Scyliorhinus cabofriensis Soares, Gomes & de Carvalho, 2016

Soares, Karla D. A. & De, Marcelo R., 2019, The catshark genus Scyliorhinus (Chondrichthyes: Carcharhiniformes: Scyliorhinidae): taxonomy, morphology and distribution, Zootaxa 4601 (1), pp. 1-147 : 18-20

Scyliorhinus cabofriensis Soares, Gomes & de Carvalho, 2016

( Figs. 10A , 11 )

Scyliorhinus sp. Nunan & Senna, 2007: 167, figs. 1c, d (catalogue, outer shelf and continental slope of Brazil). Scyliorhinus cabofriensis Soares, Gomes & de Carvalho, 2016: 503 –513, figs. 1–8 (original description, type locality: Rio de Janeiro, Brazil); Rincón et al., 2017: 95 (listed).

Holotype. MNRJ 40730 , female, 395 mm TL ( Cabo Frio , Rio de Janeiro, southeastern Brazil).

Paratypes. MCP 47874, female, 313 mm TL (Rio de Janeiro, southeastern Brazil) ; MCP 47875, female 325 mm TL (Rio de Janeiro, southeastern Brazil) ; MCP 47876, female, 276 mm TL (Rio de Janeiro, southeastern Brazil); MNRJ 40731, female, 285 mm TL (Rio de Janeiro, southeastern Brazil); MNRJ 40732, male, 420 mm TL (Rio de Janeiro, southeastern Brazil); MNRJ 40733, female, 281 mm TL (Rio de Janeiro, southeastern Brazil); MZUSP 37284, male, 393 mm TL (Rio de Janeiro, southeastern Brazil); UERJ 2042, female, 401 mm TL (Rio de Janeiro, southeastern Brazil); UERJ 2231.2, male, 454 mm TL (Rio de Janeiro, southeastern Brazil); UERJ 2231.4, female, 393 mm TL (Rio de Janeiro, southeastern Brazil) .

Additional material examined. 12 specimens (see Appendix).

Diagnosis. Scyliorhinus cabofriensis differs from all congeners by presenting a color pattern composed of well-defined dark spots along the whole body, predominantly smaller than spiracles, and inconspicuous saddles (vs. dark spots absent in S. capensis , S. comoroensis , S. hesperius , S. meadi , S. torazame , and S. torrei ; spots predominantly larger than the spiracle and inside the saddles or bordering them in S. boa , S. cervigoni , S. duhamelii , S. garmani , S. haeckelii , S. stellaris , and S. ugoi ; reticulated pattern in S. retifer ; saddles well defined and dark longitudinal stripe present in S. canicula ). The following combination of characters, although less conspicuous, also helps distinguish this species: light spots smaller than spiracles present from the pectoral saddle and continuing posteriorly (vs. spots from the first dorsal fin in S. haeckelii ); saddles without anteromedial and posteromedial projections (vs. projections present in S. ugoi ); anterior nasal flap does not reach the upper lip (vs. nasal flap reaching the upper lip, sometimes covering it, in S. canicula , S, cervigoni , S. comoroensis , S. duhamelii , S. garmani , and S. stellaris ); pelvic apron extending until at least 2/3 of the inner margin pelvic length (vs. extending for almost all the entire length in S. canicula , S. capensis , S. duhamelii , S. torazame , and S. torrei ); clasper with cover rhipidion covered by dermal denticles (vs. denticles absent in S. boa , S. cervigoni and S. retifer ); envelope absent (vs. present in S. boa , S. haeckelii , S. retifer , and S. torrei ); terminal dermal cover smooth (vs. rough in S. canicula and S. capensis ); groove present in the distal portion of the ventral terminal cartilage of clasper (vs. groove absent or poorly developed in S. haeckelii ); terminal 3 cartilage absent (vs. present in S. boa , S. canicula , S. capensis , S. retifer , S. torazame , and S. ugoi ); dorsal terminal 2 cartilage reduced and subtriangular (vs. elongated in S. boa , S. canicula , S. comoroensis , S. duhamelii , S. retifer , S. stellaris , S. torazame , and S. torrei ); ventral terminal 2 cartilage corresponding to 1/4 of ventral terminal cartilage (vs. 1/ 3 in S. haeckelii ); interdorsal space greater than anal base (vs. shorter or similar to the anal base in S. canicula , S. capensis , S. cervigoni , S. comoroensis , S. duhamelii , S. garmani , S. stellaris , and S. torazame ); counts of monospondylous vertebra 37–39 (vs. 44–46 in S. capensis ; 40–45 in S. cervigoni ; 48 in S. garmani ; 46–48 in S. meadi ; 43–47 in S. stellaris ; 32–37 in S. torazame ; 30–35 in S. torrei ); adult males at 393 mm TL and females at 420 mm TL (vs. sizes greater than 450 mm TL in S. capensis , S. cervigoni , S. meadi , S. stellaris , and S. ugoi ; 269 mm and 294 mm, respectively, in S. torrei ).

Etymology. The specific name ‘cabofriensis’ refers to its type and only known locality, off Cabo Frio in northeastern Rio de Janeiro state.

Remarks. Soares et al. (2016) described the clasper of S. cabofriensis with an accessory dorsal marginal cartilage (RD2), which would support the rhipidion (p. 509–510, figs. 5, 6). In this study, this structure is reidentified as a terminal dorsal 2 cartilage ( Fig. 8A ), following Jungersen (1899) and Compagno (1988a). Conservation status unknown.

Figures

FIGURE 8. Clasper of Scyliorhinus boa; dorsal view, USNM 221563, 348 mm TL (Colombia, 12°17’N, 72°40’W). A, external morphology; B, skeleton. crh, cover rhipidion; en, envelope; end, endstyle; erh, exorhipidion; hp, hipopyle; rd, dorsal marginal cartilage; rh, rhipidion; rv, ventral marginal cartilage; t3, terminal 3 cartilage; td, dorsal terminal cartilage; td2, dorsal terminal 2 cartilage; tdc, terminal dermal cover; tv, ventral terminal cartilage; tv2, ventral terminal 2 cartilage. Scale bar = 10 mm.

FIGURE 10. Clasper skeleton of Scyliorhinus species distributed along the southwestern Atlantic; dorsal view of skeleton. A, Scyliorhinus cabofriensis, UERJ 1702, 468 mm TL; B, S. haeckelii, UERJ 2233.6, 449 mm TL; C, S. ugoi, UERJ 1725, 530 mm TL. end, endstyle; rd, dorsal marginal cartilage; rh, rhipidion; rv, ventral marginal cartilage; td, dorsal terminal cartilage; td2, dorsal terminal 2 cartilage; tv, ventral terminal cartilage; tv2, ventral terminal 2 cartilage. Modified from Soares et al. (2015, 2016). Scale bar = 5 mm.

FIGURE 11. Map showing the geographic distribution of Scyliorhinus cabofriensis (yellow circles), S. haeckelii (green circles) and S. ugoi (blue circles) based on material examined in this study. Stars indicate the type localities of species.