Cetopsis candiru Spix & Agassiz, 1829

Vari, Richard P., Ferraris Jr, Carl J. & de Pinna, Mário C. C., 2005, The Neotropical whale catfishes (Siluriformes: Cetopsidae: Cetopsinae), a revisionary study, Neotropical Ichthyology 3 (2), pp. 127-238 : 159-161

Cetopsis candiru Spix & Agassiz, 1829 Figs. 12 , 16 , 17 , Tables 9 -15

Silurus candira .– Cuvier, 1829: 292 [nomen nudum].

Cetopsis candiru Spix & Agassiz, 1829: 13 , pl. 10, fig. 1 [type locality: Brasiliae aequatorialis fluvis (=rivers of Equatorial Brazil)].– Eigenmann & Eigenmann, 1888: 157 [ Brazil: Tabatinga, Jutahy (=Jutaí), Tonantins, Iça]; 1890: 319 [redescription,Amazon basin]; 1891: 36 [in listing of Cetopsis species ].– Boulenger, 1898a: 422 [ Brazil, rio Jurua].– Pearson, 1924: 16 [ Bolivia, Rurrenbaque]; 1937b: 111 [ Bolivia, río Beni-Mamoré basin].– Magalhães, 1931: 106 [ Brazil, feeding habits, distribution].– Fowler, 1940b: 97 [ Bolivia].– Kottelat, 1984: 149 [syntype depository]; 1988: 84 [authorship of species name; syntype depositories].– Weber, 1998: 9 [syntype depository].

Cetopsis spixii .– Swainson, 1839: 308 [unnecessary replacement for Cetopsis candiru Spix & Agassiz, 1829 ].

Cetopsis candira .–Cuvier & Valenciennes, 1840: 386 [redescription].– Bleeker, 1858: 258 [ Brazil].– Cope, 1878: 678 [Peruvian Amazon].

Hemicetopsis candira .– Bleeker, 1862a: 403 [assignment to Hemicetopsis and designated as type species of genus, brief description]; 1862b: 16 [brief description]; 1863: 111 [brief description].

Hemicetopsis candiru .–Eigenmann & Bean, 1907: 664 [Amazon River between Para (=Belém) and Manaos (=Manaus)].– Eigenmann, 1910: 398 [distribution].– Miranda-Ribeiro, 1912: 381 [ Brazil; redescription; common name]; 1914: 11 [ Brazil, Manáos (=Manaus)]; 1920: 15 [ Brazil, rio Madeira].– Fowler, 1915: 238 [Peruvian Amazon]; 1940a: 232 [ Peru, Ucayali River]; 1941: 472, fig. 29 [ Peru]; 1945: 68, fig. 29 [ Peru]; 1954: 3 [literature compilation].– Eigenmann & Allen, 1942: 148 [ Peru: río Ucayali near Cashiboya, río Puinagua at Bretaña; diet; common name].– Gosline, 1945: 54 [distribution].– Ovchynnyk, 1967: 35 [ Ecuador, río Panayuca]; 1968: 255 [ Ecuador, río Panayuca].– Terrazas-Urquidi, 1970: 21 [ Bolivia, río Beni; based on literature].– Baskin et al., 1980: 183 [feeding on offal and blood].– Ortega & Vari, 1986: 15 [ Peru:Amazon basin; common name].– Stewart et al., 1987: 33 [ Ecuador, río Napo].– Burgess, 1989: 292 [in list of species in Hemicetopsis ].– Lauzanne et al., 1991: 69 [ Bolivia, Trinidad].– Barriga, 1991: 56 [eastern Ecuador]; 1994a: 31 [ Ecuador, Parque Nacional Yasuni].– Ferraris, 1996: 164 [form of adductor mandibulae].– Chang, 1998: 26 [ Peru, río Madre de Dios basin, Tambopata-Candamo Reserved Zone].– Silvano et al., 2001: 34, unnumbered fig.on page 35 [ Brazil, rio Jurua].– Vari & Ferraris, 2003: 258 [in check list; synonymy, distribution, common names].

