The increase in species-group/complex numbers is mostly due on the discoveries of new species/forms that are related to species not previously assignable to previously 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 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 the 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 very 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 ascertain on live specimens.
dp = dental pores (two pores on the opposite side of the head are not visible); 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.
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 run over the top of the head, eye to eye.
3. Suborbital (Cheek) Stripe, which extends downward from the eye 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 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 midline 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 to zero; five to seven is more typical.
7. Caudal Spot, a blotch on the base on 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 Spot, 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 dark horizontal stripes on the abdomen below the lateral band. These stripes can be continuous and even, wavy, or even 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.
Using primarily 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!
All members of the 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 regani-lineage includes the regani-, alacrina-, macmasteri-groups, and the unassigned species Apistogramma borellii. Apistogrammoides pucallpaensis is also considered part of the regani-lineage.
Species of the 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, 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 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 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 around 20 scientifically described and at least 50 undescribed species within the group - plus Apistogrammoides pucallpaensis. With so many species it's not surprising that the regani-group has been subdivided into seven complexes and even includes several species that are not assignable to any of the complexes.
The 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, scientifically described and at least six undescribed species that can be assigned to the complex.
Species in the 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.
The species of the Xingu-complex are small to moderate in size (<2¾ in./ 7 cm). They show a mix of features seen on both the caetei- and 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 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 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 regani-group species. The caudal spot on Xingu-complex species tends to be small and either round or square (4). The caudal spot on 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 Xingu-complex.
All species of the complex are found in the Rio Xingu except one, which occurs in the upper Rio Tapajós. Another species questionably assigned to the Xingu-complex, A. rubrolineata, occurs in the Río Madre de Dios in Bolivia and Peru. The species A. sp. Itaparaná, reported to be from the Rio Purus, seems to be a population of A. sp. Xingu from the Rio Xingu and most likely doesn’t actually occur in the Rio Purus.
The resticulosa-complex is composed of a group of relatively small species (<2¾ in./7 cm). In addition to the standard 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 caetei-complex. The body, however, is not as robust as that of 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 body usually shows a blue sheen on males. Presently there are two, possibly four, scientifically described species and possibly another dozen or more undescribed species/forms within the complex.
The species of the resticulosa-complex are almost all found south of the main channel of the Amazon. Their distribution includes the Bolivian Amazon and possibly 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.
The species of the commbrae-complex appear to be offshoots of the resticulosa-complex. Members of both complexes show many similarities. The commbrae-complex is comprised of a group of mostly small species (<2¾ in./7 cm). Besides characteristics found on all species of the resticulosa-complex, the species possess a distinctive rhomboid shaped caudal blotch (1). This blotch is formed from the caudal spot that has merged with a highly pigmented part of Bar 7. Four scientifically described species and another possibly separate undescribed species belong to the commbrae-complex.
All are found in the Bolivian Amazon and Rio Paraguay system.
The genus Apistogrammoides, which contains only one species – Apistogrammoides pucallpaensis, is genetically part of the regani-lineage and probably more closely related to a deep-bodied member of the commbrae-complex, like A. linkei. Therefore, it can be considered a complex within the regani-group. It differs from other 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.
Species in the 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 regani-complex are characterized by having a very pale zone that separates the lateral band from the caudal spot (2). There are at least four scientifically described and at least eight undescribed species presently placed within the complex.
Species of the 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 in the lower Ucayali of Peru. Species are also found in Atlantic coastal streams from north of the Amazon to the Guyana/Venezuela border.
The species of the Winkelfleck-complex show features similar to those of the regani- and 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, possibly representing a single undescribed species, are presently known.
The distribution of the Winkelfleck-complex are inexactly known. One form is known to occur in tributaries of the Río Nanay (Peru); another was collected in southern tributaries of the Amazon between the Río Orosa in Peru and Leticia, Colombia.
