Auchenipterichthys longimanus ( Günther, 1864 )

Ferraris Jr, Carl J., Vari, Richard P. & Raredon, Sandra J., 2005, Catfishes of the genus Auchenipterichthys (Osteichthyes: Siluriformes: Auchenipteridae); a revisionary study, Neotropical Ichthyology 3 (1), pp. 89-106 : 95-98

Auchenipterichthys longimanus ( Günther, 1864) Figs. 1 , 5-7

Auchenipterus longimanus Günther, 1864: 195 [type locality: River Capin (= rio Capim), Para ( Brazil); Syntypes: BMNH 1849.11 .8.11 (3), possibly ZMB 5059 (1)].

Auchenipterichthys longimanus, Eigenmann & Eigenmann, 1888: 154 [Manes (=Maués), rio Madeira; Cameta]. – Eigenmann & Eigenmann, 1890: 284 [redescription based on specimens from Maués, rio Madeira and Cameta]. – Eigenmann & Eigenmann, 1891: 34 [in listing of fresh water fishes of South America; distribution cited as southern tributaries ofAmazon]. – Eigenmann, 1910: 396 [southern tributaries of the Amazon]. –Miranda-Ribeiro, 1911: 372 [description and distribution information based on Günther, 1864, and Eigenmann & Eigenmann, 1891]. – Gosline, 1945: 13 [literature summary; tributaries of Amazon]. – Fowler, 1951: 458 [literature summary]. –Merona, 1987: 122 [ Brazil, lower rio Tocantins]. – Ferreira, 1995: 52 [ Brazil, Pará, rio Trombetas].– Taphorn et al., 1997: 83 [ Venezuela]. – Ferraris, 2003: 472 [checklist]. – Lasso et al., 2003 a:240 [checklist, Caura River, Venezuela]. – Lasso et al., 2003 b:285 [checklist, Caura River, Venezuela]. – Rodríguez-Olarte et al., 2003: 199 [checklist, Lower Caura River, Venezuela].

Auchenipterichthys thoracatus (not of Kner, 1857), Fisher, 1917: 424 [specimen from Manáos (=Manaus, Brazil)]. – Mees, 1974: 38 [ Fisher (1917) record of species from Manaus corrected].

Trachycorystes obscurus (not of Günther, 1863), Steindachner, 1915: 80 [misidentification, see Mees, 1974: 36, 38; Brazil, mouth of rio Negro].

Auchenipterichthys longinmanus, Merona et al., 2001: 389 [ Brazil, rio Tocantins; stomach contents analysis; species name misspelled].

Diagnosis. A species of Auchenipterichthys with coracoid bone covered with thick integument and not exposed ventrally ( Fig. 1c ), an emarginate or truncate caudal-fin margin, 25 or fewer branched anal-fin rays (modally 21; Table 1), nine (rarely eight) branched pelvic-fin rays ( Table 1), the anterior teeth on premaxilla not visible when the mouth is closed, and the body pigmentation pattern not consisting of distinct dark spots on a gray background. Auchenipterichthys longimanus is most similar in appearance to A. punctatus , which differs from A. longimanus primarily in having dark spots that cover much of dorsolateral surface of the body. The possession of a coracoid bone that is not exposed ventrally ( Fig. 1c ), the anterior teeth on the premaxilla that are not visible when the mouth is closed, and nine (rarely eight) branched pelvic-fin rays ( Table 1) distinguishes A. longimanus from its other two congeners, A. coracoideus and A. thoracatus , which have coracoids that are exposed ventrally ( Figs. 1 a-b) rather than covered by a thick layer of integument, the anterior teeth on the premaxilla visible when mouth is closed and, typically eight branched pelvic-fin rays.

Description. Body depth at dorsal-fin origin 0.22–0.25 of SL and equal to, or slightly greater than, body width at cleithrum. Body depth at anal-fin origin 0.25–0.27 of SL and nearly equal to HL. Body compressed, with width at anal-fin origin approximately 0.48–0.51 of body depth at that point. Ventral surface of coracoids not exposed on ventral surface of body (see Fig. 1c ). Lateral line complete and midlateral. Canal having irregular zigzag pattern, with oblique posteriorly-directed branches off main canal. Lateral line canal extending short distance onto, and directed posteriorly or obliquelyposterodorsally on, caudal-fin base.