Diagnosis. Cetopsis candiru can be distinguished from all of its congeners by the combination of its relatively shallow body at the origin of the dorsal fin (0.20 of SL or less versus 0.22 of SL or more, respectively) and the form of the teeth on the vomer and dentary (incisiform versus conical, respectively).

Description. Body relatively elongate, rounded in cross-section anteriorly, becoming increasingly laterally compressed posteriorly. Body depth at dorsal-fin origin approximately 0.17- 0.20 of SL and approximately equal to HL. Lateral line on body complete, unbranched, and midlateral; extending from vertical through pectoral-fin base onto, and straight or slightly upturned on, hypural plate and terminating slightly anterior to posterior margin of hypural plate. Dorsal profile of body slightly convex from nape to dorsal-fin origin and straight from dorsal-fin origin to caudal-fin base. Ventral profile of body variably convex along abdomen, approximately straight, but posteriorly slanted, along base of anal fin. Caudal-peduncle depth approximately equal to caudal-peduncle length.

Head triangular overall in lateral view and broadly rounded anteriorly. Dorsal profile of head convex from tip of snout to vertical through eye, straight from that point to nape. Profile of head from dorsal view broadly rounded anteriorly, with margins of head posterior of orbit running approximately in parallel. Jaw musculature not noticeably enlarged on dorsal surface of postorbital portion of head.

Opercular membrane attaching to isthmus posteriorly as far as vertical through pectoral-fin insertion. Opercular opening relatively small; extending dorsally only to pectoral-fin insertion, and extending ventral of pectoral-fin insertion by distance equal to snout length.

Eye situated on dorsolateral surface of head; located entirely dorsal of horizontal extending through pectoral-fin insertion. Middle of orbit at approximately anterior one-fifth of HL. Eye diameter approximately equal to width of anterior nares. Interorbital width approximately equal to two-fifths of HL. Anterior narial opening circular, surrounded by short, anteriorly-directed, tubular rim of skin. Opening of anterior nares located slightly ventral of both horizontal extending through tip of snout and of horizontal running through maxillary-barbel origin. Distance between anterior nares approximately equal to distance between anterior and posterior nares. Posterior narial opening on dorsal surface of head, situated at horizontal extending through anterior margin of orbit; opening ovoid and with long axis of aperture oriented perpendicular to body axis. Entire posterior narial opening bordered by tube of skin, distal margin of tube higher anteriorly. Distance between posterior nares slightly less than distance between contralateral anterior nares.

Mouth inferior; width approximately one-half of HL. Margin of lower jaw distinctly truncate, its posterior extent reaching to vertical through middle of orbit. Premaxillary teeth incisiform and arranged in single elongate row continuous across midline; tooth row in form of gently curved arch.Vomerine teeth incisiform and arranged in single gently curved, continuous row. Dentary with single row of incisiform teeth much larger than those on both premaxilla and vomer.

Maxillary barbel slender, its length approximately equal to one-third of HL; barbel origin located ventral to anterior margin of orbit. Mental barbels approximately equal in size and length to maxillary barbel. Origin of medial-mental barbel situated along vertical through rictus of jaw. Lateral mental-barbel origin located slightly posterior of vertical through rictus of jaw. Tips of adpressed mental barbels falling far short of opercular opening.

Dorsal fin small overall, with length of dorsal-fin base approximately one-fourth of HL. Longest dorsal-fin ray, excluding distal filament on first ray present in mature males, approximately equal in length to one-third of HL. Dorsal-fin spinelet absent. First dorsal-fin ray not spinous; with at least short, distal filament in females and immature males and with elongate, distal, filament in mature males. Distal margin of dorsal fin slightly convex, with first branched ray longest.

Tip of adpressed dorsal fin falling short of pelvic-fin insertion by distance equal to length of pectoral fin. Posterior most dorsal-fin ray without posterior, membranous attachment to body.

Caudal fin shallowly-forked, symmetrical; lobes broadly rounded. Length of longest caudal-fin ray approximately 1.5- 1.6 times length of middle fin rays.

Base of anal fin approximately 0.29-0.31 of SL. Anal-fin origin located distinctly posterior of middle of SL and slightly posterior of middle of TL. Anal-fin margin gently convex for entire length in all individuals. Posterior most unbranched anal-fin ray longest, with subsequent rays becoming gradually shorter in females and immature males, but with fin margin distinctly convex in mature males. Posterior most anal-fin ray without posterior, membranous attachment to body.