The species of the eunotus-complex are all moderately large (<3½ in/9 cm). Their deeper, laterally compressed bodies (1) distinguish them from most members of the regani-complex. The species also show greater sexual dimorphism than seen that in other regani-group complexes. The caudal fin shape is usually round but some species can develop a truncate fin with no, one, or 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 three, scientifically described species and at least another 14 undescribed forms in the complex. This does not include two scientifically described and several undescribed species that show attributes of both the eunotus- and regani-complexes.
All of the species within the eunotus-complex occur in the Río Amazonas drainage of Peru and Colombia, plus one in the neighboring Río Putumayo. Based on secondary features, mostly dark markings, the eunotus-complex can be split into three subcomplexes.
In addition to features seen on all species in the eunotus-complex, the species of the 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 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 eunotus-subcomplex species. It is also seen on some species of the steindachneri- and cacatuoides-groups as well as a couple of other 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 seven undescribed species/forms within the complex.
The eunotus-subcomplex is distributed exclusively in the Peruvian and Colombian Amazon.
The species of the cruzi-subcomplex are similar to eunotus-subcomplex species. They are distinguished by their lack of split vertical bars. The dorsal fin on males is lower and rarely shows serrated spines (1). The posterior extension 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 is only one scientifically described species (A. cruzi) and at least three, possibly more, undescribed species in the subcomplex.
The cruzi-subcomplex is distributed in tributaries of the Amazon below the Río Ucayali in Peru and Ecuador as well as tributaries of the Rio Putumayo in Peru and Colombia.
Very few characteristics separate members of the Pebas-subcomplex from those of the 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 Pebas-subcomplex are usually present, but not as prominent as on cruzi-subcomplex species. Species in the Pebas-subcomplex are often more colorful. The species of the Pebas-subcomplex can be easily separated from those of the cruzi-subcomplex by one feature. The Pebas-subcomplex species form a caudal blotch from the caudal spot and part of the 7th vertical bar (1), similar to that of the commbrae-complex.
Species of the Pebas-subcomplex are known only from northern tributaries of the Peruvian Amazon between the Río Napo and the Río Ampiyacu.
Apistogramma borellii is a non-allied species from the Rio 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 Rio Paraguay. Perhaps reduction in sensory pores may be related to subtle differences found in the environment of the Rio Paraguay, although it may also be a chance mutation like that which occurred in the pertensis-group. In many respects A. borellii appears to be a deeper bodied, higher finned, offshoot of the macmasteri-group.
Only one other form might be a member of this group. This is Apistogramma sp. Rio 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.Paraguay III was found in a shipment of A. borellii from the upper Rio Paraguay. There is a good possibility that it is only an aberrant A. borellii.
Apistogramma borellii is distributed throughout much of the Rio Paraguay/Paraná drainage, from the southern Mato Grosso of southern Brazil to the city of Corrientes in northern Argentina. It is 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.
The species of alacrina-group show features that indicate that they may form a bridge between species of the macmasteri-group and those of the eunotus-complex. Most are moderately large (3 in./7.5 cm). Their 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 macmasteri-group than the even bordered lateral band of 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 macmasteri-group. In this respect, it is more similar to that of males of the cruzi-subcomplex. Females of the alacrina-group exhibit the yellow with black checkered brood pattern characteristic of the macmasteri-group and cruzi –subcomplex. Like females of the cruzi-subcomplex, they do not develop a black ventral stripe typical for females of the macmasteri-group. Instead, females develop at most an anal blotch. A pectoral blotch is sometimes part of the female’s brood dress. The males, like males of macmasteri-group species, are highly polygamous. This is an ancestral species-group, with four infraorbital and five dental pores. There is one scientifically described species (A. alacrina) and possibly four undescribed species in the group.
The alacrina-group is distributed in northeastern Ecuador and southeastern Colombia. Species are found in tributaries of both the Orinoco and Amazon.
The macmasteri-group is closely related to the regani-group. It replaces the regani-group in the Orinoco Basin. It is characterized by moderately large (<3½ in/9 cm), 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 from the chin to the vent, or at least a dark spot at the insertion of the ventral fins. All species in the macmasteri-group have the ancestral four infraorbital and five dental pores. Presently there are five scientifically described and at least three, more likely many more, undescribed species in the group. There are many geographic color variants that may or may not be distinct species. More distribution data are needed to clarify this problem.
