Cephaloscyllium sarawakensis Yano, Ahmad & Gambang, 2005

Nakaya, Kazuhiro, Inoue, Shinsuke & Ho, Hsuan-Ching, 2013, A review of the genus Cephaloscyllium (Chondrichthyes: Carcharhiniformes: Scyliorhinidae) from Taiwanese waters, Zootaxa 3752 (1), pp. 101-129 : 110-116

publication ID

https://doi.org/ 10.11646/zootaxa.3752.1.8

publication LSID

lsid:zoobank.org:pub:7485882A-6CED-494E-BFDF-F7BCA76DF94B

DOI

https://doi.org/10.5281/zenodo.6157448

persistent identifier

https://treatment.plazi.org/id/03F67E43-FFB5-0444-FF57-61CBFEA4FD3B

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Plazi

scientific name

Cephaloscyllium sarawakensis Yano, Ahmad & Gambang, 2005
status

 

Cephaloscyllium sarawakensis Yano, Ahmad & Gambang, 2005 View in CoL

English name: Sarawak pygmy swellshark Taiwanese name: Sa-lao-yue-tou-sa

( Figures 4–6 View FIGURE 4 View FIGURE 5 View FIGURE 6 , Table 2 View TABLE 2 )

Cephaloscyllium sarawakensis Yano, Ahmad & Gambang, 2005 , p. 147, pls. 92–101; Ebert et al., 2013, p. 328, pl. 44.

Cephaloscyllium umbratile: Teng, 1962 , p. 45, fig. 10; Chen, 1963, p. 29, fig. 9; Chan, 1966, p. 229, fig. 5, 7, pl. 2; Bessednov, 1969, p. 27, figs. 9, 10; Chen et al., 1997, p. 2, fig. 5.

Cephaloscyllium sufflans: Fourmanoir & Nhu-Nhung, 1965 , p. 13, fig. 1.

Cephaloscyllium formosanum: Shen, 1984 , p. 2, pl. 2 (4-4 a, b).

Cephaloscyllium isabellum (in part as pseudo- umbratile ): Compagno, 1984, p. 298.

Cephaloscyllium sp. (in part): Compagno, 1988, p. 115; Compagno et al., 2005: p. 222, pl. 36.

Cephaloscyllium circulopullum Yano, Ahmad & Gambang, 2005 , p. 159, pls. 102–105.

Cephaloscyllium parvum Inoue & Nakaya, 2006 , p. 77, figs. 1–3.

Material examined. Taiwan: ASIZP 53881, male, 325 mm TL (Dong-gang). HUMZ 114179, male, 142 mm TL; HUMZ 114180, male, 164 mm TL; HUMZ 114181, male, 218 mm TL; HUMZ 170770 (paratype of C. parvum ), male, 166 mm TL (Kaohsiung). NMMB-P6104, a female, 143 mm TL, 5 males, 151–197 mm TL ( Taiwan). NMMB-P 6597 (formerly THUP 616), female, 278 mm TL (Kaohsiung). NMMB-P 6604 (formerly THUP 1666), male, 334 mm TL (Dong-gang, Pingtung). NMMB-P 6608 (formerly THUP 2537-8), 1 male, 200 mm TL, 1 female, 212 mm TL (Dong-gang, Pingtung). NMMB-P 6617 (formerly THUP 2211), female, 173 mm TL (Donggang, Pingtung). NMMB-P 17476, female, 162 mm TL (Ke-tzu-liao, Kaohsiung). NMMB-P 17134, male, 159 mm TL (Ke-tzu-liao, Kaohsiung, Da-xi). NMMB-P 17136, female, 246 mm TL (Ke-tzu-liao, Kaohsiung, Da-xi). NMMB-P 17138, male, 155 mm TL (Ke-tzu-liao, Kaohsiung, Da-xi). NMMB-P 17139, male, 156 mm TL (Ke-tzuliao, Kaohsiung, Da-xi). NMMB-P 17141, male, 212 mm TL (Ke-tzu-liao, Kaohsiung, Da-xi). NMMB-P 17182, female, 192 mm TL (Ke-tzu-liao, Kaohsiung, Da-xi). NMMB-P uncat. (HO-375), female, 263 mm TL (Ke-tzuliao, Kaohsiung). TFRI 3080, female, 395 mm TL ( Taiwan). TFRI 3359, female, 441 mm TL ( Taiwan). Other regions: HUMZ 109126 (holotype of C. parvum ), male, 397 mm TL; HUMZ 109124 (paratype of C. parvum ), female, 406 mm TL; HUMZ 109125 (paratype of C. parvum ), female, 377 mm TL; HUMZ 109127 (paratype of C. parvum ), male, 349 mm TL (off Sarawak, Borneo Island, Malaysia). FAKU 100088, female, 378 mm TL (Gulf of Tongking, southern China). NMMB-P 13578, female, 375 mm TL (Nha Trang, Vietnam). NMMB-P 13579, male, 182 mm TL (Nha Trang, Vietnam).