Pelvic fin very short, paddle-shaped, with margin symmetrically rounded and middle fin-rays longest. Pelvic-fin insertion situated slightly anterior to middle of SL. Tip of adpressed pelvic fin reaching posteriorly to middle of SL. Medial most pelvic-fin ray without membranous attachment to body.

Pectoral-fin length approximately one-half of HL. Pectoral-fin margin rounded with second branched fin ray longest. First pectoral-fin ray not spinous and without distal filament in females and immature males, but with moderately-developed, distal filament in mature males.

Coloration in alcohol. Body and head with indistinct duskiness dorsally and pale ventrally.

Dorsal and pectoral fins with subterminal, dark, band curving across fin approximately three-fourths of distance from base, with remainder of both fins dusky. Anal, caudal, and pelvic fins unpigmented.

Barbels unpigmented.

Sexual dimorphism. The first ray of the dorsal fin of mature males of Cetopsis candiru is prolonged to varying degrees beyond the condition present in both females and immature males. Mature males also have a moderately-developed, distal filament on the first pectoral-fin ray, whereas such extensions of that fin ray are absent in both females and immature males. The convexity of the anal-fin margin in mature males is distinctly more pronounced than is the form of the fin margin that characterizes both females and immature males of the species. The smallest obviously sexually mature male of C. candiru examined in this study (MZUSP 24602) is 145 mm SL. A slightly smaller 137 mm SL specimen of C. candiru (MZUSP 55634) demonstrated the beginnings of the male sexuallydimorphic features characteristic of the species.

Distribution. Examined specimens of Cetopsis candiru originated across a broad reach of the Amazon basin in Bolivia, Brazil, and Peru ( Fig. 12 ) and the species has been reported from eastern Ecuador by Ovchynnk (1967: 35), Stewart et al. (1987: 33), and Barriga (1991: 56; 1994a: 31).

Common Name. Bolivia: “Candiru,” “Canero” (Terrazas- Urquidi, 1970: 21); Peru: “Canero” ( Ortega & Vari, 1986: 15).

Remarks. Kottelat (1984: 149; 1988: 84) and Weber (1998: 9) reported that four syntypes for Cetopsis candiru are extant. We have examined one of the syntypes (MHNG 210.5) that in combination with the original description, make it clear that the material identified herein as Cetopsis candiru is indeed that species. We herein designate that syntype as the lectotype of Cetopsis candiru .