Head depressed anteriorly; depth of head at vertical through middle of orbit greater than distance from middle of eye to dorsal midline of head. Head length 0.25–0.27 of SL. Dorsal profile of head broadly convex anteriorly and then straight or very slightly convex from vertical running through anterior margin of orbit posteriorly as far as dorsal-fin origin. Distance from midpoint of snout to anterior margin of orbit approximately 1.5 times horizontal diameter of orbit. Snout margin broadly rounded from dorsal view. Interorbital width approximately 0.65–0.68 of HL and approximately equal to distance from middle of eye to posterior margin of opercle. Eye large, lateral, and visible in both dorsal and ventral views. Orbit distinctly ovoid with horizontal axis longer.

Barbels slender and thread-like. Maxillary barbel very long, extending posteriorly nearly to posterior tip of cleithral spine. Medial mandibular barbel originating immediately posterior of lower lip; adpressed barbel extending posteriorly to point slightly short of vertical through transverse plane through origin of lateral mandibular barbel. Lateral mandibular barbel originating in plane slightly anterior of vertical through middle of orbit and extending posteriorly approximately to transverse line through pectoral-spine origin.

Branchiostegal membrane broadly attached to isthmus; ventral margin of gill opening extending to vertical approximately one orbit length posterior of rear margin of orbit.

Mouth terminal. Anterior teeth on premaxilla not visible from ventral view when mouth closed. Teeth on premaxilla minute and arranged in band. Band consisting of approximately eight irregular series of teeth at symphysis and of ten irregular series laterally. Dentary teeth slightly larger than those on premaxilla, with approximately six series of teeth at symphysis that decrease to one tooth row posterolaterally.

Dorsal-fin origin at 0.31–0.34 of SL. Length of dorsal-fin base slightly less than one-half length of first branched dorsal-fin ray. Dorsal-fin spine pungent, with slightly curved, convex anterior margin. Length of dorsal-fin spine approximately equal to distance between anterior nares and posterior margin of opercle, without elongation apparent in examined mature males. Anterior surface of dorsal-fin spine with single series of relatively well-developed, antrorse serrae extending nearly to tip of spine. Posterior margin of spine with medial row of retrorse serrae extending nearly to tip of spine. Serrae on posterior surface of spine shorter than those on anterior surface in juveniles and females; posterior serrae on distal portion of spine proportionally longer in mature males. Dorsal-fin rays II,6. Adipose fin relatively small.

Caudal fin emarginate to obliquely truncate, with dorsal lobe longer than ventral lobe. Principal caudal-fin rays i,7,8,i.

Anal-fin base approximately 0.22–0.24 of SL and slightly shorter than HL. Anal-fin origin located distinctly posterior of middle of SL and slightly posterior of middle of TL. Analfin margin straight, with first ray longest and subsequent rays becoming progressively shorter, but with anterior rays in mature males extending slightly beyond margin of rest of fin. Last anal-fin ray without membranous attachment to caudal peduncle. Anal-fin rays typically iii,18 to iii,23 (iii, 25 in one of 87 specimens; Table 1).

Distal margin of pelvic fin broadly convex, with third branched ray longest. Pelvic-fin insertion slightly posterior of middle of SL. Tip of adpressed pelvic fin barely reaching anal-fin origin. Pelvic-fin rays typically i,9, rarely i,8 ( Table 1).

Pectoral fin with strong spine serrated along entire length of both margins with antrorse serrae along anterior margin and retrorse serrae along posterior margin. Anterior pectoral-fin rays longest. Fin margin straight anteriorly and convex along posterior rays. Pectoral-fin rays I,7, or I,8, rarely I,9 ( Table 1).

Pigmentation pattern in alcohol. Overall ground coloration ranging from light to dark brown, with overall ground coloration darker on dorsal portion of head and body and in some individuals on midlateral portion of body posterior of head in region overlying swimbladder. Abdomen unpigmented. Snout and upper lip darkly pigmented to some degree in all specimens. Lower lip with curved patch of dark coloration along margin in more darkly pigmented individuals.