Diagnosis. Two distinct and wide dark brown saddle blotches before first dorsal fin in adults. Juveniles with three saddle blotches before first dorsal fin. First saddle immediately behind eye, second saddle over posterior 1/3 of base and inner margin of pectoral fin, and third saddle a little before first dorsal fin, which fades with growth. Dark lateral circular to oblong blotches present above gill openings and on lateral side of trunk. Young individuals with many polka dots on body and fins. Anterior nasal flap triangular without an elongate flap. Small species maturing at about 35 cm TL and attaining at least 44 cm TL.

Description. Proportional measurements and meristic counts are given in Table 2 View TABLE 2 .

Body thick and stout ( Figure 4 View FIGURE 4 ). Head large and rather rounded. Trunk and tail rather thick. Caudal peduncle short and thick; length almost equal to its height. Caudal fin axis a little elevated.

Snout long, its tip rounded, dorsal side rather convex. Interorbital area flat slightly convex. Nostrils closer to mouth than to snout tip. Anterior nasal flap triangular without notch on its posterior margin, not extending as a definite lobe; flap not reaching mouth. Posterior nasal flap well developed. Internarial space narrow; its length shorter than nostril width. Mouth narrow and low; width less than two times preoral length (without teeth); lower jaw arched with evenly rounded symphysis. Labial furrows completely absent from both jaws. Eye small, slender. Spiracle small, behind and slightly below eye. Gill openings short; 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 linear in adult, and convex in young. First dorsal fin origin located before or at about center of body; its origin above anterior 1/3 of pelvic base; base length about equal to pelvic-anal fin space; apex and free rear tip rounded; posterior margin linear or slightly concave in adult and well convex in young. Second dorsal fin considerably smaller than first dorsal fin; its origin above anterior 1/3 of anal base; base shorter than anal fin base; apex broadly rounded; free rear tip slightly pointed. Pelvic fin insertion below posterior 1/3 of first dorsal base; apex broadly rounded. Anal fin larger than second dorsal fin; its origin below posterior 1/3 of interdorsal space; insertion opposite to second dorsal fin insertion; base length longer than anal-lower caudal space; apex broadly rounded; free rear tip pointed; posterior margin linear or slightly concave in adult and well rounded in young. Caudal fin wide and relatively large, with a developed lower lobe and a distinct subterminal notch; no enlarged dermal denticles on its dorsal and preventral margin; terminal and subterminal margin linear or slightly convex in adult and well rounded in young.

Teeth: number of teeth on both jaws relatively fewer; upper jaw 54-68, lower jaw 60-63; teeth with 3 (infrequently 4) cusps, principal cusp largest and longest with a few smaller cusps on both sides; teeth near symphysis on both jaws symmetrical; lateral teeth more asymmetrical toward side of jaws.

Dermal denticles: dermal denticles on lateral side of body above pectoral fin thick and leaf-like, with one cusp (infrequently one cusp with indistinct lateral cusps) and with 3–5 strong ridges running from base toward apex of each cusp.

Vertebrae: monospondylous vertebrae 37–42, precaudal diplospondylous vertebrae 26–33, precaudal vertebrae 63–72.

Spiral valves: 7–8.

Color. (1) Specimens less than ca. 17 cm TL ( Figures 5 View FIGURE 5 a–d). Ground body color brownish dorsally, pale to slightly grayish ventrally. Ventral side of head usually uniform, slightly dark marginally with some spots, sometimes heavily spotted on ventral sides of head, body and fins (NMMB P-17139). Seven dark brown and wide saddle blotches on body; first saddle immediately behind eye, second saddle over posterior 1/3 of pectoral fin base and inner margin, third saddle a little before first dorsal fin, fourth saddle on first dorsal fin, fifth saddle on second dorsal fin, sixth saddle on caudal fin just behind caudal peduncle, and seventh saddle on posterior half of caudal fin. Each saddle with a blackish area surrounded by a white line; first and second saddles with a blackish transverse band surrounded by a thin white line; third saddle with a blackish circular spot; fourth and fifth saddles with a pair of black circular spots on both sides of the fins. A dark and large lateral blotch between pectoral and pelvic fins. A distinct blackish circular blotch above gill opening region. Many smaller dark circular spots in polka-dot pattern present on dorsal sides of head, body, dorsal sides of pectoral and pelvic fins, dorsal fins and caudal fin.