Material examined. 220 specimens (18-263 mm SL). Bolivia. Beni: río Beni at Rurrenbaque, 1500 ft (= 457 m) elevation (14 o 28’S, 67 o 34’W), CAS 77024, 1 (232). Río Mamoré, Boca río Ibare (14 o 37’S, 64 o 57’W), MNHN 1988-1997 , 5 (105-141). Brazil. “Equatorial Rivers of Brazil,” MHNG 210.5 , 1 (135; lectotype of Cetopsis candiru ; designated herein). Rio Amazonas , between Pará and Manaus, USNM 52546 , 1 (158, mature male). Rio Araguaia , LIRP 581 , 2 (116-132). Acre: Reserva Extrativista doAlto rio Juruá , MZUSP 53015 , 1 (150). Amazonas: rio Solimões approximately 0.5 km from mouth of Paraná de Januacá, on south bank (3 o 25’S, 61 o 21’W), MCZ 56018, 1 (131). Lago Jacaretinga, near Manaus , MCZ 78099, 2 (18-25). Rio Madeira , Borba (4 o 24’S, 59 o 35’W), MNRJ 4819 , 2 (102-197); MZUSP 28350 , 1 (74). Município de Borba , Borba, MZUSP 28349 , 5 . Rio Juruá , Eirunepé (6 o 40’S, 69 o 52’W), MNRJ 5878 , 20 (80-180). Rio Solimões , 6.5 km below Solimões (2°55’25"S, 67°51’23), MZUSP 56822 , 1 (92). Rio Solimões , Ilha dos Corós , above Codajás (3 o 50’S, 62 o 05’W), MZUSP 23249 , 12 (93-205). Rio Jauaperi , from mouth to 100 km upstream, MZUSP 23287 , 1 (140). Rio Solimões , near Tefé (approximately 3 o 22’S, 64 o 42’W), MZUSP 23319 , 3 (87-185, 178 mm specimen mature male). Igarapé em Jacaré, Fonte Boa (2 o 32’S, 66 o 01’W), MZUSP 23355 , 4 (95-125). Mouth of rio Içá , Santo Antonio do Içá (3 o 05’S, 67 o 57’W), MZUSP 23521 , 11 (5, 80-173, largest specimen mature male). Rio Amazonas , Ilha Beiju-Açu (2 o 25’S, 57 o 31’W), MZUSP 23753 , 2 (92-205). Mouth of rio Pauini (7 o 12’S, 69 o 36’W), MZUSP 24595 , 1 (190). Pauini (7 o 40’S, 66 o 58’W), MZUSP 24602 , 1 (145, mature male). Canutama, MZUSP 24615 , 1 (187). Rio Purus , Mapixi (5 o 40’S, 63 o 53’W), MZUSP 24683 , 6 (108- 179, 138 mm specimen mature male); ROM 37966, 5 (121-146). Rio Purus , Tapuru (4 o 18’S, 61 o 47’W), MZUSP 24688 , 4 (116-185; 1 specimen, 185 mm, cleared and stained). Rio Purus , Caitaú, MZUSP 30693 , 1 (93). Rio Purus , at mouth, MZUSP 5969 , 1 (134). Rio Madeira , Humaitá (7 o 31’S, 63 o 02’W), MZUSP 35421 , 8 (197-229); MZUSP 28732 , 8 (147-226). Carauari (4 o 52’S, 66 o 54’W), MZUSP 30696 , 1 (96). Rio Negro , Anavilhanas, along bank of lagoon, MZUSP 31331 , 1 (86). Rio Solimões , Marchantaria, above Manaus (approximately 3 o 08’S, 60 o 00’W), MZUSP 38827 , 2 (168-190, smaller specimen mature male). Rio Amazonas , Ilha do Beijú-Açu (2 o 25’S, 57 o 31’W), MZUSP 52898 , 1 (217). Rio Amazonas , Nova Olinda (3 o 45’S, 59 o 03’W), MZUSP 52899 , 1 (215). Rio Solimões , mouth of lago Preto (approximately 4 o 00’S, 63 o 05’W), MZUSP 5874 , 1 (214). Rio Solimões , between lago Jacaré and rio Purus , MZUSP 5935 , 7 (58-225, 182 mm specimen mature male). Rio Solimões , above Ilha Iauara (approximately 3 o 38’S, 61 o 22’W), MZUSP 6272 , 3 (54- approximately 120; largest specimen cleared and stained). Mouth of lago Panaquequara, MZUSP 6913 , 1 (121). Rio Solimões , paraná do Moreru (3 o 50’S, 69 o 47’W), MZUSP 9599 , 5 (63-83). Rio Negro , 9.3 km below lago da Cotia (1°45’15"S 62°25’08"W), MZUSP 55643 , 15 (95-158, 137 mm specimen demonstrates indications of male sexually-dimorphic features). Goiás: Município de Minaçu / Cavalcante, rio Tocantins , at site of future dam of Usina Hidroeléctrica Serra da Mesa (13 o 50’S, 48 o 19’W), MNRJ 13250 , 2 (94-103). Serra da