997a, b). It
looks much like a slender, low dorsal finned A. borellii. It was found
only once and nothing is known of its natural habitat. Apistogramma
sp. "Río Paraguay III" was found in a shipment of A. borellii from the upper
Río Paraguay. There is a good possibility that it is only an aberrant
A. borellii.
Apistogramma borellii is distributed throughout much of the Río
Paraguay/Paraná drainage, from the southern Mato Grosso of southern
Brazil to the city of Corrientes in northern Argentina. It also
occurs in tributaries of the Río Uruguay in Uruguay. It has the
southern-most distribution of any species of Apistogramma, extending
even into subtropical South America. As such it is more cold tolerant
than most Apistogramma species.
Apistogramma-regani-Complex
Species in the A.-regani-complex comprise an assemblage of mostly medium
sized (<3 in./7.5 cm), deep bodied and laterally compressed fish
characterized by seven conspicuous vertical bars running the entire
height of the body (1). These bars are chiefly visible on juveniles and
females. In addition, all species in the A.-regani-complex are
characterized by having a very pale zone that separates the lateral
band from the caudal spot (2).
There are at present five scientifically described and at least 11 undescribed species placed
within the complex.
Species of the A.-regani-complex are widely distributed throughout the
Amazon drainage. The locus of the complex appears to be centered in
streams along the middle and lower Amazon. Other species are also found
in the upper Purus, and Juruá drainages of southwestern Brazil, the
upper Negro of northern Brazil and southeastern Colombia, and in the lower Ucayali of Peru.
Species are also found in Atlantic coastal streams from north of the
Amazon to the Guyana/Venezuela border.
Apistogramma-sp.-"Winkelfleck/Angle-patch"-Complex
The species of the A.-sp.-"Winkelfleck"-complex show features
similar to those of the A.-regani- and A.-sp.-"Xingu"-complexes. These fish are
moderately large (<3 in./7.5 cm) and have a deep and highly laterally
compressed body. Males have low, even dorsal fins. The cross-striped caudal fin
is noticeably small in comparison to the size of the fish (1).
The most diagnostic characteristic is the pattern of its vertical bars that show
during aggressive display. The bars extend diagonally backwards on the
abdomen (2). Only two forms are presently known.
The A.-sp.-"Winkelfleck"-complex occurs in tributaries of the Río Nanay (Peru) and in
southern tributaries of the Amazon between the Río Orosa in Peru and Leticia, Colombia.
Apistogramma-eunotus-Complex
The species of the A.-eunotus-complex are all moderately
large (<3½ in/9 cm). Their deeper, laterally compressed bodies
(1) distinguish them from most members of the
A.-regani-complex. The species also show
greater sexual dimorphism than seen that in other A.-regani-group
complexes. The caudal fin shape is usually round but some species can
develop a truncate fin with no, one, or even two short caudal extensions.
All have a fairly broad lateral band, usually with even borders
(2), separated from a distinct caudal spot. The area
between the lateral band and caudal spot is not pale like that seen on regani-complex fish.
There are seven scientifically described species and at least another 30 undescribed forms in the
complex. This does not include two scientifically described and several undescribed species that
show attributes of both the A.-eunotus- and A.-regani-complexes.
All of the species within the A.-eunotus-complex occur in the Río Amazonas drainage of Peru
and Colombia, plus one in the neighboring Rio Jutai (Brazil) and Río Putumayo drainage in Colombia.
Based on secondary features, mostly dark markings, the A.-eunotus-complex can be split into
three subcomplexes.
Apistogramma-eunotus-Subcomplex
In addition to features seen on all species in the A.-eunotus-complex, the
species of the A.-eunotus-subcomplex are characterized by a comparatively
higher, even to slightly serrated, dorsal fin (1). Males commonly
possess round tails, colored orange in parts. Some species can develop
one or two caudal fin extensions. An orange spot at the insertion of
the pectoral fin is characteristic of this subcomplex (2). Many, but
not all species of the A.-eunotus-subcomplex develop one or more split
vertical bars on the posterior half of the flanks when in threat
display. These splits are formed from scales that become light colored
in the 5th, 6th and rarely 7th
vertical bars below the lateral band (3). Split vertical bars are not
unique to this A.-eunotus-subcomplex species. It is also seen on some
species of the A.-steindachneri- and A.-cacatuoides-groups as well
as a couple of other A.-regani-group species. On these species, however,
the split bars are more extensive, ranging from the 4thto the 7th
vertical bars.
There are two scientifically described and at least ten undescribed species/forms within the subcomplex.
The A.-eunotus-subcomplex is distributed exclusively in the Peruvian and Colombian Amazon and Rio Jutai
in western Brazil.
Apistogramma-cruzi-Subcomplex
The species of the A.-cruzi-subcomplex are similar to A.-eunotus-
subcomplex species. They, however, are distinguished by their lack of split vertical bars.
The dorsal fin on males is lower and rarely shows serrated spines (1).
The posterior tip of the soft dorsal fin is typically longer, too (2).
Males in many populations develop a more oval to truncate shaped caudal fin, often with two short caudal extensions.
All show well-developed abdominal stripes (3).
There presently are three scientifically described species and more than 15 undescribed species/forms in the subcomplex.
The A.-cruzi-subcomplex is distributed in tributaries of the extreme western Amazon system. Representative of the
subcomplex occur in the lower Río Ucayali in Peru, the Río Napo system of Peru and Ecuador, the Río Putumayo system in Peru
and Colombia, and Río Caquetá system in Colombia.
Apistogramma-ortegai-Subcomplex
Very few characteristics separate members of the A.-ortegai-subcomplex
from those of the A.-cruzi-subcomplex. They could easily be considered to be
just one subcomplex. They are identical in body shape and fin
development. Abdominal stripes in the A.-ortegai-subcomplex are usually
present, but not as prominent as on A.-cruzi-subcomplex species. Species
in the A.-ortegai-subcomplex are often more colorful. Species of the
A.-ortegai-subcomplex can be easily separated from those of the
A.-cruzi-subcomplex by one feature. The A.-ortegai-subcomplex
species develop a caudal blotch from the caudal spot and part of the 7th
vertical bar (1), similar to that of the A.-commbra-complex.