Lateral surface of body with small, unpigmented, rounded spots of approximately one-fifth width of pupil or sometimes smaller. Number and distribution of unpigmented spots varies greatly in different population samples, with spots and their arrangement difficult to discern in some individuals, particularly those of fainter overall coloration. Unpigmented spots in some individuals form variably-developed row or sometimes narrow band along midlateral region of body from rear of head to hypural joint, but with anterior and posterior portions of such row or band variably present in different specimens. Individual spots or series of vertically-aligned spots present on dorsolateral portion of body in region from vertical through base of rear of dorsal fin, or posterior of that point, to area under base of adipose fin. Some specimens, often those with very dark overall pigmentation, with individual spots or series of vertically-aligned spots present on dorsolateral portion of body from vertical through base of rear of dorsal fin, or posterior of that point, to area under base of adipose fin. Number of such unpigmented spots highly variable in different specimens, with spots nearly completely absent in some individuals.

Dorsal fin with dark pigmentation on distal portion of first (lightly pigmented individuals) or first and second (more darkly pigmented individuals) interradial membranes. Adipose fin dusky to dark. Caudal fin ranges from dusky basally and lighter posteriorly to dark overall with little decrease in degree of pigmentation posteriorly. Some specimens with small white spots within dark, basal pigmentation field in region overlying central rays. Anal fin with variably developed dark pigmentation basally. Such pigmentation more obvious in overall more darkly pigmented individuals. Dorsal surface of pelvic fin hyaline or with diffuse field of small, dark chromatophores in darker individuals with chromatophores not, however, forming distinct spot. Margins and sometimes dorsal surface of pectoral-fin spine dark; interradial membranes with diffuse fields of small, dark chromatophores.

Maxillary and mandibular barbels typically hyaline, but with few small, dark chromatophores present in overall darkly pigmented individuals.

Sexual dimorphism. Although a number of mature males of 126 to 140 mm SL (as indicated by the possession of an elongated urogenital tube adhering to the anterior margin of the anal fin) were examined, none demonstrated an elongation of the dorsal-fin spine beyond the condition present in females of comparable sizes. It is uncertain whether this observation reflects the absence of sexual dimorphism in the species or the lack of nuptial males in the available samples. Serrae on the posterior surface of the distal one-half of the dorsal-fin spine are proportionally longer in mature males than they are in juveniles and females.

Distribution. Orinoco River basin in Venezuela, lower and middle portions of Amazon and Tocantins Rivers in Brazil ( Fig. 7 ).

Biology. Merona et al. (2001: 389) report that Auchenipterichthys longinmanus (sic) in the lower portions of the Tocantins River, feeds primarily on terrestrial invertebrates (81.88 % of diet) and also decapods (10.94%) and aquatic invertebrates (7.19%).

Remarks. The catalog number for the syntype series of Auchenipterus longimanus, BMNH 1849.11.8.11, was misreported in Eschmeyer (1998: 931) as BMNH 1849.121.8.? and BMNH 1849.11.8.?, and in Ferraris (2003: 472) as BMNH 1849.121.8.11. The original description indicated that the description was based on “fine specimens”; however the BMNH register provides no further information as to the number of specimens actually examined by Günther. Three specimens are currently found in the syntype lot (BMNH 1849.11.8.11). Eschmeyer (1998: 981) cited a specimen from ZMB as a syntype of this species, without comment except that the specimen was from BMNH. We have not investigated further to see if there is justification for labeling the ZMB specimen as part of the type series.

