Auchenipterichthys punctatus (Valenciennes, 1840)

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 : 99-101

Auchenipterichthys punctatus (Valenciennes, 1840) Figs. 8-10

Auchenipterus punctatus Valenciennes , in Cuvier & Valenciennes, 1840: 219 (163 in Strasbourg deluxe edition); [type locality: probably Brazil (translated from original description); holotype: MNHN b-0216]. – Royero & Hureau, 1996: 374, fig. 3 [comments on holotype and transfer to Auchenipterichthys ].

Auchenipterichthys dantei Soares-Porto, 1994: 282 , fig. 3 [type locality: Brazil, Amazonas , Paricatuba, rio Negro (3 o 07’S, 60 o 26’W); holotype: MZUSP 43332 ].

Auchenipterichthys punctatus, Royero & Hureau, 1996: 374 , fig. 3 [transfer of species to Auchenipterichthys ]. – Taphorn et al., 1997: 83 [ Venezuela]. – Wallace, 2002: 296, figs. 117–118 [rio Negro]. – Ferraris, 2003: 472 [checklist].

Diagnosis. A species of Auchenipterichthys with coracoid bone overlain by thick layer of skin ventrally and not visible ventrally (see Fig. 1c ), an emarginate or obliquely truncate caudal-fin margin, 21 to 24 branched anal-fin rays ( Table 1), nine branched pelvic-fin rays ( Table 1), the anterior teeth on the premaxilla not visible in the closed mouth, and a pattern of body pigmentation consisting of variablysized spots of dark pigmentation scattered over the dorsal and lateral surface of the body and fins. Auchenipterichthys punctatus is most similar in appearance to A. longimanus , which differs from A. punctatus primarily in lacking distinct, dark spots covering the head or body. Auchenipterichthys punctatus is readily distinguished from its other two congeners, A. coracoideus and A. thoracatus , which have coracoids that are covered ventrally only by a thin layer of integument and appear to be exposed to the surface ( Figs. 1 a-b), the anterior teeth on premaxilla are visible in the closed mouth and, typically, eight (rarely nine) branched pelvic-fin rays ( Table 1).

Description. Body depth at dorsal-fin origin 0.25–0.27 of SL and equal to, or slightly greater than body width at cleithrum. Body depth at anal-fin origin approximately 0.25 of SL and equal to HL. Body compressed, with width at anal-fin origin slightly less than one-half of body depth at that point. Ventral surface of coracoids not exposed on ventral surface of body ( 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 caudal fin base and branched with both obliquely posterodorsal and obliquely posteroventral branches.

Head depressed anteriorly; height of head at vertical through middle of orbit greater than distance from middle of eye to dorsal midline of head. Head length 0.23–0.26 of SL. Dorsal profile of head broadly convex anteriorly and then straight or very slightly convex from vertical running through anterior margin of orbit to 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 0.57–0.65 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 long, extending posteriorly slightly past middle of length of cleithral spine. Medial mandibular barbel originating immediately posterior of lower lip; adpressed barbel extending posteriorly to point slightly past 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 of closed mouth. 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 progressively decrease to one tooth row posterolaterally.

Dorsal-fin origin at approximately 0.30–0.34 of SL. Length of dorsal-fin base slightly less than one-half of 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 margin of orbit and posterior margin of opercle. Anterior surface of dorsal-fin spine with single series of relatively feeble, antrorse serrae extending nearly to tip of spine; serrae acute in smaller individuals and blunt in larger individuals. Posterior margin of spine with medial row of relatively feeble, irregularly-directed serrae extending nearly to tip of spine. Serrae on anterior and posterior surfaces of spine approximately of equivalent size. Dorsal fin with spinelet, spine, and six slender branched rays. 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 0.23–0.26 of SL and approximately equal to HL. Anal-fin origin located distinctly posterior of middle of SL and slightly posterior of middle of TL. Anal-fin margin straight, with first ray longest and subsequent rays becoming progressively shorter. Last anal-fin ray without membranous attachment to caudal peduncle. Analfin rays iii,21 to iii,24 ( Table 1).

Distal margin of pelvic fin broadly convex, with third branched ray longest. Pelvic-fin insertion situated at middle of SL. Tip of adpressed pelvic fin extending posterior of analfin origin and approximately to base of first branched anal-fin ray. Pelvic-fin rays i,9 ( 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,8 ( Table 1).

Pigmentation pattern in alcohol. Overall ground coloration of adults tan to brown, universally dark on dorsal portion of head and body other than in smaller individuals that may have darker spots scattered over dorsal one-half of body. Midlateral region along lateral line pale other than in smaller individuals. Pale region in such specimens forming narrow, irregularly-margined, horizontal stripe. Lateral and dorsolateral surface of body with series of unpigmented, rounded spots of size most often approximately equal to one-fifth of width of pupil or smaller. Lateral surface of body ventral of lateral line tan to light brown and overlain by variably sized and distributed spots of dark pigmentation. Dark spots proportionally larger in small specimens. Abdomen and lower portion of head posterior of lateral mandibular barbel pale. Margin of lower lip darkly pigmented.