The species of the macmasteri-group are found exclusively within the drainage of the Río Orinoco. They are distributed from its headwaters in the foothills of Andes and in the Guiana Highlands in Colombia and Venezuela all the way to its mouth of the Orinoco on the Caribbean coast of Venezuela.
The species of the macmasteri-group can be divided into two complexes, based on the design of the lateral band and other color markings.
Males of the hongsloi-complex can be recognized by the 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 ladder/lattice-like 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 hongsloi-complex all show a round caudal fin.
All known forms in the hongsloi-complex occur in the lower courses of Orinoco tributaries of Colombia and Venezuela. They are found together with macmasteri-complex species only in the Río Caura.
In contrast to the hongsloi-complex, species of the macmasteri-complex develop a zigzag lateral band (1) and, shows no ventral band. Males show an upper and lower red and/or black caudal fin borders (2). The tail can be round to squared-off/truncate with one or two short extensions.
The macmasteri-complex is found in tributaries of the Orinoco above areas that contain hongsloi-complex forms. Exceptions are A. guttata, from the delta of the Orinoco and A. sp. Caura from the Río Caura.
Based on the genetic studies of Miller & Schliewen (2005), the pertensis-lineage is composed of the steindachneri-group and its sister taxon, A. wapisana, plus the pertensis-group and its sister taxa, the iniridae-group. Unlike the regani-lineage, species in the pertensis-lineage show a pronounced lateral spot.
The steindachneri-group is comprised of medium to large species (3-4 in./7.5-10 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, the vertical bars appear as split narrow vertical bands below the lateral band. A large flank patch (2) situated on or immediately above the narrow, rarely visible, lateral band (3) is characteristic of 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 steindachneri-group.
The 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 wapisana is an unusually tiny species (< 1½ in./3.5 cm) showing a mix of features exhibited by the steindachneri- and pertensis-groups. Like members of the 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 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 unique by having reversed sexual dimorphism, where the male is slightly smaller than the females. Also unusual is its breeding behavior in which, unlike in mostApistogramma species, the male of 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 steindachneri-group (Guyana, Surinam, Rio Negro) and the pertensis-group (middle to lower Amazon).
The pertensis-group is comprised of a series of tiny to large (1½ - 3 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 typically are round, lyrate, spade or even three-lobed shaped and covered by rows of spots. Vertical bars are only visible on stressed fish. There is little sexual dimorphism and for the most part the species are preferentially monogamous. There are five scientifically described and at least six undescribed species in the pertensis-group, which is split into two complexes.
Distribution of the 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 Rio Orinoco.
Besides the characteristics found on all members of the pertensis-group, males of the 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. Pertensis-complex species typically show no black pigmentation on the flanks except for the lateral band and lateral spot. The dorsal fin usually has the first 3 spines separated from a sail like fin (1). All scientifically described species have the ancestral four infraorbital pores and five dental pores.
This species-complex occurs in the Orinoco and Rio Negro drainage, with populations "flushed" into areas of the middle Amazon.
The two species of the velifera-complex show characteristics of both the pertensis-group and its sibling, the iniridae-group. The lateral band is quite broad for a pertensis-group species, more like that seen on iniridae-group species (1). They, however, show the separated caudal spot of the pertensis-group (2). They often – but not always – show reduced infraorbital pores, at least on one side. The caudal fin on males is either a modified oval or lyrate, also like that of the iniridae-group. Except for the first dorsal spine, the dorsal fin lappets on males are all fused into a sail like filament (3), again like that on 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 velifera-complex appears to form a ‘bridge’ between the pertensis- and iniridae-groups.
The 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.
