Western Humpback Dogfish

materials_examined

Holotype: MZUSP 118707; adult female; 733 mm TL (cited as 700 mm TL in Viana et al., 2016) (Fig. 3); off the coast of Rio Grande do Sul, Brazil; depth not listed; collector not listed; collection date not listed. Notes: Two skin samples removed from the dorsal region, close to first dorsal fin (Fig. 3 upper and middle pictures).

Type specimens of Elasmobranchii in the Museu de Zoologia da Universidade de São Paulo (MZUSP)

description

Description. External morphology. Measurements and meristic data are summarized in Tables 7 – 8. Body markedly robust and humped dorsally, more slender from pelvic fins to caudal fin; body extremely deep from head to tail (head width 1.0, 0.8 – 1.0 times trunk height and 0.9, 0.7 – 1.2 times abdomen height), very wide at head (head width 1.2, 1.2 – 1.4 times greater than trunk width, and 1.7, 1.3 – 1.9 times greater than abdomen width). Head flattened dorsally from snout to spiracle and elongate, its length 24.7 % (22.2 % – 23.0 % TL), corresponding to 1.3 (1.0 – 1.1) times dorsal caudal margin length. Snout strongly pointed at tip and elongate (preorbital length 7.9 %, 6.8 % – 7.7 % TL); anterior margin of nostrils broad and bilobate, placed ventrolaterally in snout; prenarial length 1.0 (1.0 – 1.1) times distance from nostrils to upper labial furrow and 1.4 (1.0 – 1.4) times larger than eye length; width between nostrils narrow (length 5.0 %, 3.9 % – 4.1 % TL), corresponding to 1.4 (0.8 – 1.2) times eye length. Eyes oval with anterior margin convex and posteriorly notched, very large, its length 3.5 %, 3.1 % – 4.9 % TL and corresponding to 2.6 (2.2 – 3.3) times its height. Prespi

Taxonomy and morphology of species of the genus Squalus Linnaeus, 1758 from the Southwestern Atlantic Ocean (Chondrichthyes: Squaliformes: Squalidae)

description

Squalus quasimodo is distinct from S. lobularis by having a shorter second dorsal-fin spine (length 4.4 %, 3.9 % – 4.3 % TL vs. 5.3 %, 3.4 % – 5.3 % TL in S. lobularis), and second dorsal-fin spine length 1.0 (1.0 – 1.2) times greater than first dorsal-fin spine length (vs. 1.4, 1.0 – 1.6 times in S. lobularis). Squalus quasimodo also has slightly shorter prenarial and preoral lengths than S. bahiensis (prenarial length 4.8 %, 4.5 % – 4.9 % TL vs. 5.0 %, 4.9 % – 5.1 % TL in S. bahiensis and preoral length 10.2 %, 9.5 % – 10.0 % TL vs. 9.9 %, 10.2 % – 10.5 % TL in S. bahiensis). Squalus quasimodo has a larger number of monospondylous vertebrae than S. crassispinus, S. megalops, S. raoulensis, S. grahami, S. nasutus, and S. hemipinnis based on data provided by Last et al. (2007) (Table 12): 45, 46 in S. quasimodo vs. 41, 39 – 42 in S. crassispinus, 37 – 40 in S. megalops, 41, 41 – 43 in S. raoulensis, 40, 38 – 42 in S. grahami, 39, 36 – 39 in S. nasutus, and 36, 35 – 38 in S. hemipinnis. It is also distinguished from S. mitsukurii, the Mediterranean S. blainvillei, and S. chloroculus, S. montalbani, and S. notocaudatus of Last et al. (2007) by total vertebrae (116, 120 – 121 in S. qu

Taxonomy and morphology of species of the genus Squalus Linnaeus, 1758 from the Southwestern Atlantic Ocean (Chondrichthyes: Squaliformes: Squalidae)

description

Suggested common names: Humpback Western dogfish; cação-bagre-corcunda (Portuguese)

Taxonomy and morphology of species of the genus Squalus Linnaeus, 1758 from the Southwestern Atlantic Ocean (Chondrichthyes: Squaliformes: Squalidae)