Taxonomic review of catsharks of the Scyliorhinus haeckelii group, with the description of a new species (Chondrichthyes: Carcharhiniformes: Scyliorhinidae)

Abstract

Sharks of the genus Scyliorhinus from the southwestern Atlantic are reviewed; identification problems and taxonomic misinformation given in the literature are rectified. After extensive examination of the external and internal morphology of specimens collected mostly off southeastern and southern Brazil, Scyliorhinus besnardi Springer & Sadowsky, 1970 is placed in the synonymy of S. haeckelii (Miranda Ribeiro, 1907), which is thoroughly redescribed. Additionally, a new species, Scyliorhinus cabofriensis, sp. nov., is described from the state of Rio de Janeiro, distinguished from all southwestern Atlantic congeners by its color pattern, clasper and neurocranial morphology, and proportional measurements. A key to Scyliorhinus species occurring in the southwestern Atlantic is also provided.

Deep-Water Sharks, Rays, and Chimaeras of Brazil

“…The geographic distribution of the species ranges from Rio Grande do Sul up north to at least Rio de Janeiro. A recent taxonomic review of the S. haeckelii-besnardi complex [89] confirms that S. besnardi Springer and Sadowsky 1970 is a junior synonym of S. haeckelii with a grade on the color pattern [90,91] (Figure 4). A new species (S. ugoi) was described on the northeast slope based on specimens with a lighter color pattern on the dorsal surface when still alive [92].…”

Sexually dimorphic body proportions in the catshark genus Scyliorhinus (Chondrichthyes: Carcharhiniformes: Scyliorhinidae)

“…Many studies have focused on biological aspects and morphological characteristics of the lesser spotted dogfish Scyliorhinus canicula (Linnaeus, 1758), but little is known about other species of the genus. Sexual dimorphism in Scyliorhinus has been previously reported in their colour pattern (Soares et al, 2016), dermal denticles , teeth, jaws and head measurements (Ellis & Shackley, 1995;Litivinov, 2003;Erdo gan et al, 2004;Filiz & Taşkavak, 2006), mouth shape (Soares et al, 2015(Soares et al, , 2016, and ampullae of Lorenzini . Many studies have been published about the differences in body size between the sexes of catshark species, but only few present more detailed information on proportional dimensions (Ellis & Shackley, 1995;Erdo gan et al, 2004;Filiz & Taskavak, 2006 (Garman, 1881) and Scyliorhinus torazame (Tanaka, 1908) from Japanese waters.…”

“…The genus Scyliorhinus Blainville 1816 (family Scyliorhinidae) comprises 16 species with varied colour patterns (Ebert et al, ). These species are mostly distributed around the Atlantic Ocean but some species are also found in the waters of Japan and the north‐west coast of Madagascar (Compagno et al, ; Ebert et al, ; Soares et al, , ; Springer, ). Many studies have focused on biological aspects and morphological characteristics of the lesser spotted dogfish Scyliorhinus canicula (Linnaeus, ), but little is known about other species of the genus.…”

“…Fifty‐nine measurements per individual were taken (Figure ), following Soares et al . () and converted to percentages of total length (% L T ). Size correction was performed by using residuals from multivariate regression of shape and size to remove the allometric component of shape variation, considering the Gould‐Mosimann allometry framework (Gould, ; Klingenberg, ; Mosimann, ).…”

“…Males and females of S. canicula (n = 209), S. capensis (n = 75), S. haeckelii (n = 125), S. retifer (n = 221) and S. torazame (n = 117) were measured, totalling 747 specimens. Fifty-nine measurements per individual were taken ( Figure 1), following Soares et al (2016) and converted to percentages of total length (%L T ). Size correction was performed by using residuals from multivariate regression of shape and size to remove the allometric component of shape variation, considering the Gould-Mosimann allometry framework (Gould, 1966;Klingenberg, 2016;Mosimann, 1970).…”