Other than the features characteristic to members of the pertensis-group, the iniridae-complex species usually exhibit several dark diagonal bars below the lateral band on their posterior flanks (1). The lateral band extends into the tail, with no caudal spot (2). All of the dorsal fin lappets are fused together to form a sail-like dorsal fin (3). Even the first lappet – unlike that of the velifera-complex species – is part of the sailfin. All have lyrate tails except A. iniridae. In this species only rare specimens develop extensions on some caudal fin rays. All members of the iniridae-complex possess three infraorbital pores - an advanced feature. Species of the iniridae-complex are notable among the pertensis-lineage for consistently possessing a reduced number of infraorbital. This is an advanced trait seen only members of the trifasciata-lineage and some unusual species previously noted. The reduction of infraorbital pores might have occurred independently in the iniridae-complex or the iniridae-complex might be the ancestor of the trifasciata-lineage.
The species of the iniridae-complex are known to occur only in the upper Rio Negro of Brazil and closely associated tributaries of the upper Rio Orinoco of Colombia and Venezuela. In this respect, they have a distribution pattern similar to that of the velifera-complex.
According to Miller and Schliewen (2005), the trifasciata-lineage is a monophyletic unit that contains much of what in the past I called advanced species-groups. The species-groups within the trifasciata-lineage contain species that typically possess a reduced number of infraorbital pores (3). Most species within the lineage show other advanced traits like 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 trifasciata-lineage is composed of eight species-groups. Six of the species-groups have species with a complete set of dental pores (5). The other three species-groups belong to the agassizii-sub-lineage in which the species exhibit a reduced number of dental pores (4). The 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 trifasciata-lineage originated.
Apistogramma arua is a medium sized 2½ - 3? in./6.5 – 8cm species. It does not appear to belong to any species-group. Instead, it shows features found in several trifasciata-lineage species-groups. This species exhibits a net-like pattern on the flanks (1) similar to that of the brevis-group. The body shape and finnage is similar to that of the cacatuoides-group (2) and has a pattern of black markings roughly similar to that of the species found in the trifasciata-group (3). It is possible that A. arua represents a relic species of the ancestral trifasciata-lineage species. It is possible that the recently described species A. salpintion is more closely related to A. arua than the cacatuoides-group. More study is needed.
Apistogramma arua occurs in the lower Rio Tapajós system, a location that is on the far eastern periphery of the range of the trifasciata-lineage.
Species of the brevis-group is 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 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 brevis-group presently includes two scientifically described plus three, possibly more, undescribed species. It is endemic to the upper Rio Negro of Brazil and upper Río Orinoco of Colombia and Venezuela.
The species of the atahualpa-group are moderately large (> 3½ in./8 cm), robust species. They probably arose as a western offshoot of the brevis-group, but it is also possible that they arose from a cacatuoides-group species. The shape of the body, dark markings, and finnage are very similar to those of species in the cacatuoides-group. The head (1) is noticeably deeper than that seen on cacatuoides-group species. The lips are not as enlarged (2). The ventral fins of atahualpa-group males develop extended tips (3), unlike males of the brevis-group. I propose two species-complexes in the atahualpa-group, separated mostly on the length of the head. The enlarged head size in the barlowi-complex is probably a recent adaptation toward primitive mouthbrooding.
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.
The body of atahualpa-complex species is moderately 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 atahualpa-complex. Two other forms are known, but are probably only geographic populations of the two described species.
All members of the atahualpa-complex are found in blackwater tributaries, in a roughly northwest-southeast band from the Río Nanay around Iquitos, Peru, southeast into the Río Tamshiyacu and Río Tapiche drainages on the opposite side of the Amazon, and then eastward over the altura (hilly landscape that is never inundated) into the Río Galvezi, a tributary of the Río Yavari.
The species of the barlowi-complex are very similar to those of the atahualpa-complex in body size, shape and finnage. Their moderately large body (> 3½ in./8 cm) is moderately elongated but less laterally compressed than that of species in the brevis-group. Males have extended anterior dorsal fin lappets (1) and a double tipped, spotted portions of the caudal fin (2). One unique feature seen on 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 barlowi-complex show a tendency at times to being 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.
