Uwe Römer and Frank Warzel

aqua, Journal of Ichthyology and Aquatic Biology

Apistogramma arua sp. n. (Teleostei: Perciformes: Cichlidae), a new species of dwarf from the Rio Arapiuns system, Para State, Brazil.

by Uwe Römer 1 and Frank Warzel 2

1) Universität Bielefeld, Fakultät für Biologie, Postfach 100131, D-33501 Bielefeld, Germany 2) Im Sampel 38, D-55246 Mainz-Kostheim, Germany

Accepted: 7.09.1998 Keywords dans le cours inférieur du Rio Arua. Cette espèce rela - arua, new species, Brazil, Rio tivement petite (mâles jusqu’à 45 mm de L. S.) pourrait Arapiuns, Rio Arua, Cichlidae, systematics. être apparentée au complexe A. cacatuoides sensu stricto ou au groupe d’ A. trifasciata mais pour le moment Abstract sa position dans le genre est incertae sedis. Apistogramma arua sp. n. is described on the basis of A. arua sp. n. est caractérisé par une tache en forme de four specimens collected in a small igarapé near Arua coin sur la partie abdominale des flancs, sous la ligne in the lower course of the Rio Arua. This relatively small latérale, qui se transforme parfois, selon l’humeur de species (males up to 45 mm SL) may be related to the l’, en une ligne ou bande allant de l’opercule à species of the A. cacatuoides complex sensu stricto as l’extrémité antérieure de la nageoire anale ou en trois well as to the A. trifasciata -group, but at the time has to bandes abdominales indistinctes formées de trois be placed incertae sedis within the genus. A. arua rangées de taches en demi-lune. Les mâles possèdent sp. n. is characterised by a wedge-shaped spot on the en outre une nageoire caudale bifide et des extensions abdominal flank beneath the lateral band, which some - de la membrane entre les 6 à 8 premiers rayons de la times, depending on mood, is modified to a line or band nageoire dorsale. between the gill cover and the frontal base of the anal fin, or to three indistinct abdominal bands formed by Sommario three rows of half-moon-shaped spots. Males addition - L’ Apistogramma arua sp. n. viene descritto sulla base ally exhibit a forked caudal fin and extended mem - di quattro esemplari raccolti in un piccolo igarapé vici - branes to the first 5-7 dorsal fin lappets. no ad Arua nel corso inferiore del Rio Arua. Questa specie relativamente piccola (i maschi possono essere Zusammenfassung lunghi fino a 45 mm) può essere paragonata alla specie Apistogramma arua sp. n. wird beschrieben basiert auf del A. cacatuoides complex sensu stricto nonché al vier Exemplaren, die in einem kleinen igarapé in der gruppo del A. trifasciata, ma allo stesso tempo non si Nähe von Arua im unteren Lauf des Rio Arua gefunden sa con certezza se il genus A. arua sp. n. sia caratter - wurden. Diese ziemlich kleine Spezies (Männchen max - izzato da una macchia a forma di cuneo sull’addome imal 45 mm SL) kann sowohl verwandt sein mit den sotto alla banda laterale che, talvolta, a seconda dello Arten des A. cacatuoides Komplexes aber auch der A. stato d’animo viene modificato in una linea o banda tra trifasciata -Gruppe zugerechnet werden. Man ist noch la branchia e la base frontale della pinna anale, oppure unschlüssig, wohin genau die Art innerhalb der Gattung in tre indistinte bande addominali formate da tre file di zu plazieren ist. Ein keilförmiger Fleck an der Flanke des macchie a forma di mezza luna. Inoltre i maschi Bauches unterhalb des seitlichen Bandes charakter - mostrano una pinna caudale biforcuta e membrane isiert den A. arua sp. n. Je nach Stimmung verändert estese fino ai primi lembi della pinna dorsale. sich dieser Fleck zu einer Linie oder in einen Streifen zwischen Kiemendeckel und dem vorderen Ansatz der Introduction hinteren Flosse. Oder es entstehen drei undeutliche The neotropical cichlid genus Apistogramma includes Bänder am Unterbauch, die sich aus drei Reihen halb - some 50 species currently regarded as valid. In addi - mondförmiger Punkte zusammensetzen. Zusätzlich tion at least 40 other forms have been known in the sind Männchen mit einer gegabelten Schwanzflosse aquarium hobby for some time, but have yet to be sci - und verlängerten Häutchen bis zu den ersten 5 - 7 Lap - entifically classified. The new species described herein, pen der Rückenflossen ausgestattet . however, has hitherto been unknown to both aquarists and scientists alike. A small number of specimens, of Résumé which just a single female survived, were imported pri - Apistogramma arua sp. n. est décrit à partir de 4 spéci - vately to Germany in 1993 (Seidel pers. comm.). mens récoltés dans un petit iguarapé proche d’Arua It was not until 1995 that further specimens were