The A.-ortegai-subcomplex presently includes two scientifically described species and possibly as
many as five undescribed species.
Species of the A.-ortegai-subcomplex are known only from northern
tributaries of the Peruvian Amazon between the Río Napo and the Río Ampiyacu.
Apistogramma-alacrina-group
The species of A.-alacrina-group show features that indicate that they may
form a bridge between species of the A.-macmasteri-group and those of the
A.-eunotus-complex. Most are medium to moderately large in size (2¼ - 3½ in./6 - 8 cm TL).
Their fairly broad lateral band has two rows of alternating light and dark scales. The rows of dark scales
are offset so that they form a zipper-like band (1). This band is
more similar to the zigzag lateral band seen on members of the A.-macmasteri-group than the even
bordered lateral band of A.-eunotus-complex species. The tail of the male is round to very slightly
squared off. The dorsal fin is low and even (2) on males, unlike the
high and serrated dorsal seen on males of the A.-macmasteri-group. In this
respect, it is more similar to that of males of the A.-cruzi-subcomplex.
Females of the A.-alacrina-group exhibit the yellow with black checkered
brood pattern characteristic of both the A.-macmasteri-group and A.-cruzi
–subcomplex. Like females of the A.-cruzi-subcomplex, females of most A.-alacrina-group
species do not develop a black ventral stripe typical for females of the A.-macmasteri-group.
Instead, females develop only an anal blotch. A pectoral blotch is
sometimes part of the female’s brood dress. The males, like males of
A.-macmasteri-group species, are highly polygamous.
This is an ancestral species-group, with four infraorbital and five dental pores.
The A.-alacrina-group can be separated into 2 species-complexes based on differences in size,
finnage, and some dark markings.
There is one scientifically described species (A. alacrina) and possibly ten or more undescribed
species in the group.
The A.-alacrina-group is distributed in northeastern Ecuador and southeastern Colombia.
Species are found in tributaries of both the Orinoco and Amazon.
Apistogramma-alacrina-Complex
The species of the A.-alacrina-complex are distinguished from species of the A.-sp.-"Mitu"-complex
by having larger (2¾ – 3½ in./7 – 8 cm TL), more robust bodies (1).
Males are visibly larger than females. The soft parts of the dorsal and anal fins are more extended, the dorsal
extending almost to the posterior of the caudal fin (2).
Almost all females in brood dress show a prominent dark blotch below and often above the pectoral fin insertion
(3).
The A.-alacrina-complex has one scientifically described and at least eight undescribed species.
Species of the complex are distributed in upper tributaries of the Amazon and Orinoco rivers in northeastern
Ecuador and southeastern Colombia.
Apistogramma-sp.-"Mitu"-Complex
The A.-sp.-"Mitu"-complex species appear to represent forms in the A.-alacrina-group that have adapted to
habitats in streams with a higher rate of flow than those of the A.-alacrina-complex. They are distinguished
from A.-alacrina-complex species not only by their smaller size (2¼ - 2¾ in. / 6 - 7 cm TL)
but by their more slender body form (1) and slightly larger caudal fin
(2) in proportion to body depth. A.-sp.-"Mitu"-complex species also show less elongated
soft rays on the dorsal and anal fins (3). These features appear to be adaptations to waters
with a higher rate of flow.
Sexual dimorphism in body size and finnage is less conspicuous than that in A.-alacrina-complex species.
A.-sp.-"Mitu"-complex species also show some differences in some of their dark markings. Unlike almost
all species of the A.-alacrina-complex, the species of the A.-sp.-"Mitu"-complex do not show a lower pectoral
spot and the upper one is very small when visible and does not extend above the pectoral
insertion (4), which it does on many A.-alacrina-complex species. The
lateral band, when visually continuous, often appears narrower between the last two bars on the caudal peduncle or
even shows a small gap at this position. When the lateral band appears as a row of spots,
this gap is often noticeably larger than the others (5).
There are at least 2, possibly more, species in the A.-sp.-"Mitu"-complex.
All are found in the middle and upper Río Vaupés and the Río Inirida systems of Colombia
Apistogramma-macmasteri-Group
The A.-macmasteri-group is closely related to the A.-regani-group.
It replaces the A.-regani-group in the Orinoco Basin. It is characterized by medium to moderately
large (2¾ – 3¼ in. / 7 – 8 cm TL), robust-bodied, sexually dimorphic species. Males have moderately to highly
extended, serrated, dorsal fin lappets (1). Caudal fins are round to
truncate with rare double tipped extensions. The lateral band typically forms a zigzag or ladder like
pattern or is broken into a series of spots (2). Dorsal spots are
usually visible along the insertion of the dorsal fin (3). Brooding
females exhibit an intense golden yellow body with a checkerboard pattern of black dorsal and lateral spots.
Most brooding females have a ventral stripe that extends somewhere between the chin to the vent,
or at least a dark spot at the insertion of the ventral fins.
All species in the A.-macmasteri-group have the ancestral four infraorbital and five dental
pores.
Presently there are ten scientifically described and many more undescribed species in the group. Many of the forms
may be geographic color variants but they also include some that are distinct species. More distribution data and
taxonomic/genetic studies are needed to clarify this question.
The species of the A.-macmasteri-group are found, with one exception, exclusively within the drainage of the
Río Orinoco. They are distributed from its headwaters in the foothills of Andes, in the Guiana Highlands in Colombia
and Venezuela, and all the way to the delta of the Río Orinoco on the Caribean coast of Venezuela.
