Cephaloscyllium umbratile

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 : 116-122

Cephaloscyllium umbratile Jordan & Fowler, 1903

English name: Japanese swellshark Taiwanese name: Tou-sa

Japanese name: Nanukazame

( Figures 7–8 , Table 3 )

Cephaloscyllium umbratile Jordan & Fowler, 1903, pp. 602–603, fig. 1; Fowler, 1941, pp. 32–33; Nakaya, 1975, pp. 9–14, figs. 1–3; Nakaya in Okamura et al., 1984, pp. 38–39; Shen, 1984, p. 2, pl. 2 (4–3); Yamada et al., 1986, p. 8; Amaoka et al., 1995, p. 16; Nakaya, 1997, pp. 41–42; Compagno et al., 2005, p. 218; Schaaf-da Silva & Ebert, 2008, pp. 15–21; Shen & Wu, 2012, p. 64; Ebert et al., 2013, p. 331, pl. 43.

Cephaloscyllium isabellum: Chen & Joung in Shen et al., 1993, p. 54, pls. 5–8.

Cephaloscyllium sp.: Compagno et al., 2005, p. 222.

Galeus eastmani: Shen, 1984 , p. 2, plate 2 (4–2).

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

Material examined. Taiwan: NMMB-P10849, male 593 mm TL (Nan-fang-ao, Yilan). NMMB P-15466, 2 males, 325–425 mm TL (Da-xi, Yilan). NMMB-P16168, male, 195 mm TL (Da-xi, Yilan). NMMB-P 16199, female, 230 mm TL; NMMB-P 16201, female, 203 mm TL; NMMB-P16462, 2 females, 210–260 mm TL; NMMB P-16618, 1 male, 321 mm TL, 2 females, 313–317 mmTL (Nan-fang-ao, Yilan). NMMB P-17180, female, 217 mm TL; NMMB-P 17183, female, 193 mm TL (Ke-tzu-liao, Kaohsiung). NMMB-P 17184, female, 215 mm TL; NMMB P- 17185, female, 217 mm TL (Da-xi, Yilan). HUMZ 170361, female, 412 mm TL; HUMZ 170370, female, 214 mm TL; HUMZ 170372, female, 254 mm TL; HUMZ 170373, male, 398 mm TL; HUMZ 170374, female, 186 mm TL; HUMZ 170375, female, 218 mm TL; HUMZ 170376, male, 192 mm TL; HUMZ 170384, female, 332 mm TL; HUMZ 170471, female, 348 mm TL; HUMZ 170472, male, 315 mm TL; HUMZ 170473, female, 303 mm TL; HUMZ 170474, female, 265 mm TL; HUMZ 170475, female, 215 mm TL; HUMZ, 170476, male, 186 mm TL; HUMZ 170477, male, 193 mm TL; HUMZ 170478, female; HUMZ 170479, male, 240 mm TL; HUMZ 170480, female, 194 mm TL; HUMZ 170481, male, 318 mm TL; HUMZ 170966, male, 253 mm TL; HUMZ 170967, female, 436 mm TL; HUMZ 170968, male, 351 mm TL; HUMZ 171371, male, 181 mm TL; HUMZ 213790, male, 798 mm TL; HUMZ 213791, male, 813 mm TL (Da-xi, Yilan). Other regions: HUMZ 35478, male, 298 mm TL; HUMZ 80127, male, 306 mm TL; HUMZ 58698, female, 279 mm TL; HUMZ 39370, male, 430 mm TL; HUMZ 39371, male, 307 mm TL; HUMZ 49478, male, 240 mm TL; HUMZ 80496, female, 268 mm TL; HUMZ 80497, male, 293 mm TL; HUMZ 110107, male, 346 mm TL; HUMZ 121953, male, 444 mm TL; HUMZ 35074, male, 266 mm TL ( Kochi, Japan). HUMZ 65593, female, 249 mm TL; HUMZ 65992, female, 236 mm TL; HUMZ 65993, male, 244 mm TL; HUMZ 66180, male, 702 mm TL; HUMZ 66181, female, 417 mm TL; HUMZ 66227, male, 237 mm TL (Ishikawa Pref., Japan). HUMZ 50000, male, 564 mm TL (off Usujiri, Hokkaido Pref., Japan). HUMZ 39379, female, 377 mm TL; HUMZ 39439, female, 371 mm TL (Kii Strait, Japan). HUMZ 39434, female, 331 mm TL (Kagoshima Pref., Japan). HUMZ 95268, female, 896 mm TL; HUMZ 95269, male, 948 mm TL (27º57.7’N, 127º59.7’E). HUMZ 117826, male, 845 mm TL (Wakayama Pref., Japan). HUMZ 138270, male, 296 mm TL; HUMZ 138597, female, 259 mm TL (Yamagata Pref., Japan). HUMZ 178907, female, 948 mm TL; HUMZ 178908, male, 962 mm TL; HUMZ 178909, male, 938 mm TL; HUMZ 178910, male, 980 mm TL; HUMZ 178911, female, 889 mm TL; HUMZ 178912, female, 1011 mm TL (Shimane Pref., Japan). HUMZ 39471, female, 243 mm TL; HUMZ 121950, male, 294 mm TL; HUMZ 122689, female, 487 mm TL (locality unknown). FAKU 1012, female, 225 mm TL; FAKU 23818, male, 302 mm TL; FAKU K1261, female, 245 mm TL (Mie Pref., Japan). FAKU 58914, male, 550 mm TL (Kyoto Pref., Japan). TMFE 12776, male, 216 mm TL; TMFE 12786, female, 204 mm TL; TMFE 12789, female, 232 mm TL; TMFE 12791, female, 246 mm TL; TMFE 12797, female, 261 mm TL; TMFE 12860, female, 286 mm TL; TMFE 12890, male, 213 mm TL; TMFE 12921, female, 270 mm TL; TMFE 13324, female, 451 mm TL; TMFE 13592, female, 375 mm TL; TMFE 13606, male, 218 mm TL; TMFE 13607, male, 187 mm TL; TMFE 14024, male, 376 mm TL; TMFE 14027, male, 401 mm TL; TMFE 14052, female, 300 mm TL; TMFE 14053, male, 228 mm TL; TMFE 14065, female, 293 mm TL (Shizuoka Pref., Japan).