45 aqua vol. 3 no. 2 - 1998 Apistogramma arua sp. n. captured and successfully transported alive to Europe. mens, lodging these with, but not as part of, the type In 1996 Seidel brought back additional live individuals series (as has already been done with, for example, following an expedition to the Arua. the characin Tucanoichthys tucano Gery & Römer, The species has subsequently become generally 1997). available in the aquarium hobby following the simulta - This applies especially to forms which exhibit import- neous first breeding successes by Lowe and one of ant diagnostic characters during their ontogenesis, for the authors (UR), followed somewhat later by that of example, A. panduro Römer, 1997 and the species Seidel, and has recently appeared in aquarium litera - described herein, with any characteristics observed in ture for the first time (Stawikoswki 1997; Seidel 1997) aquarium-raised individuals being taken into considera - under the trivial names Apistogramma species "Arua" tion. Naturally this will result in a significant increase in and Arua- Apistogramma. For this reason, and the researcher's workload, but should, given the because it occupies a special position in the evaluation increasing interest in the investigation of this genus of of the systematic connections between different , prove important in preventing easily avoided groups within the genus, and, moreover, is easily dif - problems during the identification and differentiation of ferentiated from all other members of the genus known new species. to date, it is described herein despite the relatively small amount of collected material available. In addi - Material and Methods tion, following the precedents set by various authors Counts and measurements are in accordance with (Kullander 1980 & 1986; Koslowski 1985a; Linke & the methods described by Kullander (1979, 1980a, Staeck 1992; Römer 1994 & in press), particular 1980b, 1986) and Römer (1994) in press. The preser - emphasis has been placed on live coloration and vation and preparation of the material investigated fol - mood-related patterns, based on extensive aquarium lows the method described by Römer (1994). observations, as these are virtually indispensable for ZFMK18601 and ZFMK18605 were preserved in 10% the accurate identification of the majority of Apis - formalin, the remainder of the specimens in 75% togramma species (especially live specimens). In ethanol. The material investigated has been or will be order to keep the text on live coloration as brief as pos - deposited as follows: the holotype in the Museu de sible, numerous colour illustrations have been used in Zoologia de Universidade de São Paulo in São Paulo, the present work. Brazil (MZUSP), the paratypes in the Zoologisches In recent years, moreover, it has been demonstrated Forschungsinstitut und Museum Alexander König in that the identification of Apistogramma species from Bonn, Germany (ZFMK). Additional comparative mate - descriptions based solely on wild-caught material can rial was deposited at, or inspected from Institute Royale be extraordinarily problematical. Many species do not de Science Naturelle Bruxells (IRSNB) in Brussels, Bel - develop all the relevant diagnostic characters until a gium, and the Forschungsinstitut und Museum Senck - certain size has been attained, which is also the case enberg in Frankfurt, Germany (SMF). in the species described herein. Recent important examples of this phenomenon are Apistogramma arua sp. n. Römer & Warzel A. pulchra Kullander, 1980 and A. uaupesi Kullander, (Figs. 1-2) 1980, in which adult males exhibit a forked tail, although the caudal fin is described as rounded in the Holotype: male, 44.4 mm SL (MZUSP, transferred, but original description. A further "critical" form is A. eliza - number not yet available), collected, live, on 14th Sept- bethae Kullander, 1980, which Römer (1993), follow - ember 1995 some 2.5 km upstream of the village of ing re-examination of the holotype and observation of the development of aquarium specimens, found to deviate from the data given in the original description, in that it exhibits a particularly striking age-related polymorphism of the caudal fin (Römer 1993, 1994, & in press). Furthermore A. parva Ahl, 1931, described from two (female?) juveniles, cannot in fact be differ - entiated from A. agassizii (Steindachner, 1875), for which reason we regard it as a junior synonym of the latter. Apistogramma roraimae Kullander, 1980, is another species that was described from small speci - mens and thus appeared to be quite distinct from the previously described species. However work is in progress which suggests that it may prove to be con - specific with A. gibbiceps Meinken, 1969. It would thus appear to make sense, when describing new Apisto- Fig. 1. Holotype of Apistogramma arua, on preservation. Photo gramma species, to investigate larger aquarium speci- by Uwe Römer aqua vol. 3 no. 2 - 1998 46 Uwe Römer and Frank Warzel