The species of the A.-macmasteri-group can be divided into two complexes, based on the design of the lateral band
and other color markings. The A.-macmasteri-complex can be further divided into two subcomplexes based mostly on
body shape and dark markings.
Apistogramma-hongsloi-Complex
Males of the A.-hongsloi-complex can be recognized by a ladder/lattice-like lateral band
(1), a broad horizontal band, either
red or black, on the ventral part of the flanks along the insertion of
the anal fin (2), and usually a bright red patch that hides the caudal
spot (3). The lateral band is typically very broad
with lighter centers and dark edges on the scales. This forms the ladder-like pattern. This pattern is more
pronounced in the areas between the vertical bars. Wild forms of the A.-hongsloi-complex all show
a round caudal fin.
At present there are two scientifically described and at least four undescribed species within the the
A.-hongsloi-complex.
All known forms in the complex, except for one possible form, occur in the lower parts of Orinoco tributaries in
Colombia and Venezuela. The lone one, occurs in the middle Río Vaupés, a Colombian tributary of the Rio Negro/Amazon system.
They are found together with A.-macmasteri-complex species only in the Río Caura, Río Vichada and Río Guarrojo.
Apistogramma-macmasteri-Complex
In contrast to the A.-hongsloi-complex, species of the A.-macmasteri-complex develop a zigzag
lateral band (1). With rare exceptions, brooding females show no ventral stripe.
Males show an upper and lower red and/or black caudal fin borders (2). The
tail can be round to squared-off/truncate, some with one or two short extensions.
The A.-macmasteri-complex is found in tributaries of the Orinoco above
areas that contain A.-hongsloi-complex forms. Exceptions are A. guttata
from the delta of the Orinoco, and A. pedunculata from the Río Caura.
The A.-macmasteri-complex can be split into two subcomplexes based mostly on body shape and
dark marking around the head.
Apistogramma-macmasteri-Subcomplex
The A.-macmasteri-subcomplex is composed of species that tend to differ from species of the A.-hoignei-subcomplex
by exhibiting a slightly more slender or elongate body shape (1), mostly due to
having a slightly longer and narrower caudal peduncle. The caudal fin of males is round in younger specimens but it commonly
develops a squared off or double-tipped posterior margin in more mature specimens (2).
The top and bottom edges of the caudal fin are commonly bordered in red (3). In some
wild forms and many domestic strains most of the caudal fin can be red or orange. The head shows fewer and paler dark spots
compared to forms of the A.-hoignei-subcomplex (4). Brooding females commonly
exhibit a chest blotch (5), but with few exceptions show no markings on throat and chin.
At present there are two described species, possibly three if one includes A. guttata, and possibly 20 or more
undescribed forms in the A.-macmasteri-subcomplex.
They are primarily distributed in the upper reaches of tributaries of the Río Orinoco in Colombia.
Apistogramma-hoignei-Subcomplex
The A.-hoignei-subcomplex is composed of species that tend to differ from species of the
A.-macmasteri-subcomplex by exhibiting a slightly deeper body shape, mostly due to appearing to have
a slightly shorter and deeper caudal peduncle (1). Fin shape is similar
to that of species of the A.-macmasteri-subcomplex, but they often show a black edge at the top and bottom of the
caudal fin that is bordered interiorly by red (2). The head area shows more,
larger and usually darker spots compared to forms of the A.-macmasteri-subcomplex
(3). The males commonly show metallic bluish/greenish lips
(4) and sometimes a metallic bluish/greenish area that covers the posterior edge
of the caudal spot (5). Males also commonly exhibit a row of dark spots in the upper
third of each hard dorsal spine lappet that is bordered above by light metallic tips (6).
These color patterns are rarely seen in A.-macmasteri-subcomplex males. Brooding females usually show distinct
black markings on throat and chin (7).
Presently there are at least five described species, possibly six if one includes A. guttata, and at least four
undescribed forms in the A.-hoignei-subcomplex. They are primarily distributed in the lower reaches of tributaries
of the Río Orinoco, closer to its main channel, in Colombia and Venezuela.
Apistogramma-pertensis-Lineage
Based on the genetic studies of Miller & Schliewen (2005), the
A.-pertensis-lineage is composed of the A.-steindachneri-group and its
sister taxon, A. wapisana, plus the A.-pertensis-group and its sister
taxa, the A.-iniridae-group. Unlike the A.-regani-lineage, species in
the A.-pertensis-lineage show a pronounced lateral spot. A similar lateral spot
is seen on most forms in “advanced” species-groups, but these species typically show a
reduction of cephalic pores. Species in the A.-pertensis-lineage, however, – with
the exception of A. wapisana and forms in the A.-iniridae-group – almost
always show a complete series of cephalic pores like species in the A.-regani-lineage.
Apistogramma wapisana
Apistogramma wapisana is an unusually tiny species (< 1½ in./3.5 cm)
showing a mix of features exhibited by the A.-steindachneri- and
A.-pertensis-groups. Like members of the A.-steindachneri-group, it
shows a large flank patch (1) that extends above a narrow lateral
band (2). The body shape is elongate and slightly fusiform, like
that of members of the A.-pertensis-group, but the dorsal fin is very low (3).
It shows a reduced number of infraorbital pores, but this is more likely due to
its tiny size than being an advanced form.
It is notable for being one the few Apistogramma species having
reversed sexual dimorphism, where the males are slightly smaller than the
females. Also unusual is its breeding behavior in which, unlike in
most Apistogramma species, the male A. wapisana initiates courtship.
The distribution of Apistogramma wapisana occurs in the Rio Branco and
middle Rio Negro. Its distribution, like its physical features, are
intermediate between the primary loci of the A.-steindachneri-group
(Guyana, Surinam, Rio Negro) and the A.-pertensis-group (middle to lower
Amazon).