Material examined. BRAZIL. Amazonas: Alto rio Negro , at mouth of igarapé do Ibará, MZUSP 31094 , 1 (135) ; MZUSP 52104 , 14 (135–167) . rio Daraá, Cachoeira do Aracu (1°40’S, 64°40’W), MZUSP 52097 , 10 (127–173) ; MZUSP 59039 , 1 (146) . Rio Negro, São Gabriel da Cachoeira , MZUSP 52098 , 7 (131–144) . Rio Negro , Anavilhanas (2°40’S, 60°40’W), MZUSP 52099 , 10 (94-140) ; MZUSP 52102 , 1 (126) ; MZUSP 59036 , 2 (123–136) ; MZUSP 59037 , 1 (107) . Rio Negro, Ilha Mari-Mari , MZUSP 52100 , 3 (126–146) ; MZUSP 59040 , 1 (153) . Blackwater igapó at confluence of rio Cuiuni and rio Negro (0°40’S, 63°10’W), MZUSP 52101 , 8 (117–162) . Blackwater igapó at confluence of rio Marauiá and rio Negro (approximately 0°20’S, 65°20’W), MZUSP 52103 , 23 (137–182) . rio Arirará , near its mouth (0°30’S, 63°35’W), MZUSP 31078 , 2 (124–131) . Rio Negro , 6.5 km below Jufari (1°17’37"S, 61°56' 57"W), MZUSP 55909 , 1 (50) . Igarapé Jaraqui, left bank of rio Negro , above Manaus (latter locality at 3°06’47"S, 60°01’30"W), MZUSP 6206 , 12 (116–141) . Rio Negro above Manaus (latter locality at 3°06’47"S, 60°01’30"W), MZUSP 6161 , 4 (124–137) . Manaos (= Manaus, 3°06’47"S, 60°01’30"W), FMNH 57799 , 1 (129; formerly CM 6782 ) . Rio Negro , Anavilhanas, igapó, MZUSP 63298 , 1 (123) . Rio Maués at Maués (3°22’S, 57°38’W), MCZ 7374 , 1 (54) . Lago Saracá (2°52’S, 58°22’W), MZUSP 5814 , 2 (114–118) . Igarapé of rio Maraú (3°24’S, 57°42’W), MZUSP 7300 , 2 (115–119) . Rio Preto da Eva , near Manaus (2°46’S, 59°10’W), MZUSP 57104 , 13 (108–137) . Lago Puraquequara, mouth of rio Puraquequara (2°56’S, 59°49’W), MZUSP 6104 , 16 (139–167) . Rio Tefé , Supi?- Pucu (approximately 3°40’S, 65°50’W), MZUSP 52074 , 1 (145) . Pará: rio Xingu , edge of river channel (3°10' S, 51°50’W), MZUSP 52096 , 86 (109–162) . Rio Xingu , Belo Monte (3°10' S, 51°50’W), MZUSP 59043 , 2 (124–129) . Beach near mouth of lago Jacaré, Reserva Biológica de Trombetas, rio Trombetas (approximately 1°11’S, 56°40’W), MZUSP 15827 , 2 (135-143) . Lago do Comprido (opposite mouth of lago Leonardo), Reserva Biológica de Trombetas, rio Trombetas (approximately 1°11’S, 56°40’W), MZUSP 15913-15915 , 3 (133-146) . rio Trombetas , MZUSP 5475 , 3 (92–132) . Rio Trombetas , Cuminá, river margin (1°21’20"S, 56°00’W), MZUSP 57108 , 3 (116–136) . Island at the mouth of lago do Erepecu, Reserva Biológica de Trombetas, rio Trombetas (approximately 1°11’S, 56°40’W), MZUSP 15969 , 1 (33) . Rio Trombetas , 20 km above the mouth, shore of the river (1°40’S, 56°00’W), MZUSP 59061 , 1 (128) . Rio Capin (= rio Capim ), BMNH 1849.11 . 8.11, 3 (110–140; syntypes of Auchenipterus longimanus ). Rio Capim, Praia de Caranandéua , MZUSP 57103 , 3 (104–134) . Rio Capim , Vila Santana, MZUSP 57109 , 16 (118–135) ; FMNH 95542 , 2 (115– 118) ; ROM 37954, 2 (120–129) . Rio Capim , MZUSP 57106 , 1 (124) . Igarapé Pacuí, km 97 on highway between Belém and Brasília , MZUSP 57107 , 1 (124) . Paraná Samuuma, mouth of rio Tocantins, MZUSP 57105 , 2 (110–126) . Rio Tapajós (3°35’S, 55°20’W), MZUSP 57102 , 3 (129–132) . Rio Tapajós , between Itaituba and São Luís, shore of river (4°27’S, 56°15’W), MZUSP 63301 , 1 (136) . Município de Cametá , Cametá, rio Tocantins (2°14’S, 49°30’W), MCZ 8158 , 1 (140) . Mato Grosso: rio Aripuanã, upstream of Porto de Balsa, road joining Distrito de Colniza to Panelas, km 18 (9°34’45"S, 59°25’19"W), MZUSP 60387 , 1 (89) . VENEZUELA. Amazonas: Río Orinoco , Kiratare, SU 58754 , 1 (69) . Rocks and rapids in Río Orinoco at Isla Cupaven, FMNH 103482 , 28 (32–65) . Caño Guasuriapana at Guasuriapana; caño and