(ZFMK 17558), male (ZFMK 17561), female (ZFMK 17562), female (ZFMK 17653), sex undetermined (ZFMK 17556), sex undetermined (ZFMK 17555). Apistogramma juruensis Kullander, 1986: 10 speci - mens, 2 males and 8 females (SMF 28188); male, 57.2 mm SL, imported to Milwaukee, USA in autumn 1993 as a contaminant in a shipment of characins, pre - served in July 1996; male, 52.7 mm SL, 3 females, 33.4 mm SL, 35.3 mm SL, and 37.4 mm SL (ZFMK 18584), aquarium material, offspring of the male of 57.2 mm SL, preserved in September 1996, donated by U. Römer. Apistogramma luelingi Kullander, 1976: 2 males and 2 females (ZFMK 17632 - 17635) aquarium material, preserved on 10th October 1987, donated by Fig. 2. Apistogramma arua, live holotype male in shock U. Römer. Apistogramma mendezi Rö mer, 1994: coloration, fully grown adult. Photo by Uwe Römer typed series and 200 additional live specimens from various new localities. Apistogramma meinkeni Arua in a small right-bank affluent of the Rio Arua, a Kullander, 1980: holotype, male (IRSNB (types) 567). tributary of the Rio Arapiuns, Para State, Brazil (approx. Apistogramma moae Kullander, 1980: holotype, male 2°39'27"S, 55°43'24"W). Preserved, after aquarium (IRSNB (types) 586); paratype, male (IRSNB (types) maintenance, in May 1996. Coll. A. Krüger & F. Warzel. 587). Kullander, 1979: 7 males Paratypes: 3 specimens. Female, 34.3 mm SL (ZFMK and 7 females (ZFMK 17636 to 17649), aquarium 18599), collection data as holotype, coll. A. Krüger, F. material, parents imported from the type locality in Warzel, M. Loew, & R. Zgorniak. Male, 34.5 mm SL 1989 by E. Gauglitz, donated by U. Römer. Apisto- (ZFMK 18601) and female, 11.6 mm SL (ZFMK gramma norberti Staeck, 1991: Male (ZFMK 17686), 18605), collection data as for holotype; preserved, after coll. at the type locality in January 1989 by N. Wisheu, aquarium maintenance, in October 1995; coll. as for donated by U. Römer; 4 males and 4 females (ZFMK ZFMK 18599. 17687 - 17694), aquarium specimens, parents import - Additional Material: Apistogramma arua sp. n. (non ed in spring 1989 by N. Wisheu, preserved on 15th types): 15 males and 25 females, aquarium-bred and August 1991, donated by U. Römer. studied while living. Not preserved. Apistogramma Römer, 1997: type series and atahualpa Römer, 1997: type series and 30 additional, a further 200 live specimens of diverse origin. Apisto- live, specimens. Apistogramma bitaeniata Pellegrin, gramma paucisquamis Kullander & Staeck, 1988: 1936: male (SMF 5526), 2 males and 3 females (SMF female, 26.2 mm SL (SMF 9450), originally paratype of 5527 - SMF 5531) (the type series of A. klausewitzi A. gibbiceps. Meinken; 2 males and 2 females (ZFMK Meinken); 2 males and 2 females (ZFMK 17464 - 17468 & ZFMK 17469), for data see Römer, 1994. ZFMK 17467), for data see Römer, 1994. Apistogram - Apistogramma personata Kullander, 1980: holotype, ma brevis Kullander, 1980: holotype, male (IRSNB male (IRSNB (types) 575). Apistogramma pulchra Kul - (types) 570), paratype, probably female (IRSNB (types) lander, 1980: paratype, probably female (IRSNB (types) 573). Apistogramma cacatuoides Hoedeman, 1951: 9 584), plus 15 live specimens, imported in November males and 5 females (ZFMK 17618 -17631), aquarium and December 1996 from the vicinity of Porto Velho, material from parents from Pucallpa, Peru, preserved Brazil. Apistogramma roraimae Kullander, 1980: 1991, donated by U. Römer. Apistogramma elizabethae paratype, sex undetermined (IRSNB (types) 589). Apis - Kullander, 1980: holotype, male (IRSNB (types) 596); togramma staecki Koslowski, 1985a: ZFMK and SMF paratype, male (IRSNB (types) 598); male and 2 type material. Apistogramma steindachneri (Regan, females (ZFMK 17470 - ZFMK 17472), for data see 1906): 14 specimens (ZFMK 17511 to 17524), aquari - Römer, 1 994. Apistogramma gibbiceps Meinken, um material, probably originally imported from 1969: 7 males, 31.9 - 45.6 mm SL (SMF 9441, holo - Venezuela, preserved in December 1988, donated by type, SMF 9442 - SMF 9446 and SMF 9449, U. Römer. Apistogramma trifasciata (Eigenmann & paratypes); 21 specimens, 11.4 - 24.2 mm SL (SMF Kennedy, 1903) (nominate form): 5 males and 3 28189); female (ZFMK 18586), female (ZFMK 18591), females (ZFMK 17733 to 17740), aquarium specimens, male (ZFMK 18594), male (ZFMK 18595), male parents imported from the Pantanal, preserved (ZFMK 18506), female (ZFMK 18597), male (ZFMK between 1986 and 1989, supplied by U. Römer. Apisto- 18598), male (ZFMK 18600), female (ZFMK 18602), gramma maciliensis (Haseman, 1911): 10 males and 5 female (ZFMK 18603), female (ZFMK 18604), female females, imported from the Rio Guaporé area in (ZFMK 18606), female (ZFMK 18607), male (ZFMK November and December 1995 by M. T. Lacerda, 18608), male (ZFMK 18622), male (ZFMK 17552), observed live in the aquarium (for status of this species male (ZFMK 17553), female (ZFMK 17554), female see Römer i n press). Apistogramma uaupesi Kullan -