...... continued on the next page Pelvic fin length P2L 8.7 10.4 9.8 9.1 11.9 11.0 9.8 9.8

1from Yano et al. (2005),2 from Inoue & Nakaya (2006) (2) Specimens between ca. 17–30 cm TL ( Figures 5 View FIGURE 5 e–h, Figure 6 View FIGURE 6 ). Color patterns become obscure with growth. Polka-dot color pattern fainter with growth. Third and seventh saddle blotches getting fainter with growth. A semi-circular to vertically elliptical dark lateral blotch between pectoral and pelvic fins, and a dark blotch above gill openings present ( Figure 6 View FIGURE 6 ). White lines surrounding spots and bands fainter with growth.

(3) Specimens larger than ca. 30 cm TL ( Figure 4 View FIGURE 4 ). Polka-dot color pattern completely lost. Only five wide saddle blotches present on body, i.e. first and second saddles before first dorsal fin, third saddle obscure, fourth to sixth saddles on dorsal fins and caudal fin, and seventh saddle faint and small. A large semi-circular to vertically elliptical dark lateral blotch present between pectoral and pelvic fins. A smaller dark blotch above gill openings. White lines surrounding spots and bands completely lost.

Size. Size at maturation less than 325 mm TL in male, less than 354 mm TL in female (Yano et al., 2005). Maximum size at least 397 mm TL in male, 441 mm TL in female (Inoue & Nakaya, 2006).

Distribution. South China Sea (western South Taiwan, Hong Kong, Gulf of Tongking, Vietnam, Malaysia); 118– 165 m (Yano et al., 2005), 45–91 fathoms (Chan, 1966), 100–200 m (Ho, pers. obs.).

Remarks. Cephaloscyllium sarawakensis and C. circulopullum were described by Yano et al. (2005), based on specimens collected from Sarawak, in a book of limited distribution. Inoue & Nakaya (2006) described C. parvum based on specimens collected from Sarawak, Taiwan and China. Later, Schaaf-da Silva & Ebert (2008) treated C. parvum as a junior synonym of C. sarawakensis , with which we agree.

Yano et al. (2005, p. 153) gave four characters for distinguishing Cephaloscyllium circulopullum from C. sarawakensis : position of the first dorsal fin origin, length from snout tip to pectoral origin, mouth width, and shape of dark blotch on center of body side between pectoral and pelvic fins.

Yano et al. (2005, p. 153) described the first dorsal fin origin in Cephaloscyllium circulopullum as located above “half of pelvic fin base”, but that it is located “about opposite pelvic fin origin or in front of it” in C. sarawakensis . All the specimens used in this study (32 specimens in total), including type specimens of C. parvum , which is now a junior synonym of C. sarawakensis , have first dorsal fin origin above anterior 1/3 (holotype of C. parvum ) or almost at level of middle pelvic fin base, never opposite or before pelvic fin origin. The origins of the first dorsal fins shown in the original figures (pls. 92, 93, 95 and 96) are also apparently behind pelvic fin origins, or above pelvic fin bases, just like those of C. circulopullum . Therefore, the relative position of the first dorsal fin origin and pelvic fin base can not be a distinguishing character of C. circulopullum and C. sarawakensis .

Length from snout tip to pectoral origin (20.6% TL and 21.5% TL in Cephaloscyllium circulopullum vs. 17.2– 19.4% TL in C. sarawakensis in the original descriptions) also can not be a distinguishing character, because the range is widened (16.1–21.3% TL) for C. sarawakensis by inclusion of specimens from Taiwan, as well as the type and additional specimens of C. parvum .

The mouth widths of Cephaloscyllium circulopullum (8.5% TL and 8.8% TL) are completely included within the range of C. sarawakensis (8.2–10.3% TL) in the original description.

The shape of dark blotch on lateral side of body between pectoral and pelvic fins was described as “almost circle” for Cephaloscyllium circulopullum and “vertical elongate” for C. sarawakensis . As shown in the discussion of C. fasciatum , it is almost impossible to describe a new species for the genus Cephaloscyllium without taking vast intraspecific color variation into consideration. For example, the lateral loops on body side are greatly variable in C. fasciatum , i.e. triangular, quadrangular, polyangular, circular, elliptical and combination of these. Actually, semi-circular to vertically elongate blotches were found in the specimens examined ( Figure 6 View FIGURE 6 ). Therefore, we consider that the characters “almost circle” and “vertical elongate” simply represent color variations within C. sarawakensis .

Accordingly, the distinguishing characters used in the original descriptions are invalid, and as no other characters are available for the species distinction, C. circulopullum is considered as a junior synonym of C. sarawakensis .

TABLE 2. Proportional measurements and counts of Cephaloscyllium sarawakensis, C. parvum and C. circulopullum.

Species C. sarawakensis C. parvum 2 C. circulopullum 1
  Taiwan specimens Type specimens (n=16) (n=6)1 Type specimens (n=5) holotype paratype
  Min Max Mean Min Max Mean Min Max Mean
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