backwater approximately 7 minutes from San Fernando de Atabapo, tributary of río Atabapo (4°00’N, 67°42’W), FMNH 105177 , 2 (74–76) . Río Atabapo, at San Fernando de Atabapo (4°02’N, 67°42’W), MCNG 22361 , 2 (43–44) . Río Mavaca , at base camp, AMNH 91384 , 2 (107–118) . Río Emoni, approximately 2 km upriver from its mouth, Río Siapa basin, Caño Emoni (2°07’N, 66°20’W), MCNG 12308 , 1 (77) . Río Manipitare, approximately 5 to 8 km by water above its confluence with río Siapa , MCNG 38209 , 10 (66–83) . Backwater of río Orinoco behind sand playa approximately 0.5 hr upstream from Isla Tremblador (3°04’N, 66°28’W), ANSP 165794 , 1 (117) . Caño Pozo Azul, río Orinoco drainage (5°45’49"N, 67°29’21"W), INHS , 61570, 8 (60–119). Anzoategui: río Orinoco basin, Soledad, lago Terecaya (8°11’30"N, 63°27’20"W), ANSP 166377 , 1 (66) . Apure: caño La Pica, río Orinoco drainage, approximately 75 km N of Puerto Paez on road to San Fernando (6°53’28"N, 67°30’46"W), AUM 22446, 1 (44) . Caño Potrerito, río Orinoco drainage, approximately 15 km N of Puerto Paez on road to San Fernando (6°24’43"N, 67°31’55"W), AUM 22624, 1 (106) . Río Claro, río Orinoco drainage, 102 road kms N of Puerto Paez on road to San Fernando (7°09’08"N, 67°38’06"W), AUM 224494 , 5 (50–95) . Río Capanaparo, backwater lagoon at mouth of caño Las Varitas, near San Fernando de Apure to Puerto Paez Highway (7°02’N, 67°25’W), ANSP 165494 , 1 (92) . Bolivar: río Orinoco , caño de Quiribana near Caicara (approximately 7°38’44"N, 66°10’23"W), SU 58687 , 2 (57–59) . Río Chaviripa, río Orinoco drainage, on Caicara to Puerto Ayacucho road (7°07’57"N, 66°29’56"W), AUM 22290, 1 (65) . Confluence of río Orinoco and río Caura (7°38’36"N, 64°50’00"W), ANSP 160362 , 1 (54) . Small stream crossing Caicara to Puerto Ayacucho Highway 18 km N of Maniapure (latter locality at 7°11’59"N, 66°31’59"W), ANSP 160824 , 1 (75) . Río Caura , E side of ferry crossing on Caicara to Ciudad Bolivar Highway (7°27’00"N, 65°12’00"W), ANSP 160990 , 11 (35–114) . Guarico: Hato San Jose del Aguaro, río Aguaro (7°46’59"N, 66°24’59"W), UF 36170 , 2 (61–68) . Parque Nacional Aguaro- Guariquito, río Aguas Muertas (8°06’30"N, 66°40’19"W), MCNG 31766 , 8 (49–85) . Río San Bartolo ( río Guariquito-río Orinoco drainage) at Bartolena Ranch (7°59’20"N, 66°39’00"W), INHS 61930 , 1 (45) . Río Bartolo (río Orinoco drainage), Parque Nacional Aguaro-Guariquito, río Aguas Muertas (8°06’30"N, 66°40’19"W), INHS 34874 , 7 (48–112) . Río Bartolo (río Orinoco drainage), Parque Nacional Aguaro- Guariquito, río Aguas Muertas (8°08’01"N, 66°40’53"W), INHS 34076 , 2 (48–94) . Río Bartolo (río Orinoco drainage), Parque Nacional Aguaro-Guariquito, río Aguas Muertas (8°04’14"N, 66°40’50"W), INHS 34499 , 10 (50–87).

Figures

Fig. 1. Ventral view of anterior portion of body of (A) Auchenipterichthys coracoideus, ANSP 178446, 94 mm SL; (B) A. thoracatus, FMNH 57798, 89 mm SL; and (C) A. longimanus, INHS 61570, 67 mm SL; showing different degrees of exposure of coracoid in that region. Line points to exposed coracoids.

Fig. 5. Map of central and northern South America showing distribution of Auchenipterichthys coracoideus (1 = holotype locality; some symbols represent more than one locality or lot of specimens).

Fig. 6. Auchenipterichthys longimanus, INHS 61570, 67 mm SL; Venezuela,Amazonas, caño Pozo Azul, río Orinoco drainage (5°45’49"N, 67°29’21"W).

Fig. 7. Map of central and northern South America showing distribution of Auchenipterichthys longimanus (1 = holotype locality; some symbols represent more than one locality or lot of specimens).