47 aqua vol. 3 no. 2 - 1998 Apistogramma arua sp. n. der, 1980: holotype, male (IRSNB (types) 594); male Morphological Characters (ZMFK 17476), for data see Römer, 1994. Apis - In comparison with other members of the genus the togramma sp. "Breitbinden": 3 males and 2 females body is relatively deep and noticeably compressed lat - (ZFMK 17720 to 17724), imported in June 1990 from erally. Adult specimens exhibit marked sexual dimor - Puerto Ayacucho on the upper Orinoco (Venezuela), phism. Males are some 2 cm longer than females, donated by U. Römer, plus 20 live specimens studied and, from a length of about 20 mm SL upwards, have in the aquarium. a forked tail and elongation of the membranes of the anterior dorsal. The upper head profile is uniformly Type Locality convex, the lower likewise uniformly rounded, but in a The type locality - and so far the only known locality - rather flatter curve. Mouth terminal, lower jaw slightly is a small igarapé (forest stream), a right-bank affluent protrusive. Lips fairly thick, maxillary extending back of the Rio Arua, upstream of a waterfall near the village past a vertical through the anterior edge of the eye. of Arua in the upper Arapiuns system. The mouth of the Scales generally ctenoid, apart from cycloid scales on igarapé lies about 400 metres downstream of a small the cheeks, upper head, anterior breast region, and landing stage, which can be reached from Arua village caudal fin. 23(+2) scales in the E1 series. The length only via a footpath. of the dorsal spines increases rapidly from the first (the anteriormost) to the sixth. The 6th to 8th spines Diagnosis are about the same length, with the remainder becom - A relatively small (males to 45 mm SL, females to 35 ing progressively slightly shorter. In males the dorsal mm SL), rather deep-bodied, Apistogramma species lappets are pointed, in females blunt to slightly point - which exhibits marked sexual dimorphism, and which is ed. In adult males the membranes of the anterior half distantly related to both the A. cacatuoides group and of the spinous dorsal are strikingly elongated. the A. trifasciata assemblage. A. arua males can be dis - Membrane length increases from D1 to D4 (the tinguished from all other known members of the genus longest), then decreases again to D8; the remainder by the following characters: a forked tail; extremely elon - of the fin is without any significant elongation of the gate dorsal spine membranes (2) 3 to 5 (7); a broad lon - membranes, and its edge has a slight concave curva - ture. The height of the anterior dorsal (round about gitudinal band extending onto the base of the caudal fin; D4) is equal to body depth, the central portion is rela - large round spots on this band, coinciding with the posi - tively low, about 1/3 of the depth of the section of body tions of the 3rd and 4th vertical bars; (depending on below. The soft dorsal is significantly prolonged and mood) a wedge-shaped, caudally tapering, spot in the pointed, extending back over approximately the first centre of the anterior half of the flank beneath the lon - third of the caudal fin. The anal does not deviate sig - gitudinal band, and three rows of spots of upright half- nificantly from the generic norm. Its soft portion is only moon shape (compare fig. 10, middle right). Females slightly prolonged, extending to about the middle of have a rounded caudal fin, weakly elongated dorsal the non-prolonged area of the caudal. The caudal fin membranes 2 and 3, and a bold lateral spot coinciding in males is forked, with prolongation of rays D3, D4, with the position of the 3rd vertical bar, with an addi - V4, and V3. The intervening region is straight-edged. tional, somewhat fainter, spot on the 4th bar. The extensions represent about 1/3 of the length of the fin. The female paratype has a round to slightly Description truncate caudal, but with a slight pointed prolongation Based largely on examination of the holotype, ampli - of the upper lobe. Ventral relatively short with slightly fied by study of the paratypes and live specimens in the elongate tips in both sexes, extending back to a verti - aquarium. cal through the anal spines. Fin formulae: D XV/6 (1), XV/7 (3); A III/6 (2), III/7 (1) (1 damaged); P I/5 (4). Teeth conical, slender, recurved in the distal third of the jaws, tips reddish or brownish. Head pores as in A. cacatuoides, number not reduced. Pharyngeal region not examined.

Coloration The increase in the number of Apistogramma species known has led to a concomitant increase in the difficul - ties attendant on producing both a meaningful morpho - logical description and a meaningful description of the coloration of preserved material. Accordingly, in describing the new species we will follow the example of various authors (Kullander 1980 & 1986; Koslowski 1985; Linke & Staeck 1995; Römer 1994 & in press; Fig. 3. Map showing the type locality of A. arua. Staeck 1991) in placing particular emphasis on live col - aqua vol. 3 no. 2 - 1998 48 Uwe Römer and Frank Warzel

