Pseudoplatystoma corruscans (Spix & Agassiz, 1829)

Uriel Angel Buitrago-Suárez & Brooks M. Burr, 2007, Taxonomy of the catfish genus Pseudoplatystoma Bleeker (Siluriformes: Pimelodidae) with recognition of eight species., Zootaxa 1512, pp. 1-38 : 14-18

Pseudoplatystoma corruscans (Spix & Agassiz, 1829)

(Figure 16, Table 3)

Platystoma corruscans Spix & Agassiz, 1829 :26 [pl. 13]. Type locality: in Flumine S. Francisci ( Brazil). Holotype: whereabouts unknown. As Sorubim caparary on plate.

Sorubim caparary Spix & Agassiz, 1829 : pl. 13. Type locality: in Flumine S. Francisci (Brazil). Holotype: whereabouts unknown. Name available from plate.

Platystoma coruscans Valenciennes in Cuvier and Valenciennes, 1840:17 (p. 13 in the Strasbourg deluxe edition]. Type locality: unknown.

Silurus macrocephalus Larranaga, 1923 : 386. Type locality: Uruguay. Lundberg & Littmann (2003) stated this name corresponds to Silurus mangrullo on p. 377, as name only (see Devincenzi 1926: 310, 322).

Neotype: MCP 14071 , (1), 700 mm SL. Sao Francisco River, Minas Gerais, Tres Marias e Pirapora , 18º13'S, 45º15'W, state of Minas Gerais, Brazil, Y. Sato, November 1987.

Geographic distribution: Paraná River and São Francisco River (Fig. 17) in the countries of Argentina, Brazil, Paraguay, and Uruguay.

Type locality: No precise location in the original description. Spix and Agassiz (1829) reported the locality as Flumine S. Francisci Brasiliae mediae as the habitat of the species.

Material examined: ANSP 46327 , (1 ds), Buenos Aires , Argentina, H. W Fowler, 1916. BMNH 1878- 10298 , (1), La Plata River , La Plata, Buenos Aires , Argentina, W. White, 1878. BMNH 1934-820113120 , (6; 2 ds), Paraguay River, near Asuncion , Parana River , Paraguay, G. Schouten, 1934. CAS 76846 , (2), Paraguay River, tributary Parana River, Asuncion , Paraguay, J. D. Anisits, March 1900. CAS 152882 , (1), Pirapora, Sao Fancisco River , state of Minas Gerais, Brazil, G. S. Myers et al., 12 October 1942. CAS 52883 , (1), Pirapora, Sao Fancisco River , state of Minas Gerais, Brazil, G. S. Myers et al., 12 October 1942. FMNH 58037 , (2), Joazeiro, Sao Francisco River , state of Bahia, Brazil, J. D. Haseman, 11/28/1907. MCP 14114 , (1), Sao Francisco River , Minas Gerais, between Tres Marias and Pirapora , 18°13'S, 45°15'W. MCP 14070 , (1), Sao Francisco River, Minas Gerais, Tres Marias e Pirapora , state of Minas Gerais, Brazil, Y. Sato, November 1987. MCZ 7316 , (1), below the falls, probably near Piraporal, Sao Francisco River , state of Minas Gerais, Brazil, F. C Hartt, 1867. NRM 31891 , (1), Paraguay River at club Puente Remanso , 25°11"3"N, 57°32'W, purchased from local fishermen, Paraguay, B. Delling et al., 21 October 1994. SIUC 33082 , (2; 1 ds), Porto Rico island, Parana River 22°45'S, 53°15'W, state of Paraná, Brazil. C. S. Pavanelli, 20 July 1998. USNM 181766 , (1), Asuncion bay, Paraguay River, near Asuncion , Paraguay, C. J. Brown, 27 December 1956. USNM 181765 , (2), Asuncion bay, Paraguay River, near Asuncion , Paraguay, C. J. Brown, 10 January 1957. USNM 181774 , (2), Asuncion bay, Paraguay River, near Asuncion , Paraguay, C. J. Brown, 20 December 1956. USNM 002114 , (1), Paraguay (data on precise location is missing).

Diagnosis: A species of Pseudoplatystoma distinguished by a combination of the following features: body covered by large spots distributed regularly in six to eight rows from posterior margin of opercle to tail; pale vertical bars on sides of body varying from 4-13; adipose fin containing 5 to 10 or no spots; caudal fin with few spots, some individuals with no spots on the ventral lobe; 44-47 vertebrae (see Table 9); surrounding region of both ventral and dorsal procurrent caudal rays with no spots.

Description: Maximum recorded length 1140 mm TL. Pseudoplatystoma corruscans has the same profile as other members of the P. fasciatum clade. Body somewhat stout. Viewed dorsally, widest measurement at level of dorsal fin origin, decreasing gradually to tail. Lateral sides of head almost parallel. Pigmentation dark brownish on top and sides of body and head, with spots distributed in rows. A row of spots may be present below lateral line. Pale vertical bars on lateral region of body from opercle flap to caudal peduncle, varying from 4-13 (modally 4-7). No straight vertical or loop-like dark bars. Dorsal region of head with no loops, a few individuals with spots. Dorsal fin rays bearing small spots. Pectoral fin dark and with no spots. Pelvic fin pale, and between 3-6 spots. Anal fin variable, pale, dark, or spotted. A comparison with other species is in Table 9. Color and pattern of adults are shown in Fig. 18.

Remarks: Swarça et al. (2005) reported the karyotype (2n = 56) for two populations ( Paraná and Paraguay rivers) of P. corruscans in Brazil and noted differences in karyotype structures that might suggest cryptic species masquerading under one name. We have been unable to find trenchant phenotypic differences in specimens of P. corruscans examined from several locations in separate drainage systems and have no additional morphological data that might support the notion of cryptic species.