Broadmouth Catshark

Apristurus macrostomus Chu, Meng

Apristurus macrostomus Chu, Meng & Li, 1985 Type locality: off Zhujiang, South China Sea. The 13 Taiwanese samples of A. macrostomus formed a single cluster that includes other previously collected samples from Taiwan (Supplementary Material 1). Sample GN1013 is labeled as A. macrorhynchus in Naylor et al. (2012a, 2012b). Based on results of this study, the sample may have to be transferred to A. macrostomus . This clade is closest to, but very distinct from, an A. exsanguis clade from New Zealand.

A DNA sequence-based identification checklist for Taiwanese chondrichthyans

description

Apristurus platyrhynchus: Shen & Wu, 2011: 63 (description, Taiwan).

A review of the genus Apristurus (Chondrichthyes: Carcharhiniformes: Scyliorhinidae) from Taiwanese waters

description

Description. Proportional measurements and meristic counts are given in Table 4. Body cylindrical, slender and elongate (Figure 22). Head dorso-ventrally flattened, posterior part of body compressed laterally. Snout rather long; tip ball-shaped. Pre-outer nostril length 1.3 – 1.9 times internarial width. Pre-oral length slightly less than pre-orbital length, 2.5 – 3.4 times internarial width, subequal to mouth width and greater than interorbital width. Pre-orbital length 1.7 – 2.1 times interorbital length, 2.9 – 4.2 times orbit length. Internarial width subequal to orbit length and nostril width. Nostril relatively large, expanding obliquely inward from snout edge; length about half of pre-inner nostril length. Nostril-mouth space about half of internarial width. Mouth broadly arched, with well developed labial furrows; upper labial furrows 1.1 – 1.6 times longer than lower one. Upper labial furrow reaching beyond midpoint between mouth corner and posterior margin of nostril. Orbit narrow and slender, with a weak subocular fold. Spiracle small placed slightly below level of horizontal axis of orbit. Five small gill slits present; fourth gill slit above pectoral-fin origin; fifth g

A review of the genus Apristurus (Chondrichthyes: Carcharhiniformes: Scyliorhinidae) from Taiwanese waters

description

macrorhynchus), first dorsal fin originating behind the pelvic fin base (above or before pelvic fin insertion in A. macrorhynchus), and by having fewer vertebrae (more in A. macrorhynchus; Figure 28). A. macrostomus Taiwan Holotype Other regions 26 males, 20 females male 9 males, 12 females P 1 anterior margin 9.1 – 12.4 13.9 9.8 – 14.7 ...... continued on the next page A. macrostomus Taiwan Holotype Other regions 26 males, 20 females male 9 males, 12 females P 2 length 8.7 – 12.1 11.3 10.2 – 12.7 Anal base length (ceratotrichia) 14.7 – 18.9 15.9 13.4 – 19.2 Anal height (muscle) 2.6 – 5.1 4.5 3.1 – 5.1 Caudal length 29.4 – 33.9 31.4 29.9 – 35.2 Clasper outer length 1.5 – 6.0 6.0 1.4 – 6.2 Counts Tooth rows: upper 63 – 86 76 62 – 84 lower 55 – 80 73 65 – 81 Vertebrae: monospondylous 34 – 37 ― 31 – 36 precaudal diplospondylous 33 – 40 ― 31 – 37 Spiral valves 18 – 21 ― 18 – 21 Apristurus macrostomus and A. platyrhynchus are quite similar each other morphologically, but they are apparently different species. A. macrostomus is a small-sized species attaining up to 57 cm TL, and begins to mature at around 40 cm TL. On the other hand, A. platyrhynchus is a large-sized species attaining 80

A review of the genus Apristurus (Chondrichthyes: Carcharhiniformes: Scyliorhinidae) from Taiwanese waters