Apistogramma arua Types latter spot not always visible in all specimens. A distinct black spot on the posterior upper third of the Biometry MZUSP ZFMK ZFMK ZFMK operculum, visible in most, but not all specimens. 18599 18601 18605 Cheek-, snout-, and superorbital-stripe, and dorsal spots, are present as typical for most A. cacatuoides- Sex mf mf complex (compare figs). SL 44.4 34.3 34.5 11.6 Three rows of spots of upright half-moon shape (com - TL 65.1 44.8 # 22.0 pare fig. 10, middle right) are regularly visible in both sexes on the flanks below the lateral band, a pattern HL 14.1 11.4 11.8 6.0 that is regularly found in A. cacatuoides- complex fish. HD 12.2 9.9 10.0 4.6 Depending on mood a wedge-shaped, caudally taper - BD 15.8 12.2 12.3 5.3 ing, spot, formed by these merging spots, is replaces PDL 15.3 12.6 13.2 6.8 the rows on the flanks in the centre of the anterior half PPL 17,1 14,5 # 7.0 of the flank beneath the longitudinal band (Fig. 10 bot - tom left). Depending on mood, the base colour of OD 4.4 4.1 4.2 1.3 females varies from a light coppery grey (neutral mood) SNL 3.1 2.4 2.8 1.1 to a less usual brassy yellow (territorial coloration); in CD 3.9 2.1 2.6 0.8 the latter case the scale edgings fade. Two round later - IOW 4.1 2.4 2.6 1.4 al spots are clearly visible, in territorial and reproductive UJL 3.1 2.1 2.1 1.2 females, on the lateral band, at the locations of vertical bars 3 and 4. LJL 3.6 2.3 2.3 1.6 Unlike females (photograph: page 273 top, Römer in CPD 7.0 5.7 6.0 2.4 press), males exhibit no special broodcare coloration. CPL 5.7 4.3 # 2.0 The base colour of females is golden yellow at all DBL 27.0 20.5 21.0 18.6 stages of brood care. The lateral spot(s), the cheek ABL 8.4 6.1 5.7 3.0 stripe, frontal half of ventrals, margins of dorsal and PeeFL 11.2 9.4 # 4.6 anal fins, and the first two to four membranes of the dorsal fin (compare figs.) become prominent clear PelFL 17.1 13.1 # 4.4 black. The body scales exhibit a narrow coffee-coloured PSL 5.2 5.1 4.7 2.3 edging, producing a reticulated appearance. LDS 6.8 4.2 5.9 2.2 LAS 6.1 4.4 5.2 2.4 Ontogeny of the Colour Pattern The development of the colour pattern was studied in status HT PT PT PT aquarium-reared specimens, documented photograph - ically, and evaluated. Newly free-swimming fry exhibit oration, with the description amplified by illustrative a pattern of irregular dots common to all known material. And because, as mentioned above, ontogenic Apistogramma species at this stage, particularly clear - data are proving of increasing significance in specific ly marked in the region of the lateral spots and the pos - diagnoses, the genesis of the pattern of black markings terior bars. At a length of approximately 1 cm TL the fry, is also covered, based on research using aquarium- when in aggressive mood, already exhibit the species- reared . typical anterior lateral spot. In fry of 2 cm or more TL the spot is regularly clearly Live coloration The live coloration and pattern is mainly shown by the accompanying illustrations in plates 1 to 3 and addi - tionally in Römer (in press). In both sexes the base colour of the body in neutral mood is copper-brown, each scale being edged post- eriorly with dark black-brown. The dorsal fin in males has a narrow red edging. A longitudinal band runs along the flank from the posterior edge of the eye to the position of vertical bar 7 on the caudal peduncle, becoming increasingly broader from front to rear. There is a distinct black spot on the caudal peduncle, some - times connected to the longitudinal band via a narrow stripe. A spot of variable, but mostly squarish, shape in the lateral band in the position of vertical bar 3, and a Fig. 4. Rio Arua at the mouth of the type locality affluent. Photo by slightly smaller one in the position of vertical bar 4, the Frank Warzel

49 aqua vol. 3 no. 2 - 1998 Apistogramma arua sp. n.

Fig. 9

Fig. 10

Fig. 9. Apistogramma arua, sketch of typical male, drawn from photographs of holotype. Drawing by Erika Römer. Fig. 10. Apistogramma arua, table showing 6 different black markings (in diagram form): top right: dominant male, top left: subdominant male, middle right: dominant female, middle left: subdominant female, bottom right: breeding female, bottom left: breeding aggressive female. Drawings by Erika Römer. visible. In normal coloration there are 2-4 rows of black increasingly more distinct, and at a length of more than or dark brown dots, a feature found otherwise only in 1 cm TL begin to merge on the anterior third of the members of the A. cacatuoides group. These rows of flank, gradually forming the species-typical wedge- dots are commonly seen in fry as early as 14 days from shaped spot. At the age of about 3months the final free-swimming. With increasing body size they become stage of the development of the colour pattern is aqua vol. 3 no. 2 - 1998 50 Uwe Römer and Frank Warzel reached, and the fry now exhibit for the first time a few other, unidentified, small Characidae in the bank stripe between the operculum and the anterior anal zone and the open water. insertion, similar to that seen in A. trifasciata. A further tiny stream near the type locality, with deposits of red-brown sediment in places, was investi - Coloration in Preserved Specimens gated, but no A. arua were located, although here too a Based largely on the holotype. The base coloration of few individual Aequidens cf epae were found. preserved specimens differs little from that of live ani - mals. The base colour changes to more yellowish-grey Etymology after some months of preservation. The pattern of black The specific name arua refers to the type locality and markings as in live specimens. is a noun in apposition.