Mesa , MZUSP 54086 , 2 (104-108). Pará : Boa Fé, Furo de Tajapuru (4 o 36’S, 56 o 12’W), MZUSP 24228 , 1 (154). Ilha Redonda , near Gurupá (1 o 25’S, 51 o 39’W), MZUSP 24229 , 2 (110-143). Rio Amazonas , Taperinha (2 o 32’S, 54 o 17’W), MZUSP 24232 , 1 (116). Rio Trombetas , at mouth of lago Paui, Oriximiná (1 o 45’S, 55 o 22’W), MZUSP 5684 , 4 (42-133). Rio Amazonas , Itamarati, exit from Furo de Tajapuru (1 o 08’S, 51 o 11’W), MZUSP 9140 , 2 (117-130). Rio Amazonas , Óbidos (1 o 55’S, 55 o 31’W), MZUSP 9543 , 1 (120). Rondônia: rio Madeira , Foz do Jamarí (8 o 45’S, 63 o 27’W), MZUSP 28371 , 1 (173). Rio Madeira , Porto Velho (8°45’S, 63°54’W), MZUSP 36764 , 2 (174-179). Tocantins: rio Tocantins at Porto Nacional (10 o 42’N, 48 o 25’W), CAS 6610 , 1 (210); CAS 77023, 1 (203). Indefinite locality: MZUSP 48102 , 15 (94-186; 3 specimens, 82-130 mm, cleared and stained). Peru. Río Cucaya , at its mouth, CAS 16024, 1 (116; co-ordinates of location unknown). Amazonas: río Santiago , 1.5 km upstream of La Poza (latter locality at: 4 o 01’S, 77 o 45’W), LACM 39864-2 , 4 (244-263). Loreto: rio Amazonas , between Iquitos and mouth of rio Marañon , along E bank, AMNH 78109 SW, 2 (~123-175; specimens cleared and stained). Rio Amazonas , at Ramón Castilla (4 o 14’S, 69 o 57’W), CAS 65902, 12 (67-118). Río Yaguas at Puerto Armondito, from inside a Brachyplatystoma, CAS 65904, 1 (142). Pebas (approximately 3 o 20’S, 71 o 49’W), ANSP 21502 , 3 (183-220; locality originally reported as being in Ecuador). RíoAmazonas, near Pebas (approximately 3 o 20’S, 71 o 49’W), CAS SU 17205 , 1 (192). Río Ambiyacu , near Pebas (approximately 3 o 20’S, 71 o 49’W), CAS SU 36190 , 1 (238). Contamana, río Ucayali basin (7°30’S, 75°01’W), ANSP 88079 , 2 (140-165). Río Pastaza basin, caño tributary to laguna Rimachi, near río Rimachi , at Rimachi (4°26.91’S, 76°39.48’W), FMNH 112635 , 1 (194); FMNH 112634 , 1 (136). Madre de Dios : río Madre de Dios , Albergue Cuzco- Amazonico, CAS 59458, 1 (144). Río Tambopata , Tambopata, Departamento Tres Chimbadas (12 o 47’29"S, 69 o 19’13"W), MUSM 9851 , 3 (206-210). Ucayali: río Ucayali near lago Cashiboya (7 o 33’S, 74 o 53’W), CAS 16023, 8 (97-139). Río Ucayali , Pucallpa (8 o 23’S, 74 o 32’W), MZUSP 26419 , 1 (123); MUSM 13257 , 1 (104). Río Ucayali , Masisea (8 o 36’S, 74 o 19’W), MZUSP 35934 , 1 (128). Río Ucayali , Pucallpa (8 o 23’S, 74 o 32’W), MZUSP 35935 , 1 (117). Río Ucayali , Nueva Ytalia, near Cashiboya (7 o 33’S, 74 o 53’W), USNM 167854 , 6 (130-152; 2 specimens cleared and stained) .

Figures

Fig. 12. Map of central and northern SouthAmerica showing geographic distribution of Cetopsis amphiloxa (1 = holotype locality of Hemicetopsis amphiloxus), Cetopsis arcana (2 = holotype locality), Cetopsis baudoensis (3 = holotype locality of Pseudocetopsis baudoênsis), Cetopsis caiapo (4 = holotype locality), and Cetopsis candiru (type locality inexact = rivers of Equatorial Brazil) (some symbols represent more that one locality and/or lot of specimens).

Fig. 16. Cetopsis candiru, MCZ 56018, female, 131 mm SL; Brazil,Amazonas, rio Solimões approximately 0.5 km from mouth of paraná de Januaca, on south bank of river (3o25’S, 61o21’W).

Fig. 17. Cetopsis candiru, mature male, FMNH 112635, 194 mm SL; Peru, Loreto, río Pastaza basin, caño tributary to laguna Rimachi, near río Rimachi, at Rimachi(4°26.91’S, 76°39.48’W).