The barlowi-complex consists of one described and one undescribed species. Its distribution is found in northern tributaries of the Amazon between the Río Ampiyacu in Peru and the Colombian Amazon around Leticia.
Species of the nijsseni-group are characterized by 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. The caudal fin is typically round on both sexes, but some species have a broadly double-tipped caudal on one or both sexes. Both sexes of most 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 color only on the upper and lower margins of the tail.
The distribution of the nijsseni-group occurs in isolated blackwater tributaries of the Río Marañon, Río Ucayali, Río Nanay and Río Napo of Peru, which drain to ancient Napo Superfan.
The members of the cacatuoides-group are medium to moderately larger (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 (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 trifasciata-lineage, all species of the cacatuoides-group exhibit a reduced number of infraorbital pores. The males are highly polygamous. The cacatuoides-group has four, possibly five, scientifically described species and at least two, probably more, undescribed species.
The cacatuoides-group is distributed along the outer fringes of the southern and western Amazon Basin in Bolivia, Peru, 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.
The trifasciata-group species in many respects look much like miniature versions of cacatuoides-complex species. Members of the 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 trifasciata-group is an offshoot of the cacatuoides-group. It has similarities to A. staecki, a member of the cacatuoides-group. Behaviorally, trifasciata-group species are much more like cacatuoides-group species in that they are very territorial and highly polygamous. Their reduced infraorbital pore count and extended, separate, anterior dorsal fin lappets are common to it and species of the cacatuoides-group. Geographically, the trifasciata originates in areas that overlap those of the cacatuoides-group. The trifasciata-group has two scientifically described and possibly one undescribed species.
The 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.
The agassizii-sub-lineage is part of the trifasciata-lineage. Like species of the trifasciata-lineage, the species of the agassizii-sub-lineage typically show advanced traits like infraorbital pores reduced to three, elongated, less laterally compressed bodies, males with ornate dorsal and caudal fins, a distinct lateral spot, and a behavioral display involving frontal rather than lateral threat display. In addition to these traits, they all show the number of dental pores reduced from five to four. The males also show the ‘agassizii lip spot’. This spot is a metallic blue patch situated on the lower part of the upper lip near the corner of the mouth.
The agassizii-sub-lineage has four species-groups plus Apistogramma elizabethae. The species of the sub-lineage probably originated in the middle Amazon region of Brazil. The seemingly more primitive species are now found in the upper reaches of Rio Negro and Rio Madeira. From there they migrated west into the Peruvian Amazon and east into the lower Amazon and Rio Tocantins.
Males of Apistogramma elizabethae are moderately large (3 in./ 7.5 cm) and characterized by having a lyrate caudal tail fin that frequently changes to a spade/lance shaped fin when the central caudal rays grow beyond the lyretail tips (1). The dorsal fin on males develops two highly elongated spines that are often more than twice the length of the other spines (2). The lateral band is wide with one or more very pale metallic abdominal bands below the lateral band. Females typically show two squarish flank spots (3) - the typical lateral spot on Bar 3 and a slightly smaller spot on Bar 2. These two spots are also visible on subdominant/stressed males.
Many authors consider A. elizabethae the most primitive form of the agassizii-sub-lineage. There is another possible form similar to A. elizabethae that was pictured in a Japanese aquarium magazine over a decade ago. It conforms to A. elizabethae in all respects except that the dorsal fin shows no extended spines. Instead, the dorsal fin is low and even, similar to that of A. agassizii. Since similar specimens have not been found, it is possible that the fish was a specimen of A. elizabethae with a damaged dorsal fin.
Apistogramma elizabethae is found in the Rio Uaupés and Rio Içana in the upper Rio Negro.
The species of the gibbiceps-group are medium size fish (<3 in/7.5 cm) characterized by their elongate, almost fusiform, body. The dorsal fin on males is typically low and even to slightly serrated, although some populations develop slight extensions on two of the three anteriormost dorsal spines (1). The body shows broad slightly diagonal abdominal bars/stripes that extend across most of the lower flanks below a prominent lateral band (2). Males possess a lyrate caudal fin with a pattern of longitudinal stripes (3). Species within this species-group all have only three infraorbital pores and four dental pores. There is at least one scientifically described, but probably actually two, species in the gibbiceps-group.