Apistogramma-steindachneri-Group
The A.-steindachneri-group is comprised of medium to large species (< 3¾ in/9 cm)
with moderately deep, laterally compressed, bodies that
show minor sexual dimorphism. Males are casually polygamous. If there
are several females and only one male, the male will spawn with each
female. If, however, there are two fairly equal males and if there are
at least two females and enough room for each male to hold a territory,
each male will form part of a breeding pair. There usually won't be a
dominant male servicing all of the females. Males are noticeably larger
than their female counterpart. They can have moderately extended dorsal
fin lappets that can be even to very slightly serrated (1). The males'
caudal fins can be round, truncate, or double-tipped. Vertical bars and
the lateral band are usually visible only on frightened or stressed
individuals. During aggressive display, some of the posterior vertical bars appear as
split narrow vertical bands. A large flank patch (2) situated
on or immediately above the narrow, rarely visible, lateral band (3) is
characteristic of A.-steindachneri-group species. This
group is "ancestral", possessing four infraorbital and five dental
pores.
There are presently three scientifically described and at least
two, possibly four undescribed species in the A.-steindachneri-group.
The A.-steindachneri-group shows a continuous distribution from Guyana and
Suriname down the Rio Branco and south into the mouth of the Rio Negro.
Species are also found in the Rio Tefé and Rio Madeira systems.
Apistogramma-pertensis-Group
The Apistogramma-pertensis-group is comprised of a series of tiny to medium-sized
(1½ - 3.5 in./4 – 7.5 cm), elongate, slightly fusiform, species that generally
lack much pigmentation on the anterior dorsal fin rays (1). In males,
most or all of the dorsal fin lappets commonly extend well above the
fin rays and are fused together into a sail-like filament (2). The
lateral band is narrow (3) and ends in front of a caudal spot. Male
caudal fins are round, lyrate, spade or even three-lobed
shaped and covered by rows of spots. Vertical bars are only visible on
stressed fish. Other than the height of the dorsal fin on males there is little sexual dimorphism and
for the most part the species are preferentially monogamous.
There are six scientifically described and at least six undescribed species in the
A.-pertensis-group, which is split into two complexes.
Distribution of the A.-pertensis-group includes tributaries of the
Amazon between the Rio Tapajós (lower Amazon) and the Rio Tefé (middle
Amazon/Solimðes), the entire Rio Negro drainage, and adjoining areas of
the upper and middle Río Orinoco.
Apistogramma-pertensis-Complex
Besides the characteristics found on all members of the
A.-pertensis-group, males of the Apistogramma-pertensis-complex
species all have round to modified oval-shaped tails. Apistogramma sp.
"Erdfresser/Earth-eater" is atypical in that it has a lyrate or three-lobed tail and
A. sp. "Schwanzzipfel/Tail-point" has a lyrate tale that eventually becomes
spade shaped. A.-pertensis-complex species typically show no black
pigmentation on the flanks except for the lateral band and lateral
spot (1). The dorsal fin usually has the first 3 spines separated from a
sail like fin (2). Most scientifically described species have the
ancestral four infraorbital pores and five dental pores, although some species show only 3 infraorbital pores.
This species-complex occurs in the Orinoco and Rio Negro drainage, with
populations "flushed" into areas of the middle Amazon.
Apistogramma-velifera-Complex
The species of the A.-velifera-complex show characteristics of both
the A.-pertensis-group and its sibling, the A.-iniridae-group. The
lateral band is fairly broad for a A.-pertensis-group species, more like that
seen on A.-iniridae-group species (1). They, however, show the separate caudal
spot of the A.-pertensis-group (2). The caudal fin on males is
either a modified oval or lyrate, also like that seen on most species of the A.-iniridae-group. The dorsal fin
of males can exhibit characteristics of either the A.-pertensis-complex or A.-iniridae-group.
On A. velifera, for example, the dorsal fin lappets on males are all fused into a sail like filament - except
for the first dorsal spine (3). On A. sp. "Putzer" all of the spines
are fused together like that seen on A.-iniridae-group males.
Interestingly, the infraorbital pore count is variable on species of this complex. Some specimens will have
a full set of four pores, while other specimens of the same species
will show a reduction to three. Some specimens have even been found to
have four pores on one side and three on the other!
The A.-velifera-complex appears to form a ‘bridge’ between the A.-pertensis- and A.-iniridae-groups.
The A.-velifera-complex occurs from the upper Rio Negro, in Brazil to the
middle Río Orinoco, in Colombia and Venezuela, including the Casiquiare
Channel which connects the two river systems together.
Apistogramma-iniridae-Group
Other than the features characteristic to members of the A.-pertensis-group, the A.-iniridae-group
species usually show two or more rows of spots below the lateral band (1).
Some species also exhibit several dark diagonal bars below the lateral band on their posterior flanks
(2). The lateral band extends into the tail, with no caudal spot
(3). All of the dorsal fin lappets are fused together to form a sail-like
dorsal fin (4). All have lyrate tails except A. iniridae
(oval) and A. sp. "Içana" (lyrate or spade shaped). In A. iniridae only rare specimens develop
extensions on some caudal fin rays. All species in the A.-iniridae-group normally possess three infraorbital
pores - an advanced feature. Species of the A.-iniridae-group are notable among the A.-pertensis-lineage
for showing this reduced number of infraorbitals. This is an advanced trait typically seen only on members of
the A.-trifasciata- and A.-diplotaenia-lineages and some unusual species previously noted.
The reduction of infraorbital pores might have occurred independently in the A.-iniridae-group or the
A.-iniridae-group might be the ancestor of these two lineages.
Presently there are four scientifically described and at least seven undescribed species in the group.
The species of the A.-iniridae-group are known to occur only in the
upper Rio Negro of Brazil and closely associated tributaries of the upper Río Orinoco of Colombia and Venezuela.
In this respect, they have a distribution pattern similar to that of the A.-velifera-complex.
Apistogramma-trifasciata-Lineage
Based on the preliminary genetic studies of Miller & Schliewen (2005), the members of Koslowski’s (2002)
A.-trifasciata-lineage and A.-agassizii-lineage form a monophyletic unit separate from other lineages.
