Scyliorhinus ugoi Soares, Gomes & Gadig, 2015

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 : 126

Scyliorhinus ugoi Soares, Gomes & Gadig, 2015

( Figs. 10C , 11 )

Common names: cação-gato negrinho ( Brazil), dark freckled catshark ( United States).

Scyliohinus sp.: Gomes et al., 2010: 85–86, fig. 110 (catalogue, Rio de Janeiro, Brazil).

Scyliorhinus hesperius: Gadig & Gomes, 2003: 22 (catalogue, Brazil).

Scyliorhinus ugoi Soares, Gomes & Gadig, 2015: 348 –361, figs. 1-9 (original description, type locality: Bahia, Brazil); Weigmann, 2016: 44 (listed); Rincón et al., 2017: 94 –95, fig. 4j (catalogue, Brazil).

Holotype. MNRJ 42619, female, 496 mm TL (southern Bahia, Brazil).

Paratypes. MZUSP 110448, male, 465 mm TL (Alagoas, northeastern Brazil, 9°S 34°50’W) ; MZUSP 110449, male, 445 mm TL (Rio Grande do Norte, northeastern Brazil, 6°14’S 34°51’W) ; UERJ 1725 , male, 530 mm TL (somewhere between southern Bahia and northern Rio de Janeiro; neurocranium, jaws and claspers) ; UERJ 2179 , male, 415 mm TL (southern Bahia, Brazil)

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Additional material examined. 21 specimens (see Appendix).

Diagnosis. Scyliorhinus ugoi differs from all congeners by presenting a color pattern composed of saddles with antero- and posteromedial projections (vs. projections absent in other species); dark spots spiracle-sized to greater than the spiracles (vs. dark spots absent in S. capensis , S. comoroensis , S. hesperius , S. meadi , S. torazame , and S. torrei ; reticulate pattern in S. retifer ; spots predominantly smaller in S. boa and S. cabofriensis ), spots restricted to saddles and not bordering them (vs. spots over entire body in S. cabofriensis ; bordering saddles in S. boa ); adult males at least 445 mm TL and adult females at least 500 mm TL (vs. adult sizes smaller than 420 mm TL in S. boa , S. cabofriensis , S. haeckelii , S. torazame , and S. torrei ; sizes greater than 500 mm TL in S. capensis , S. cervigoni , S. meadi , and S. stellaris ). The following combination of characters, although less conspicuous, also helps distinguish this species: lunate spots and double points absent (vs. present in S. cabofriensis and S. haeckelii ); anterior nasal flaps not reaching the upper lip (vs. flaps reaching the lip, sometimes covering it in S. canicula , S. cervigoni , S. comoroensis , S. duhamelii , S. garmani , and S. stellaris ); mesonarial ridge not exceeding the posterior border of anterior nasal flaps (vs. exceeding it in S. stellaris ); pelvic apron extending to 2/3 the length of pelvic inner margins (vs. extending through almost entire length of pelvic margins in S. canicula , S. capensis , S. duhamelii , S. torazame , and S. torrei ); clasper with cover rhipidion covered by dermal denticles (vs. absent in S. boa , S. cervigoni , S. hesperius , and S. retifer ); terminal dermal cover smooth (vs. rough in S. canicula and S. capensis ); terminal 3 cartilage absent (vs. present in S. boa , S. canicula , S. capensis , S. retifer , and S. torazame ); 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 ); counts of monospondylous vertebrae 38–39 (vs. 46 in S. capensis ; 40–45 in S. cervigoni ; 48 in S. garmani ; 46–48 in S. meadi ; 43–47 in S. stellaris ; 30–35 in S. torrei ).

Etymology. The specific name ‘ugoi’ was dedicated to Ugo de Luna Gomes, son of the elasmobranch researcher Ulisses Leite Gomes.

Remarks. Soares et al. (2015) described the clasper of S. ugoi with an accessory dorsal marginal cartilage (RD2), which would support the rhipidion (p. 352, 353, 356, figs. 5, 6). In this study, this structure is reidentified as a dorsal terminal 2 cartilage ( Fig. 8C ), following Jungersen (1899) and Compagno (1988a). Some specimens captured in Pernambuco and Rio Grande do Norte, Brazil (UERJ 2178, UFPB 5294 and other uncatalogued specimens), present a color pattern distinct with grayish background color, dark spots smaller than the spiracles throughout the body and light spots less frequent inside the saddles. These specimens are tentatively classified as S. ugoi and we highlight the need to obtain more specimens for a more detailed study of these populations.

Specimens USNM 221611 and USNM 221652, USNM 221561 and, UF 77857, previously identified as Scyliorhinus boa , S. hesperius and S. retifer , respectively, present a color pattern similar to S. ugoi with antero- and posteromedial projections in the saddles, light and dark spots similar in size or smaller than the spiracle, scattered all over the body. These specimens are tentatively identified here as S. ugoi , which in turn extends the geographic range of this species from northern Rio de Janeiro, Brazil to Barbados, Caribbean Sea ( Fig. 9 ). No data on the conservation status of this species was found.

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 9. Map showing the geographic distribution of Scyliorhinus boa based on material examined in this study. Black star indicates the type locality.

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.