All species in this group are found in the middle Rio Negro, as well as tributaries of the Rio Branco.
Species of the bitaeniata-complex include fairly large species (3½ in./8.5 cm) with an elongate, moderately fusiform body. Males of most species show double-tipped to lyrate caudal fins. The dorsal fin shows even, serrated or elongated anterior lappets. The ventral fin tips are long (1), and the flanks show one to three broad abdominal bands (2) below a broad lateral band. I split the bitaeniata-group into two species-complexes based on shape of the dorsal fin and species distribution.
The bitaeniata-group is restricted to black water drainages, mostly near the main channel of the upper and middle Amazon in Peru, Colombia, and Brazil as well as throughout the Rio Negro drainage of Brazil.
The paucisquamis-complex is characterized by the traits common to the bitaeniata-group, except that there are two or three abdominal bands, never only one (1), a dorsal fin on males that is low and even to slightly serrated (2), and typically a lyrate caudal fin (3). There are two scientifically described and two undescribed species presently in the complex.
The species of the paucisquamis-complex are found only in tributaries of the Rio Negro.
The bitaeniata-complex is characterized by the traits of the bitaeniata-group, except that there is only one abdominal band, never more(1), a dorsal fin on males typically with highly extended anterior spines (2), and double tipped caudal fin (3). The exception to this is A. sp. Caño de la Libertad, which shows a moderately high serrated dorsal and round caudal, with a very faint second abdominal stripe. It appears to be a form intermediate between the two complexes. There are two scientifically described and one, possibly two, undescribed species presently in the complex.
The species of the bitaeniata-complex are found in black water drainages near the main channel of the Amazon from the Río Marañon in Peru to the Rio Tapajós in Brazil. The only exception is A. sp. Caño de la Libertad, which is found in the Río Apaporis (Caquetá system) in Colombia.
The agassizii-group is comprised of a number of moderately large (<3½ in./9 cm), elongate species with a broad lateral band (1), a prominent lateral spot (2), and dark head stripes (3). The caudal fin of males is either round or spade/lance shaped. The dorsal fin is low and even (4). They are polygamous species. Like all other species-group in the agassizii-sub-lineage, the member species have only three infraorbital and four dental pores. The agassizii-group presently has three scientifically described and possibly more than a dozen undescribed species split into two complexes.
The agassizii-group is distributed throughout most of the Amazon basin. Most occur close to the main channel of the Amazon. Other more distant ranges include much of the Rio Madeira/Purus and Rio Negro systems, and some Atlantic coastal streams immediately south of the mouth of the Amazon Delta.
All species of the pulchra-complex possess a round caudal fin (1) and low even dorsal fin on both sexes. The caudal pattern on males is typically formed from concentric rows of spots (2). The outer margin of the caudal fin might show some color, but not the multiple submarginal bands seen on members of the agassizii-complex. The flanks of the body are crossed by a broad lateral band and scales on the body typically show dark edges that present a net-like appearance.
The pulchra-complex is found in mostly blackwater biotopes of the Rio Branco (Rio Negro system), Rio Uatumã, and Rio Madeira systems of Brazil. Where species of the pulchra- and agassizii-complexes are found close together, the pulchra-complex species seem to occur in the less hospitable locations. It is possible that agassizii-complex species out competed pulchra-complex species for the more desirable biotopes.
Species in the agassizii-complex possess an oval to spade-shape caudal fin (1) and low, even, dorsal fin. Some populations show a very faint abdominal band below the lateral band, especially on females. This abdominal band, however, is never as distinct as those on members of the bitaeniata-group. The caudal fins of males display two or more colored submarginal bands (2). The interior of the caudal fin can show irregular markings, but almost never show even rows of spots typically visible on most species of the pulchra-complex.