In what follows, I will use the name A.-trifasciata-lineage for this unit. It contains much of what in the
past I called advanced species-groups. The species-groups within the A.-trifasciata-lineage contain species
that typically possess a reduced number of infraorbital pores (3 instead of the normal 4). Compared to species belonging to other lineages,
most species within the A.-trifasciata-lineage show other advanced traits like more elongated, less laterally compressed bodies,
males with ornate dorsal and caudal fins, and a behavioral display involving frontal rather than lateral threat display. It should be noted that not all of the species
will show these traits. Some show retrograde ancestral traits, too.
The A.-trifasciata-lineage is composed of nine species-groups. Seven of the species-groups have species with a
complete set of dental pores. These form the A.-trifasciata-sublineage. The other two species-groups belong to
the A.-agassizii-sublineage in which the species exhibit a reduced number of dental pores (4 instead of the normal 5).
The A. trifasciata-lineage appears to be distributed, for the most part, around the periphery of the Amazon Basin,
along the main channel of the Amazon (probably a more recent event), and in the Río Paraguay system. It appears that
a species similar to A. arua is the source from which all members/species of the A.-trifasciata-lineage
originated.
Apistogramma-trifasciata-Sublineage
As mentioned above, the A.-trifasciata-lineage can be subdivided into two sublineages based on one distinctive
characteristic: the number of dental pores typically exhibited by the species. While the A.-trifasciata-sublineage
species typically exhibit only 3 infraorbital pores, they also possess five dental pores, typical of that of other
lineages. The A.-agassizii-sublineage species typically show not only reduced infraorbital pores, but also a
reduction of dental pores from five to four.
While checking the pores on preserved fish is easily done, it is more difficult on live specimens. However, the following
other features can usually be used to separate species of the two sublineages. Species of the
A.-trifasciata-sublineage are usually, but not always, visually more robust, deeper-bodied, and laterally compressed
fish (1). In this respect they have a body shape more typical of the
A.-steindachneri-group. Males of most, but not all, A.-trifasciata-sublineage species possess moderately high,
serrated dorsal fins (2), while most, but not all, A.-agassizii-sublineage
species show a low and even dorsal fin profile, or at most extended spines on the anterior-most part. Although neither
feature is entirely diagnostic for the A.-trifasciata- or A.-agassizii-sublineage, they will indicate the most likely
sublineage to which a species might belong.
The A.-trifasciata-sublineage has seven species-groups that include two species-complexes, plus several unassigned
species that are considered relic ancestors of the A.-trifasciata-lineage. Species of the A.-trifasciata-sublineage
are found throughout the range of the A.-trifasciata-lineage.
Apistogramma arua and other relic ancestral A.-trifasciata-lineage species
Apistogramma arua, A. salpinction, A. cf. salpinction (Itapeaçu) and
A. sp. "Doppelfleck" are medium to moderately large
2½ - 31/8 in./6.5 – 8cm species. Only A. arua has been studied to any extent. The other three,
however, show some features that indicate they might be related. They do not appear to belong to a distinct species-group. Instead,
they show features found in several A.-trifasciata-lineage species-groups. Apistogramma arua, for example, exhibits
a net-like pattern on the flanks (1) similar to that of the A.-brevis-group and a
pattern of black markings roughly similar to that of the species found in the A.-trifasciata-group.
(2). The dark markings of A. salpinction resemble more those of
the A.-cacatuoides-group. The body shape and finnage of all three species are similar to that of
the A.-cacatuoides-group (3). It is possible that these three species
represent relic species of the ancestral A.-trifasciata-lineage species.
All four of the species occur in the Amazon Basin between the Rio Madeira and Rio Tapajós system, a location that is
on the far eastern periphery of the range of the trifasciata-lineage.
Apistogramma-brevis-Group
Species of the A.-brevis-group are composed of tiny to moderately large
(1½ - 3 in./3.5 – 7.5 cm) species. They are characterized by having
moderately deep, slightly laterally compressed bodies. Except for two
species, males of Apistogramma-brevis-group species have highly serrated
dorsal fins (1). The caudal fin is crossed by rows of
fine spots at least in the central part (2). The ventral fins
are unusually short and blunt for males (3). On the flanks, the
posterior edge of the scales are dark and form a net-like pattern (4).
The A.-brevis-group presently includes four scientifically described plus
five undescribed species. It is endemic to the upper Rio Negro of Brazil and Colombia and upper
Río Orinoco of Colombia and Venezuela.
Apistogramma-sp.-"D10"-Group
The Apistogramma-sp.-"D10"-group is composed of species that are hard to define as a species-group because they show few
unique distinguishing features. They do show some plesiomorphs (features shared from a common ancestor)
in which they differ from other groups. As such, the group is comprised of medium to large
(2¾ - 3½ in./6.5 – 10 cm TL) species characterized by having moderately elongate, relatively deep and
laterally compressed (twice as high as wide) bodies, especially in larger males. Depending on the species,
males exhibit dorsal fins that vary from moderately low and even to high and highly serrated. Males, and even
females of some species, develop long tips on the dorsal, anal and ventral
fins (1). The caudal fin is quite variable in form and markings. It
can be round to double-tipped and show either no markings or be crossed by rows of spots. The broad and always
zigzag bordered lateral band (2). can be either separate from the caudal
spot or attached to it only narrowly. The caudal spot is generally rounded and about the same height as the
lateral band, but can expand vertically in aggressive or stressed individuals. Species show a well-developed
lateral spot the same height as the lateral band (3). A series of
vertical abdominal streaks, that vary in intensity depending on mood, occur below the lateral
band (4). The head is proportionally slightly larger than that of typical
Apistogramma (5).
This is most likely a result of being mouthbrooding species.
