Cephaloscyllium formosanum Teng 1962
Creators: name: Nakaya, Kazuhiro
name: Inoue, Shinsuke
name: Ho, Hsuan-Ching
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Elasmobranchii
Carcharhiniformes
Scyliorhinidae
Cephaloscyllium
Cephaloscyllium formosanum

description: Cephaloscyllium formosanum Teng, 1962
English name: Formosa swellshark Taiwanese name: Tai-wan-tou-sa Japanese name: Hoshi nanukazame (Figure 9, Table 4)
Cephaloscyllium formosanum Teng, 1962: pp. 48–51, fig. 11.
Material examined. Holotype: TFRI 4339, female, 655 mm TL (off Tungkang [Dong-gang], western South Taiwan, 22º25’N, 120º25’E). The holotype was examined by Inoue in 2002 at TFRI, but it was missing (maybe lost) when KN and HH visited TFRI in October, 2012.
Diagnosis. Four broad dark saddle blotches before first dorsal fin; first saddle just behind eye, second saddle over gill openings, third saddle above inner margin of pectoral fin and fourth above pelvic fin origin. A narrow dark band between third and fourth saddle blotches. Numerous small white spots on all body. Margins of egg case indented. Medium-sized species getting mature at size less than 65 cm TL.
Description. Proportional measurements and meristic counts are given in Table 4.
Body slender (Figure 9). Head large and well depressed. Trunk height at pectoral insertion higher than height of head. Tail slightly compressed. Caudal peduncle without pit and keel. Caudal axis a little elevated. Snout comparatively long, tip rounded, length greater than 1st dorsal and anal fin bases. Nostrils near mouth. Anterior nasal flap well developed, sub-triangular with a small notch on its posterior margin; flap not reaching mouth. Posterior nasal flaps developed. Internarial space comparatively wide, almost equal to nostril width. Mouth very wide, its length longer than eye length; anterior part of lower jaw rounded. Labial furrows completely absent from both jaws. Eye small, length less than preoral length. Spiracle small, behind and slightly below eye. Gill openings short; first opening longest, smaller toward fifth opening; fourth and fifth openings on base of pectoral fin.
Pectoral fin moderate in size; its apex and free rear tip moderately rounded; its posterior margin somewhat linear. First dorsal fin origin above center of pelvic fin base; base length shorter than interdorsal space; its height 1.1 in its base length; its apex well rounded and its free rear tip bluntly pointed; its anterior margin long and slightly convex; its posterior margin linear. Second dorsal fin considerably smaller than first dorsal fin; its origin above anterior 1/3 of anal fn base; base length 1.4 in anal fin base length; its height 1.6 in its base length; apex well rounded and its free rear tip well pointed; its anterior margin long and slightly convex; its posterior margin slightly concave. Pelvic fin about as large as first dorsal fin in area; its origin located just at center of body; its insertion below middle of first dorsal fin base; its base length 0.8 in first dorsal fin base length; its apex broadly rounded; its free rear tip bluntly pointed; its inner margin linear. Anal fin larger than second dorsal fin; its origin below posterior 1/3 of interdorsal space; its insertion opposite to second dorsal fin insertion; its base length slightly shorter than interdorsal space; its height 1.7 in its base length; its apex well rounded and its free rear tip well pointed; its anterior margin long and convex; its posterior margin concave; its inner margin linear. Caudal fin with a moderately developed lower lobe and a distinct subterminal notch; no enlarged dermal denticles on its dorsal and preventral margin; ventral and posterior tip rounded; terminal and subterminal margin linear.
Teeth: number of upper jaw teeth 68, lower jaw teeth 78 (Teng, 1962). All teeth same, with 3 (infrequently 5) cusps, principal cusp large and long; no symphyseal tooth on upper jaw, but three small teeth on lower jaw symphysis (Teng, 1962).
Dermal denticles: dermal denticles on lateral side of body above pectoral fin thick with three cusps; principal cusp longest, lateral cusps indistinct; three strong ridges running from base toward each cusp; some weak ridges running among strong ridges.
Vertebrae: monospondylous vertebrae 45, precaudal diplospondylous vertebrae 34 (precaudal vertebrae 79).
Spiral valves: unknown
Egg cases: two egg shells present; shape rectangular, with long tendrils on four corners; anterior projections widely separate; posterior ends curving closer each other; surface of shell smooth; lateral margins with remarkable wavy ridges on lateral margins at middle half, and anterior and posterior parts (from Teng, 1962).