The agassizii-complex has a very wide distribution. It is found in the Rio Negro, Rio Madeira/Purus, the Río Amazonas of Peru, and the Brazilian Solimðes/Amazon/Rio Tocantins as far east as Belem, plus coastal streams along the Atlantic near the Amazon Delta.
In spite of the fact that species of the diplotaenia-lineage have many characteristics in common with members of the agassizii-group, genetic studies of Miller and Schliewen (2005) indicate that the 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 pore reduced to four.
Species of the diplotaenia-lineage are found only in tributaries of the middle and upper Rio Negro and the upper Río Orinoco.
The species of the species of the diplotaenia-group are 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 this lateral band. This makes the band appear as a double band. There presently is one scientifically described and one undescribed species in the species-group.
The species of the diplotaenia-group are found only in tributaries of the middle and upper Rio Negro and the upper Río Orinoco.
The genus Taeniacara also shows many physical similarities to species of the agassizii-sublineage. These include an elongated body with a broad lateral band (1) and lance/spade 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 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 withApistogramma.
Taeniacara is distributed in the middle Amazon drainage between Manaus and Santarém and in the lower and middle Rio Negro.
When trying to identify specimens of Apistogramma, I find that I can reduce the number of possible species significantly by first determining to which of these species-groups it belongs. I consider these species-groups more as descriptive aids than representing true phylogenetic clades. Still it is most likely that these species-groups are monophyletic for the most part. Do not consider these descriptions as absolute truth. I am sure that changes will be needed as more data becomes available. 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.
Goldstein, R. J. 1970. Cichlid Notes. T.F.H. Mag. 18(12): 78-81.
Koslowski, Ingo. 1985. Die Buntbarsche der Neuen Weld — Zwergcichliden. Essen. Reimer Hobbing GmbH. 192 pp.
______________. 2002. Die Buntbarsche Amerikas. Band 2: Apistogramma & Co. Verlag Eugen Ulmer GmbH & Co. Stuttgart. 318p.
Kullander, S. O. 1980. A taxonomical study of the genus Apistogramma Regan, with a revision of Brazilian and Peruvian species (Teleostei: Percoidei: Cichlidae). 152 pp. Bonn. Zool. Monogr. 14.
Meinken, Hermann. 1962. Ein neue Apistogramma-Art aus dem mittleren Amazonas-Gebiet, zugleich mit dem Versuch einer Übersicht über die Gattung (Pisces, Percoidea, Cichlidae). Senk. biol. 43(2): 137-143.
Miller, Michael & Ulrich Schliewen. 2005. The molecular phylogeny of the genus Apistogramma – a working hypothesis. In Stawikowski, Rainer (ed). Südamerikanische Zwergcichliden/South American Dwarf Cichlid. DATZ Sonderheft/Special Pub. Eugen Ulmer KG, Stuttgart. p 22-25.
Ready, J. S., I. Sampaio, H. Schneider, C. Vinson, T. Dos Santos, & G. F. Turner. 2006. Colour forms of Amazonian cichlid fish represent reproductively isolated species. J. Evol. Biol. 19(4): 1139-1148.
Römer, Uwe. 2006a. Cichlid Atlas. Volume 2: Natural History of South American Dwarf Cichlids Part 2. Mergus Verlag GmbH. Melle. 1319p.
__________. 2006b. Cichliden Atlas. Band 2: Naturgeschichte der Zwergbuntbarsches Südamerikas Teil 2. Mergus Verlag GmbH. Melle. 1319p.
Schmettkamp, Werner. 1982. Die Zwergcichliden Südamerikas. Landbuch-Verlag GmbH, Hannover. 176 p.
Wise, Mike. 1990. Description, Distribution, and a proposed phylogeny of Apistogramma species-groups. The Apisto-gram 9(1) (#33): 4-10.
_________. 2002. Description, Distribution, and a proposed phylogeny of Apistogramma species-groups revisited. Apistogramma Study Group web site: http://www.apisto.com/phylo/phylobody.html