At first glance, species of the A.-sp.-"D10"-group resemble species of the A.-macmasteri-group of
the A.-regani-lineage. This is most likely due to evolutionary convergence since they live in similar
biotopes. They differ, however, by having a conspicuous lateral spot and normally only 3 infraorbital pores. These
features are characteristics of species belonging to the A.-trifasciata-lineage. They actually appear to
be most closely related to species of the A.-brevis-group. The A.-sp.-"D10"-group differs from
species of the A.-brevis-group by having extended ventral fin tips, which are short and blunt on the males
of the A.-brevis-group, and lack the net-like pattern seen on the flanks of A.-brevis-group species.
Behaviorally, the A.-sp.-"D10"-group also differs from the display behavior of A.-brevis-group
species. The A.-brevis-group species, in frontal display, drop the lower jaw and open the mouth wide. Species
of the A.-sp.-"D10"-group, in frontal display, keep the mouth closed or only slightly open. One species
even lays on its side in frontal display. In some species the males will court the female in a vertical,
tail-standing position. At least two of the species in the A.-sp.-"D10"-group are delayed, larvophylic
mouthbrooders. Eggs are hung in a cave in typical Apistogramma fashion. Once the eggs hatch the female
places the larvae in her mouth where she holds them, except when she is feeding, until the fry become freeswimming.
In this respect the breeding behavior resembles that of species in the A.-barlowi-complex.
The A.-sp.-"D10"-group presently includes three undescribed species.
The group is known only from the upper Rio Vaupés and middle Río Caquetá of Colombia.
Apistogramma-cacatuoides-group
The members of the A.-cacatuoides-group are medium to large (2½ - 3½ in/6.5 – 8 cm) species.
Males are characterized by their robust but slightly elongate and laterally compressed bodies, enlarged
lips (1), extended anterior dorsal fin lappets (except A. staecki)
(2), and usually lyrate caudal fins (3).
All species in the group show a moderately wide lateral band that either extends into the base of the caudal
fin or ends in front of a distinct caudal spot. On species without a caudal spot, the lateral band often narrows
noticeably in the posterior caudal peduncle and then widens again at the base of the caudal fin. This
narrow part of the lateral band often fades away and forms a ‘pseudo caudal spot’ (4).
Like all groups in the A.-trifasciata-lineage, all species of the A.-cacatuoides-group exhibit a
reduced number of infraorbital pores. The males tend to be highly polygamous.
Presently the A.-cacatuoides-group has six, probably more, scientifically described species and at least eight,
probably more, undescribed species. Apistogramma cacatuoides very likely is a superspecies. Many of the
different populations of A. cacatuoides most likely will be found to be separate species after further genetic
testing.
The A.-cacatuoides-group is distributed along the outer fringes of the southern and western Amazon Basin in
Bolivia, Peru, Colombia and extreme western Brazil. It appears that it migrated from the Peruvian Amazon
comparatively recently down the main channel of the Amazon as far east as Santarém, Brazil.
Apistogramma-nijsseni-Group
Species of the A.-nijsseni-group are characterized as moderately
large (3 in./7.5 cm) species with robust, moderately deep and laterally compressed bodies. The head
is relatively large with strongly developed jaws and thick lips (1)
. The species have dark brachiostegial membranes (2) that, when spread wide in frontal display, give the head an even
larger appearance. On males, the shape of the dorsal fin ranges from low and even to high and deeply serrated.
The tips of the soft parts of both the dorsal and anal fins are short and relatively
blunt (3). Most females develop a brood dress with large dark patches
on the gill covers, flanks or abdomen, and caudal peduncle (4). Males
can show this pattern, too, but it is often hidden under a blue body sheen. The lateral band almost never is
visible except in juvenile species. The caudal fin is typically round on both sexes, but some species have
broadly double-tipped caudals on one or both sexes. Both sexes of many species develop a red/orange band around
the outer margin of the caudal fin (5), except for species with
lyrate tails. These usually show the red/orange color only on the upper and lower margins of the tail.
The distribution of the A.-nijsseni-group occurs in isolated blackwater tributaries of the Río Marañon,
Río Ucayali, Río Nanay, Río Napo, and Río Caquetá of Peru, Ecuador and Colombia, which drain to ancient Napo Superfan.
Presently, there are nine scientifically described species and three undescribed species within the group.
Apistogramma-norberti-group
The species of the A.-norberti-group are moderately large (3 in/7.5 cm TL) robust species that show
a mix of characteristics found in the A.-nijsseni-, A.-cacatuoides- and A.-atahualpa-groups.
They exhibit a body form similar, but deeper/higher backed, than that of species in the A.-cacatuoides-group.
The finnage is similar to that of species found in the A.-atahualpa-group, and frontal display is similar to
that seen in the A.-nijsseni-group. The head is deeper than that seen on species of the A.-cacatuoides-group
(1), and more similar to that seen on some species of the
A.-atahualpa-group. To a greater degree than those of the A.-atahualpa-group and more like the
A.-cacatuoides-group, A.-norberti-group species show enlarged, usually orange to red lips, on males
(2). The dorsal fin of males exhibits extensions more like those seen in
the A.-atahualpa-group. The anterior part has moderately high lappets and the remainder is lower and slightly
serrated (3). Most but not all specimens of both sexes display a large dark patch
on the soft part of the dorsal fin (4). Very few other species exhibit such a patch.
The ventral fins develop tips that are similar to those seen on the A.-atahualpa-group, but shorter than those typical
of the A.-cacatuoides-group. The caudal fin, which is crossed by vertical rows of spots, can be round or double-tipped
like those seen on species of the A.-atahualpa-group. The lateral band is broader than that seen on the
A.-cacatuoides- and A.-atahualpa-group (5). The lateral spot at times
appear as a light spot on the dark lateral band, similar to that seen on some species in the closely related
A.-cacatuoides-, A.-atahualpa- and A.-nijsseni- groups. In certain moods the lateral spot expands
above the lateral band a short distance, forming a small flank patch (6). There
are 3 rows of wavy abdominal stripes (7) below the lateral band, similar to those
seen on species of the A.-cacatuoides-group. In aggressive frontal display, males of the A.-norberti-group
expand the brachiostegial membrane, like species of the A.-nijsseni-group (8).