Distribution Differential Diagnosis and Discussion To date A. arua is known only from the type locality, In describing any new Apistogramma species with a which, at the time of collection, was accessible only by forked caudal fin, it is first necessary to test for identity a half hour foot-march, as access by river is prevented with A. sweglesi Meinken, 1961. Because the type by a waterfall several metres high. The species may be material of this latter species has been destroyed restricted to the upper course of the Rio Arapiuns; at (Römer, in press), the comparison must be made on any rate several subsequent expeditions have failed to the basis of data given in the original description. Iden - find it downstream of the waterfall-like cachoeira tity of A. arua with this species can easily be ruled out (rapids). Further exhaustive investigations of the region on the basis of the different form of the dorsal as well have so far failed to clarify the extent of the distribution as the completely different pattern of markings on the of the species. flanks. On the basis of morphology and markings, A. arua can be confused with only a few members of Ecology the A. cacatuoides complex, namely A. cacatuoides, The type locality of A. arua lies in dense primary for - A. juruensis, A. luelingi, and A. staecki from the est, such that the igarapé is in full shade. A. cacatuoides sub-complex (Römer & Soares 1995 a At the collection site a small right-bank forest stream & b, 1996 a-c), as well as with forms belonging to the enters the Rio Arua, which at this point is some 30-40 A. gibbiceps group, which, in the view of one of the metres wide. The mouth of the igarapé is in turn about authors (UR) at present includes, as well as A. gibbi - 2 metres wide, but by about 50 metres upstream nar - ceps, A. brevis, A. personata, and A. sp. "Breitbinden". rows to 1.5 metres with a depth of 10-60 cm and a Especially striking, and of particular diagnostic value, is markedly strong current. The water was clear (under - the highly variable, mood-dependent, sometimes water visibility about 4 metres) with only a faint tinge of wedge-shaped flank marking, which does not occur to yellow (undoubtedly due to dissolved organic material). any comparable extent in any previously-described The substrate consisted of fine sand, covered by a Apistogramma species. This flank marking, which thick layer of loose sediment in the calmer bank regions sometimes consists of 2 or 3 longitudinal series of large and bays. No submersed vegetation was evident. In the spots, not clearly delineated and merging into each calm water of shallow bays there were extensive other, exhibits clear similarities to those seen in the deposits of leaf litter. The open water was commonly species of the A. cacatuoides sub-complex, in partic- less than 15 cm deep, but in places measured up to ular A. cacatuoides itself. In addition the shape of the about 50 cm from surface to top of substrate. body and tail, the presence of spots on the back, the As is typical of Apistogramma in general, A. arua cheek stripe, the longitudinal band, and the caudal remains close to the substrate, above the leaf litter, in peduncle spot, are all in accord. But A. arua can with calm shallow water. The population density was appar - certainty be distinguished from A. cacatuoides and ently relatively low, as only 11 specimens were collect - A. luelingi in that it never has spots in the dorsal or cau - ed during a 2 hour period, with effectively equal num - dal; moreover A. luelingi has a narrower longitudinal bers of each sex - 6 males and 5 females. Some of the band. In A. juruensis the peduncular spot is clearly sep - females captured were in broodcare coloration. In view arated from the longitudinal band, and the head is of the not inconsiderable size variation between the appreciably more massive in comparison to that of A. individual specimens, it is reasonable to assume that arua. Like A. steindachneri (Regan, 1906), A. staecki, breeding extends over a long period. when in aggressive mood, exhibits a pattern of vertical Other found in the biotope included young of bars on the caudal peduncle, absent in A. arua. The the cichlids Aequidens cf epae and Crenicichla sp. species of the A. gibbiceps group (as listed above) have (saxatilis group), found in the bank zone, plus two a quite different pattern on the lower part of the flanks, species of Corydoras catfish which were resident in as well as various differences in the details of the dor - both the bank region and the transition zone between it sal fin, longitudinal band, and the peduncular spot. and the leaf litter. The latter also contained The markings on the sides of A. arua can vary con - Microcharacidium cf weitzmani, and there were also a siderably according to mood: during courtship or brood

51 aqua vol. 3 no. 2 - 1998 Apistogramma arua sp. n.

Fig. 5. Apistogramma arua, live half-grown holotype, dominant, Fig. 6. Apistogramma arua, same as fig. 3, but in neutral mood. in fright coloration, eating a juvenile A. spec. "Pimentel"; note Photo by Frank Warzel the still round shape of the caudal fin. Photo by Frank Warzel

Fig. 15. Apistogramma trifasciata, male (for comparison). Photo Fig. 16. Apistogramma maciliensis, male (for comparison). by Uwe Römer Photo by Uwe Römer

Fig. 17 . Apistogramma juruensis, male (for comparison). Fig. 18. Apistogramma luelingi, male (for comparison). Photo by Photo by Uwe Römer Uwe Römer

Fig. 18. Apistogramma sp."Breitbinden", male (for comparison). Fig. 19. Apistogramma personata, holotype male Photo by Uwe Römer. (for comparison). Photo by Uwe Römer aqua vol. 3 no. 2 - 1998 52 Uwe Römer and Frank Warzel