Diagnosis. Three broad dark saddle blotches before first dorsal fin; first saddle on posterior half of interorbital region and immediately behind eye, second saddle over pectoral fin base, third saddle at middle between pectoral and pelvic fin bases. Adults with dark and irregular spots and sometimes with white spots between the saddles. Large species maturing at about 950 mm TL and attaining 1145 mm TL.

Description. Body slender in young, stout in adults ( Figure 7 ). Head large, broad and well depressed. Trunk robust, tail slender. Caudal peduncle rather slender; length about 1.5 times its height. Caudal fin axis a little elevated.

Snout short, its tip slightly pointed, dorsal side flat. Interorbital area flat, shallowly concave in larger specimens. Nostrils closer to mouth than to snout tip. Anterior nasal flap well developed, extending as a definite lobe, with a distinct notch on its posterior margin; flap not reaching mouth. Posterior nasal flap developed. Internarial space wide, its length greater than nostril width. Mouth very wide and high; width nearly three times preoral length (without teeth); lower jaw almost straight along the side with a flat 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; apex and free rear tip moderately rounded; posterior margin about linear in adult and well convex in young. First dorsal fin origin before center of body in young, behind it in adult; origin above anterior 1/3 to middle of pelvic base; base length shorter than pelvic-anal fin space; apex well rounded and free rear tip slightly rounded; anterior and posterior margin linear in adult and well convex in young. Second dorsal fin considerably smaller than first dorsal fin; origin above anterior 1/4 of anal fin base; base much shorter than anal fin base; apex well rounded; free rear tip bluntly pointed; its anterior margin slightly convex; posterior margin linear or slightly concave. Pelvic fin insertion below middle of first dorsal fin 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 longer than anal-lower caudal space; apex well rounded; its free rear tip pointed; anterior margin long and convex; posterior margin linear or slightly concave. Caudal fin slender, with a moderately developed lower lobe and a distinct subterminal notch; no enlarged dermal denticles on its dorsal and preventral margin; terminal and subterminal margin linear in adult and well rounded in young.

Teeth: number of teeth on both jaws high; upper jaw 77–110, lower jaw 71–102; teeth with 3–5 cusps, principal cusp longest with a few smaller cusps on both sides; teeth near symphysis on both jaws large and symmetrical; lateral teeth smaller and more asymmetrical toward side of jaws.

Dermal denticles: dermal denticles on lateral side of body above pectoral fin thick with 1–3 cusps; lateral cusps small, indistinct; three strong ridges running from base toward each cusp.

Vertebrae: monospondylous vertebrae 47–54, precaudal diplospondylous vertebrae 30–40, precaudal vertebrae 79–91.

Spiral valves: 9–12.

Specimens Male Female

(n=41) (n=45) ...... continued on the next page

Color. Ground body color brownish dorsally, pale ventrally. Seven dark brown and wide saddle blotches on body; first saddle on posterior half of interorbital region and immediately behind eye, second saddle over pectoral fin base, third saddle at middle between pectoral and pelvic fin bases, 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. Saddles sometimes surrounded by whitish lines. Dorsal sides of pectoral and pelvic fins uniformly light brownish. Specimens larger than about 350 mm TL ( Figures 7 , 8 f–g) with many dark irregular spots and some white spots on dorsal side of body, dorsal fins and caudal fin, with dark grayish stains and blotches on ventral side of body.

Size. Size at maturation 961– 960 mm TL (male), 921–1040 mm TL (female) (Taniuchi, 1988). Maximum size 1140 mm TL (male), 1145 mm TL (female) (Taniuchi, 1988).

Distribution. Western North Pacific Ocean, including Japan Sea, East China Sea ( Japan, Korea, China and Taiwan); 90–200 m (Taniuchi, 1988), 200–500 m (Ho, pers. obs.).