Presently, there are only two recognized species in the A.-norberti-group – one scientifically described and one
undescribed. They display a disjunct pattern of distribution. Apistogramma norberti occurs in the lower Río Ucayali
drainage (Río Tahuayo and Río Tamshiyacu), while the undescribed A. cf. norberti (Lyretail) is found in
streams entering the Amazon near Leticia, Colombia.
Apistogramma-atahualpa-Group
The species of the A.-atahualpa-group are large (> 3½ in./8 cm), robust species. They probably arose
from a A.-cacatuoides-group species. The shape of the body, dark markings, and finnage are very similar
to those of species in the A.-cacatuoides-group. The head (1) is
noticeably deeper than that seen on A.-cacatuoides-group species. The lips are not as
enlarged (2). The ventral fins of A.-atahualpa-group males develop
extended tips that are shorter than those of the A.-cacatuoides- and A.-nijsseni-group
(3).
I propose two species-complexes in the A.-atahualpa-group, separated mostly on the length of the head. The
enlarged head size in the A.-barlowi-complex is probably a recent adaptation toward primitive
mouthbrooding.
At present the A.-atahualpa-group includes four scientifically described species and at least one that
is undescribed.
All of the species in the group are known to occur in tributaries of the western Amazon of Peru, Colombia and western Brazil that drain the ancient Napo Superfan region.All of the species in the group are known to occur in tributaries of
the Peruvian and the nearby Colombian Amazon that drain the ancient Napo Superfan region.
Apistogramma-atahualpa-Complex
The body of A.-atahualpa-complex species are large (3½ in./8 cm), moderately elongated and slightly
laterally compressed. The dorsal fin develops highly extended anterior dorsal fin lappets
(1). Soft parts of the dorsal and anal fins of males have pointed tips but
are not greatly extended (2). The caudal fin is either round or
double-tipped, either clear or patterned with rows of fine spots. The species show a caudal spot that at times
is joined to the lateral band by a thin dark stripe (3).
There are presently two described species in the A.-atahualpa-complex. Four other forms are known, but
two of these are probably geographic populations of the two described species.
All members of the A.-atahualpa-complex are found in blackwater tributaries of the Río Nanay
between Iquitos and Nauta, Peru, the Río Tapiche on the opposite side of the Amazon, and the Río Galvez.
Apistogramma-barlowi-Complex
The species of the A.-barlowi-complex are very similar to those
of the A.-atahualpa-complex in body size, shape and finnage. Their large body (> 3½ in./8 cm)
is moderately elongated but less laterally compressed than that of species in the A.-brevis-group.
Males have extended anterior dorsal fin lappets (1) and a double
tipped caudal fin, part of which shows spot-rows (2). One unique
feature seen on A.-barlowi-complex species is the unusually large head
(3). The head is approximately one-third of the body’s standard length. This latter feature
is probably a modification toward mouthbrooding. Species in the A.-barlowi-complex show a tendency
at times to be delayed larvophylic mouthbrooders. At other times they breed in a typical
Apistogramma fashion. Environmental factors (substrate, spawning sites, fry predators, etc.) seem
to influence which breeding mode is used.
Presently the A.-barlowi-complex is composed of two scientifically
described species and four still undescribed species.
Its distribution is found in northern tributaries of the Amazon between the mouth of the Río Napo in Peru
and the Rio Jutai(?) in western Brazil.
Apistogramma-trifasciata-Group
The A.-trifasciata-group species in many respects look much like miniature versions of
A.-cacatuoides-complex species. Members of the A.-trifasciata-group are characterized by
the combination of having a small (<2½ in/6.5 cm), moderately elongate and compressed body,
extended anterior dorsal fin lappets (1), long ventral fins
(2) on males, and a round caudal fin (3).
The lateral band is broad in the caudal peduncle, but narrows toward the head (4).
Males are highly territorial and polygamous.
I personally believe that the A.-trifasciata-group is an offshoot of the A.-cacatuoides-group. It
has similarities to A. staecki, a member of the A.-cacatuoides-group. Behaviorally,
A.-trifasciata-group species are much more like A.-cacatuoides-group species in that they are
very territorial and highly polygamous. Their extended, separate, anterior dorsal fin lappets are common to it and
species of the A.-cacatuoides-group. Geographically, the A.-trifasciata-group originates in areas that
overlap those of the A.-cacatuoides-group.
The A.-trifasciata-group has two scientifically described species. It is possible that A. trifasciata
represents a superspecies, composed of several separate but similar looking species.
The A.-trifasciata-group is distributed in the Rio Paraguay/Paraná drainages of Brazil, Paraguay, and Argentina
and tributaries of the Rio Mamoré/Guaporé system of Bolivia and Brazil.
Apistogramma-agassizii-Subcomplex
Species of the agassizii-subcomplex are distinguished from species
of the Broad-Black-Caudal-Seam-subcomplex by the pattern on the caudal fin and from the Netz-subcomplex
by the pattern seen on the flanks. Apistogramma-agassizii-subcomplex males typically have a
spade/lance-shaped caudal pattern of a narrow dark caudal margin, broader light-colored submarginal
band and an interior dark band that is typically wider than that of the dark outer band
(1). This pattern is also seen on males of the Netz-subcomplex.
The agassizii-subcomplex differs visibly from that of the Netz-subcomplex by not exhibiting
the net-like pattern seen on the flanks of Netz-subcomplex males. At most, agassizii-subcomplex
males will show dark margins only on parts of the edges of the scales of the
flanks
(2).