First, second, and sometimes third interradial membranes of dorsal fin dark distally with remainder of fin in larger individuals with scattered, dark spots similar in size to those on lateral surface of body. Adipose fin generally dark with single darker subterminal spot within field of dark pigmentation, but with pale margin. Caudal fin typically dark on basal portion of rays and membranes, with dark basal region bordered by lighter, near vertical band, and distal tip of fin somewhat darker than coloration of vertical band. Spots of darker pigmentation scattered over all of fin; spots on basal onehalf of fin larger than those on remainder of fin. Ground coloration of anal fin comparable to that of adjoining ventral portion of body, but with broad, darker, distal margin on fin. Anal fin with scattered, small, darker spots over entire surface. Ground coloration of pelvic fin comparable to that of adjoining portions of body; with small, scattered, darker spots throughout. Pectoral fin darkly pigmented on distal portions of first two interradial membranes and generally lighter across remainder of fin. Pectoral spine dark along entire dorsal surface.

Maxillary and lateral mandibular barbels darkly pigmented throughout. Medial mandibular barbel more lightly pigmented.

Color pattern of juvenile specimens similar to that described above, but patterning bolder and spots proportionally larger than those found in adults ( Fig. 8 ).

Sexual dimorphism. No nuptial males were examined in the course of this study and as such it is uncertain whether Auchenipterichthys punctatus demonstrates the sexually-dimorphic features occurring in some congeneric species. Soares-Porto (1994: 285) noted that the males she examined in her description of A. dantei did not demonstrate any sexual differences relative to females other that for their urogenital modifications.

Distribution. Examined specimens originated in the upper portions of the Orinoco and Negro River basins in Venezuela and the central portions of the Amazon River basin in Brazil ( Fig. 10 ; triangles). Soares-Porto (1994, fig. 6) also examined material of the species that originated along the length of the Brazilian portion of the Negro River.

Remarks. Auchenipterus punctatus appears not to have been cited in the literature following its description by Valenciennes (in Cuvier & Valenciennes, 1840) until it was discussed by Royero & Hureau (1996), who first recognized that it represented a species of Auchenipterichthys . Perhaps as a consequence of that situation, this species was subsequently redescribed as A. dantei by Soares- Porto (1994).

Material examined. BRAZIL. Amazonas: rio Riozinho, right bank of rio Jutaí (approximately 2°58’S, 66°58’W), MZUSP 43333 , 2 (99–116) . rio Tefé , lago, MZUSP 52105 , 1 (120) . Rio Negro , lago on island, MZUSP 31076 , 1 (51) . Município Santa Isabel do Rio Negro , MZUSP 84736 , 1 (111) . VENEZUELA. Amazonas: rocks in río Atabapo at shore and inlet of Isla de Sapo, approximately 1.2 hours above San Fernando de Atabapo (latter locality at 4°02’25"N, 67°42’08"W), FMNH 103481 , 1 (76) . Caño Cuchaken, approximately 7 km from its confluence with río Atabapo (3°31’N, 67°24’W), MCNG 23085 , 1 (137) . Vicinity of “Puerto Esperanza” (4°42’37"N, 67°44’58"W), MCNG 35949 , 2 (111–112) . Along river bank at la Comunidad de “Maraya” (3°59’24"N, 66°57’08"W), MCNG 46391 , 1 (68) . Río Siapa approximately 124 km from mouth of Río Casiquiare (1°49’N, 65°48’W), MCNG 25981 , 1 (149) . Caño Candela, near its confluence with río Pasimoni (1°32’06"N, 66°34’34"W), MCNG 42191 , 8 (58–86).

Figures

Fig. 8. Auchenipterichthys punctatus, MCNG 42191, 58 mm SL; Venezuela,Amazonas, Caño Candela, near its confluence with río Pasimoni (1°32’06"N, 66°34’34"W).

Fig. 9. Auchenipterichthys punctatus, MCNG 25981, 149 mm SL; Venezuela,Amazonas, río Siapa approximately 124 km from mouth in río Casiquiare (1°49’N, 65°48’W).

Fig. 10. Map of central and northern South America showing distribution of Auchenipterichthys punctatus (triangles; holotype locality inexact = “probably Brazil”, 1 = holotype locality of Auchenipterichthys dantei), and A. thoracatus (dots; 2 = Guaporé, presumably = rio Guaporé, the type locality of species) (some symbols represent more than one locality or lot of specimens).

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.