-care the longitudinal bands are reduced and a stripe The growth rate of the fry is relatively slow, and only appears running from the posterior edge of the eye to after about 4 months do they attain a length of 2 cm the anterior edge of the anal fin; A. trifasciata is the only (TL). At this size they are driven from the territory by other species to exhibit anything similar. The degree both parents, although the aggression level is low. of elongation of the dorsal fin membranes exhibits Thereafter only the one or two youngsters are tolerated some parallels with that seen in A. cacatuoides and in the parental territory. At the age of 6-7 months the A. maciliensis. There is also a certain similarity to the young fish spawn for the first time. latter form in the presence of a red spot in the region of A. arua is one of the least productive members of the the lower posterior edge of the operculum. Just one genus, with 50 fry per brood to be regarded as a very other species, A. sp."Breitbinden", exhibits a spot of this good result. kind, but in that species the spot is on the skin of the throat and displayed only during threat behaviour, while Acknowledgments in A. maciliensis it lies on the edge of the operculum, FW would like to thank Axel Krüger, Marco Loew, and and in A. arua on the body, between the edge of the Rainer Zgorniak for their support during the 1995 col - operculum and the pectoral and pelvic insertions. lecting trip. UR would like to thank Dr Klaus Busse The ontogenesis of the flank markings exhibits simi - (ZFMK), Dr Friedhelm Krupp (SMF) and Dr. Georges larities to that seen in A. trifasciata. Lenglet (IRSNB) who were so kind as to make possible At the present time A. arua has to be regarded as the investigation of the type material, Erika Römer for incertae sedis within the genus as it is currently not preparing the drawings and tables, as well as Mary Bai - possible to draw any definite conclusions about its ley, Ingo Hahn, Dr Wolfgang Staeck and two anony - systematic position of A. arua. This has to be post - mous reviewers for reading and constructively criticis - poned to an additional forthcoming study. But we can ing earlier versions of the manuscript. We would also nevertheless speculate here that it may be linked to the like to specially thank Heiko Bleher and the aqua team, A. cacatuoides complex as well as to the A. trifasciata who kindly undertook to translate and publish the man - group. uscript at short notice.

Aquarium biology To date very little has been published on the aquarium References biology of this species. At present, therefore, our data are based upon the observations of the authors, sup - Ahl, E. (1931): Neue Süßwasserfische aus dem plemented by the personal communications of Loew. Stromgebiet des Amazonasstromes. Sitzungsberichte A. arua has proved particularly delicate as regards der Gesellschaft naturforschender Freunde Berlin: aquarium maintenance. Clean, very soft, slightly acid 206 - 211. (humic) water is essential in order to maintain this Eigenmann, C. H. (1912): The freshwater fishes of species successfully, let alone breed it. Breeding can British Guiana, including a study of the ecological be achieved only if natural water parameters - soft and grouping of species and the relation of the fauna of very acid - are supplied. Because these fishes are gen - the plateau to that of the lowlands. Memoirs of the erally extremely timid, the aquarium should be provid - Carnegie Museum Vol. V (67) 578 pp. ed with numerous hiding-places, and in addition it is Eigenmann, C. H. & C. H. Kennedy (1903): On a Col - advisable to keep them together with "dither fish", such lection of Fishes from Paraguay, with a Synopsis of the as members of the smaller Rivulus species. American Genera of Cichlids. Proceedings of the Males are polygamous and will tolerate up to about 10 Academie of Natural Sciences of Philadelphia 59: 533. females in their relatively large territories, breeding with Géry, J. & Römer, U. (1997): Tucanoichthys tucano them in succession. If kept in pairs, A. arua is relatively gen. n. sp. n., a new miniature characid fish (Teleostei: peaceful towards its partner. The brood care follows the Characiformes: Characidae) from the Rio Uaupés pattern known from other Apistogramma species: the basin in Brazil. aqua Journal of Ichthyology and female alone tends the eggs and fry, while the male Aquatic Biology 2 (4): 65 - 72 (incl. 5 figure on cover stands guard, defending the territory against intruders. page 1 & 4) At about 28°C the egg phase lasts barely 2 days, the Haseman, J. D. (1911): An annotated Catalog of the larval stage a further 5-6 days. To date males have not Cichlid Fishes collected by the Expedition of the played any active part in brood care; after the fry have Carnegie Museum to Central South America, 1907 - become free-swimming it is the mother that leads the 1910. Annals of the Carnegie Museum VII: 329 - 373. brood around in a close-packed shoal, for up to 2 Hoedeman, J. J. (1951): Notes on the Fishes of the months. From the first day of free-swimming the fry are Cichlid Family I: Apistogramma cacatuoides sp. n. able to take Artemia nauplii, even though they are rela - Beaufortia - Series of Miscellanious Publications 4: tively small by Apistogramma standards. Not until the 1 - 4. fry are 4-6 weeks old, the point at which the female Koslowski, I. (1985a): Descriptions of new species of usually spawns again, does the male shepherd them. Apistogramma (Teleostei: Cichlidae) from the Rio

53 aqua vol. 3 no. 2 - 1998 Apistogramma arua sp. n.