Color. Teng (1962) described that about ten dark brownish transverse bands are present on dorsal and lateral sides of body, but these bands had already faded away from the holotype, when the second author Inoue examined the holotype in 2002. However, Teng’s original figure clearly indicates four broad and distinct saddle blotches before first dorsal fin, i.e. first saddle blotch at posterior part of eye and postorbital region, second saddle over gill opening region, third one above inner margin of pectoral fin, and fourth one above origin of pelvic fin. The figure also shows wide saddle blotches, one on first dorsal fin, one on second dorsal fin, and two saddles on caudal fin. In addition, a narrow saddle band is seen between third and fourth saddle blotches and one on caudal peduncle. Numerous small white spots and a few small dark spots were recognized in 2002, as indicated in the original figure.
Size. Size at maturation less than 655 mm TL (female). Maximum size at least 655 mm TL (female).
Distribution. Off Dong-gang, western South Taiwan; about 200 fathoms (Teng, 1962).
Remarks. Cephaloscyllium formosanum and C. umbratile were synonymized under C. isabellum (Bonnaterre, 1788) without any reason by Springer (1979). Compagno (1984, 1988) followed Springer’s opinion. Compagno (1988) also mentioned that C. umbratile and C. formosanum are probably the same species, but Compagno (1999) considered C. isabellum and C. umbratile to be different species. Recently Schaaf-da Silva & Ebert (2008) reviewed the western North Pacific swellsharks, and they also considered C. umbratile as distinct from C. isabellum, and treated C. formosanum as a junior synonym of C. umbratile, following previous workers.
As shown above, Cephaloscyllium formosanum is currently considered as a junior synonym of C. umbratile, but the validity of C. formosanum has never been studied before. Here we discuss its validity, based on comparisons of the holotypes of C. formosanum and C. umbratile, and many specimens of C. umbratile.
The holotype of Cephaloscyllium formosanum was examined by Inoue in 2002, and the measurements and other morphological information were taken from the holotype. A part of the morphological information of the holotype of C. umbratile was taken from Schaaf-da Silva & Ebert (2008), though their morphometric data were not used, because the holotype is a stuffed dried specimen (SU 12693).
Morphometric data of these two species are almost overlapping in the holotype of Cephaloscyllium formosanum and specimens of C. umbratile (Table 4). The vertebral counts are also overlapping in precaudal diplospondylous vertebrae (34 in C. formosanum, 30–40 in C. umbratile), but are somewhat different in monospondylous vertebrae (45, 47–54).
The coloration can be diagnostic in this genus, and the number and position of the broad saddle blotches before first dorsal fin are consistent and species specific in the genus Cephaloscyllium. The broad saddle blotches before first dorsal fin are four in C. formosanum, but three in C. umbratile (Figures 7 and 8). The position of second saddle blotch is over gill opening region in C. formosanum, but it is always over pectoral fin base in C. umbratile. The third saddle blotch is located above inner margin of pectoral fin in C. formosanum, but it is at middle of pectoral and pelvic fins in C. umbratile. The fourth saddle blotch is positioned above pelvic fin origin in C. formosanum, but it is on first dorsal fin in C. umbratile.
The holotype of Cephaloscyllium formosanum (655 mm TL) has egg cases, and this species is already mature at a length of 66 cm TL. However, the females of C. umbratile are still immature at this size, and get mature at 921–1040 mm TL (Taniuchi, 1988). Therefore, C. formosanum is rather a smaller species than C. umbratile. In addition, the margins of the egg case are remarkably wavy in C. formosanum (Teng, 1962), but the margins of the egg cases are smooth in C. umbratile.
These facts indicate that Cephaloscyllium formosanum is apparently distinct from C. umbratile, and therefore C. formosanum Teng, 1962 is resurrected here.
description: Published as part of Nakaya, Kazuhiro, Inoue, Shinsuke & Ho, Hsuan-Ching, 2013, A review of the genus Cephaloscyllium (Chondrichthyes: Carcharhiniformes: Scyliorhinidae) from Taiwanese waters, pp. 101-129 in Zootaxa 3752 (1) on pages 122-126, DOI: 10.11646/zootaxa.3752.1.8, http://zenodo.org/record/222530