Presently there is only one scientifically described species
(A. agassizii) in the agassizii-subcomplex. However, there are three additional
but scientifically unnamed species recognized by their genetic variance. Besides these four species,
there are at least 10 other forms/populations within the agassizii-subcomplex that are most
likely separate species.
The A.-agassizii-subcomplex species occur exclusively in the upper Amazon of Peru, Colombia,
and Brazil. Forms are found from the lower Río Ucayali and Río Marañon in Peru down to the Colombian
Amazon and then downstream in the Rio Solimões in Brazil to the Rio Negro.
Apistogramma-agassizii-Broad-Black-Caudal-Seam-Subcomplex
Species of the A.-agassizii-Broad-Black-Caudal-Seam (BBCS) -
subcomplex exhibits minor, but visible differences to those of the species of the other two subcomplexes.
When compared to forms in the agassizii- and Netz-subcomplexes, males of the BBCS-subcomplex
appear to have a slightly more slender/elongate (1) body shape.
Except for older, more well-developed, males, the dorsal and anal fin tips are not as long as on species
of the other two subcomplexes. Males typically also have a more blunt spade/lance-shaped caudal fin.
(2).
The scale pattern on flanks of males is similar to that of males of the agassizii-subcomplex.
The feature that distinguishes males of the BBCS-subcomplex is the pattern of bands in the caudal fin.
The pattern is composed of a broad dark caudal margin, broad light-colored submarginal band and an
interior dark band that is noticeably narrower than that of the dark outer band
(3).
At present there are no scientifically described species in the
BCCS-subcomplex. There are at least 8 forms and several color variants that are members of the
subcomplex. Whether or not these color variants are distinct forms or populations of other forms
requires further study.
The BBCS-subcomplex are known only from right bank (southern) tributaries of the lower Amazon, east
of the Rio Purus to the mouth of the Amazon and rivers entering the Atlantic Ocean near Belém, Brazil.
Apistogramma-agassizii-Netz / Net-Subcomplex
The forms of the A.-agassizii-Netz-subcomplex closely
resemble those of the A.-agassizii-subcomplex with only minor differences. In body shape they are
more robust than those of the BBCS-subcomplex and also often appear heavier than forms in the
A.-agassizii-subcomplex (1).
Mature males develop long tips on the dorsal, anal and caudal fins (2).
The most diagnostic feature of the Netz-subcomplex, however, is the net-like pattern on the flanks of
males. This pattern is formed by dark edges that border the anterior edge of each scale, which join the
dark edges of scales above and below (3).
Like species in the BCCS-subcomplex, at present there are no scientifically
described species in the Netz-subcomplex. There are at least 7 undescribed forms that are recognized.
The Netz-subcomplex forms all occur in left bank (northern) tributaries of the Amazon from the Rio Negro
almost to the mouth of the Amazon.
Apistogramma-diplotaenia-Lineage
In spite of the fact that species of the A.-diplotaenia-lineage have many
characteristics in common with members of the A.-agassizii-group, genetic
studies of Miller and Schliewen (2005) indicate that the
A.-diplotaenia-group is not closely related to other species-groups and
possibly represents a separate lineage within the genus.
The species all have infraorbital pores reduced to three and dental pores reduced to four.
Species of the A.-diplotaenia-lineage are found only in tributaries of the middle and upper Rio Negro and the
upper Río Orinoco of Brazil, Colombia, and Venezuela.
Apistogramma-diplotaenia-Group
The species of the A.-diplotaenia-group are moderately small (<2¼ in./6 cm) fish with elongate, nearly fusiform bodies. The
dorsal fin on males is low and even to very slightly serrated (1). The caudal fin is round to
slightly spade/lance shape (2). The unique diagnostic feature of these species is the
"double lateral band" (3). The lateral band is extremely broad over most of the length of the
body. A pale row of scales develops along the central section of this lateral band. This makes the band appear as a double band.
Presently there are two scientifically described species in the species-group.
The species of the A.-diplotaenia-group are found only in tributaries of
the middle and upper Rio Negro and the upper Río Orinoco.
Taeniacara
The genus Taeniacara also shows many physical similarities to species
of the A.-agassizii-sublineage. These include an even more elongated body with a broad lateral band
(1) and lance/spade-shape caudal fin (2) on males. In
many ways it looks much like A. elizabethae with a low dorsal fin (3).It shows a
significant reduction in cephalic pores compared with species of Apistogramma.
Genetic studies by Miller and Schliewen (2005)
indicate that Taeniacara is not closely related to any Apistogramma species-group. It appears that it arose from a common
ancestor with Apistogramma.
Presently the genus is considered to be monotypic, the only species being Taeniacara candidi. Considering the highly disjunct
distribution of this species, in the Rio Negro and southern side of the Amazon, it is likely that the species will eventually be recognized as
being two or more separate species.
Taeniacara is distributed in the middle Amazon drainage between Manaus and Santarém and in the lower and middle Rio Negro of Brazil.
Conclusion
There are now close to 500 recognized species and forms of Apistogramma. With so many different species it is virtually impossible to
easily identify different species. I find that I can reduce the number of possible species I need to consider significantly by first determining
to which of the species-groups it belongs. I consider these species-groups more as descriptive aids than representing true phylogenetic clades.
Still it is likely that these species-groups are monophyletic for the most part. Please do not consider these descriptions as absolute truth.
I am sure that changes will be needed as more data becomes available – as is apparent from earlier editions of this article. I am always
interested in the opinions of other Apistogramma enthusiasts. Only through continued discussion can we more accurately understand the
many species of Apistogramma and their place within the genus.
Acknowlegement
An article of this size and breadth cannot be accomplished without the help of more people than I can acknowlege individually. Still, I want
to thank all of the ichthyologists and hobbyists whose information on species and collecting locations was needed for this article. I especially
wish to thank Tom Christoffersen and Frank Hättich for their help critiquing and proofreading the article. Without their help this article
would not be as complete as it is. Thank you Tom and Frank.
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Mike Wise, October, 2021.