Mamoré system in Bolivia. Bonner Zoologische Aquatic Biology 1 (1): 1 - 12. Beiträge 36 (1/2): 145 - 162. Römer, U. (1997): Diagnoses of two new dwarf cichlids Koslowski, I. (1985b): Die Buntbarsche der neuen Welt (Teleostei; Perciformes) from Peru, Apistogramma - Zwergcichliden. Essen; Reimar-Hobbing GmbH, 192 atahualpa and Apistogramma panduro spp. n. Bunt - pp. barsche Bulletin 182 (October 1997): 9 - 14. Kullander, S. O. (1976): Scientific Results of the Peru- Römer, U. (in press): Cichliden I: Naturgeschichte der Bolivia Expedition Dr. K. H. Lüling 1966: Apistogram - Zwergbuntbarsche Südamerikas. 1st german ed.; ma luelingi sp. n., a new cichlid fish from Bolivia Mergus, Melle. 1311 pp. (Teleostei: Cichlidae). Bonner Zoologische Beiträge Römer, U. (in press): Cichlid Atlas I: Natural History of 27 (3/4): 258 - 266. the Neotropical Dwarf Cichlids. 1st engl. ed.; Mergus, Kullander, S. O. (1979): Description of a new species Melle. 1311 pp. of the genus Apistogramma (Teleostei, Perciformes, Römer, U. & D. Soares (1995a): Remarks on Api- Cichlidae) from Peru. Revue Suisse de Zoologie stogramma juruensis Kullander 1986. Cichlid News 4 (Genève) 86 (4): 937 - 945. (4): 12 - 16. Kullander, S. O. (1980a): A Taxonomical Study of the Römer, U. & D. Soares (1995b): Apistogramma Genus Apistogramma Regan, with a Revision of juruensis Kullander 1986. Cichlidae Communique - Brazilian and Peruvian Species (Teleostei: Percoidei: The Journal of the Pacific Coast Cichlid Association Cichlidae). Bonner Zoologische Monographien 14: #92 (10/11): 1 - 5. 152 pp. Römer, U. & D. Soare (1996a): Ein aquaristisch neuer Kullander, S. O. (1980b): A redescription of the South Zwergbuntbarsch: Apistogramma juruensis. Die American cichlid fish Papiliochromis ramirezi (Myers Aquarien- und Terrarien Zeitschrift (DATZ) 49 (6): 350 & Harry, 1948). Studies on Neotropical Fauna and - 355. Environment 15: 91 - 108. Römer, U. & D. Soare (1996b): Apistogramma juruen - Kullander, S. O. (1986): Cichlid Fishes from the Ama - sis Kullander, 1986: Beobachtungen zur Aquarienbi - zon River Drainage of Peru. Stockholm; Swedish ologie eines neu eingeführten Zwergbuntbarsches. Museum of Natural History, 431 pp. Aquarium Heute 14 (3): 356 - 359. Kullander, S. O. & W. Staeck (1988): Description of a Römer, U. & D. Soare (1996c): Apistogramma juruen - new Apistogramma species (Teleostei, Cichlidae) sis. The Apisto-Gram - Quarterly Journal of the Apis - from the Rio Negro in Brazil. Cybium 12 (3) 189 - 201. togramma Study Group Vol. 11 / No. 3 / Issue #48 Linke, H. & W. Staeck (1992): Amerikanische Cichliden (September 1995): 13 - 16 I - Kleine Buntbarsche. 4. ed.; Melle; Tetra-Verlag, 232 Seidel, C. (1997): „Neue“ Apistogramma -Art? Die pp. Aquarien- und Terrarien Zeitschrift (DATZ) 50 (4): 213 Linke, H. & W. Staeck (1995): Amerikanische Cichliden Staeck, W. (1991): Eine neue Apistogramma -Art I - Kleine Buntbarsche. 5. ed.; Melle; Tetra-Verlag, 232 (Teleostei: Cichlidae) aus dem peruanischen Ama - pp. zonasgebiet. Ichthyoogical Exploration of Freshwaters Meinken, H. (1961): Mitteilungen der Fischbestim - 2 (2): 139 - 149. mungsstelle des VDA XXXVII: Drei neu eingeführte Stawinkowski, R. (1997): Rio Arapiuns: Ein Fluß und Apistogramma -Arten aus Peru, eine davon wis - seine Cichliden (Teil 2). DCG-Informationen 28 (3): 53 senschaftlich neu. Die Aquarien- und Terrarien - 58. Zeitschrift (DATZ) 14 (5): 135 - 139. Steindachner, F. (1875): Beiträge zur Kenntnis der Meinken, H. (1969): Apistogramma gibbiceps n. sp. Chromiden des Amazonasstromes. Sitzungsberichte aus Brasilien (Pisces, Teleostei, Cichlidae). Sencken - der Kaiserlichen Akademie der Wissenschaften Wien bergiana biologica 50 (1/2): 91 - 96. LXXI (i): 111 - 115. Pellegrin, J. (1936): Un poisson d´Aquarium nouveau du genre Apistogramma. Bulletin de Societé national d´Acclimation de France: Protection de Nature 83: 56 - 58. Regan, C. T. (1906): LX. Descriptions of a new cichlid fish of the genus Heterogramma from Demerara. Annals and Magazine of Natural History I (8) (97): 370 - 371. Römer, U. (1993): Erste Ergebnisse von Untersuchun - gen an Apistogramma elizabethae KULLANDER, 1980. in: Buntbarschjahrbuch 2 (1994): 68 - 73. Römer, U. (1994): Apistogramma mendezi sp. n. (Teleostei: Perciformes; Cichlidae): Description of a New Dwarf Cichlid from the Rio Negro System, Ama - zonas State, Brazil. aqua Journal of Ichthyology and aqua vol. 3 no. 2 - 1998 54