Remarks. Cephaloscyllium umbratile was described based on a specimen collected at Nagasaki, Japan, and was recognized as a distinct species by Nakaya (1975). Later, Springer (1979) treated C. umbratile as a junior synonym of C. isabellum . Compagno (1984, 1988) followed Springer (1979) with a question mark. However, all the recent workers such as Compagno (1999), Compagno et al. (2005), and Schaaf-da Silva & Ebert (2008) treat C. umbratile as a distinct species, with which we agree.

The measurements and meristic counts do not work well as distinguishing characters in many cases, but the body coloration can be a good diagnostic character of the species in this genus. Figures 7 and 8 show ontogenetic color changes of Cephaloscyllium umbratile in specimens between 185 mm TL to 845 mm TL. One of the consistent diagnostic characters for C. umbratile is the number and position of dorsal saddle blotches. As shown above, seven dark brown and broad saddle blotches are present on body. First saddle blotch is located on posterior half of interorbital region and immediately behind eye, second saddle is positioned over pectoral fin base, third saddle at middle between pectoral and pelvic fin bases, fourth saddle on first dorsal fin, fifth saddle on second dorsal fin, and sixth and seventh saddles are located on posterior half of caudal fin. These characters are very consistent throughout life in C. umbratile . Dark stains appear on dorsal side of body and fins with growth. Blunt whitish lines tend to encircle dark saddle blotches, and to be broken into paler dots, or disappear, with growth.

Cephaloscyllium umbratile is clearly characterized and can be distinguished from other species in western North Pacific species by presence of three dark broad saddle blotches before first dorsal fin, and the position of second and third saddle blotches. For more information about consistency of saddle blotches, see discussions of other species and general discussion.

Figures

FIGURE 7. Cephaloscyllium umbratile from Taiwan (A) and Japan (B). A, HUMZ 213790, male, 798 mm TL collected at Daxi, Taiwan; B, HUMZ 117826, male, 845 mm TL, collected at Wakayama, Japan. Arabic numerals show saddle blotches before first dorsal fin.

FIGURE 8. Dorsal views of Cephaloscyllium umbratile, showing color pattern changes with growth. A, NMMB-P 17185, female, 185 mm TL; B, NMMB-P 17184, female, 210 mm TL; C, NMMB-P 16462, female, 255 mm TL; D, NMMB-P 15618, male, 315 mm TL; E, NMMB-P 15466, male, 325 mm TL; F, NMMB-P 15466, male, 425 mm TL; G, NMMB-P 10849, male, 593 mm TL.

Tables

TABLE 3. Proportional measurements and counts of Cephaloscyllium umbratile.

Total length (mm) Proportion (%TL)	TOT	Min 192.2	Max 979.5	Mean 421.5	Min 185.8	Max 1011.1	Mean 355.8
Precaudal length (%) Precaudal length to lower origin (%) Prenarial length Prenarial length from inner nostrils	PRC PRC lower PRN PRN inner	70.9 69.5 2.2 3.4	79.8 78.7 3.3 3.6	74.7 73.4 2.8 3.5	68.8 68.0 2.2 3.5	79.7 78.3 3.7 4.5	74.0 72.5 2.9 3.8
Preoral length Preorbital length Prespiracle length	POR POB PSP	2.6 4.5 8.6	5.2 7.1 11.7	4.1 5.6 9.7	3.2 4.8 8.3	5.3 7.6 11.6	4.3 5.7 9.9
Prebranchial length Pre 5th branchial length	PG1 PG5	14.0 16.9	17.4 22.8	15.4 19.8	14.1 17.8	16.9 21.7	15.6 19.8
Prepectoral length Prepelvic length Snout-vent length	PP1 PP2 ???	16.2 37.9 48.7	20.2 50.9 50.6	18.4 43.9 49.5	16.2 38.1 45.6	20.5 50.7 48.3	18.4 43.5 47.2
Vent-caudal length Preanal length Pre-first dorsal fin length Pre-second dorsal fin length	??? PAL PD1 PD2	49.7 55.5 42.6 57.9	51.4 67.6 54.8 69.8	50.6 60.7 48.4 63.2	49.8 52.0 43.1 57.3	53.0 67.1 54.0 69.1	51.8 59.5 47.5 62.5
Interdorsal space length Dorsal-caudal length Pectoral-pelvic length	IDS DCS PPS	6.5 5.2 13.5	8.8 8.7 23.5	7.8 6.8 18.2	6.6 5.1 13.9	9.3 9.1 23.8	7.9 7.0 17.9
Pelvic-anal space Anal-caudal length	PAS ACS	8.5 4.4	11.6 7.5	10.3 5.8	7.5 4.8	10.2 7.3	9.0 5.9
Eye length Eye height Interorbital space	EYL EYH INO	2.7 7.1	3.9 8.6	3.1 7.7	2.7 0.4 7.2	4.0 0.9 8.5	3.2 0.6 7.8
Nostril width Internarial space Spiracle length Mouth length	NOW INW SPL MOL	2.1 2.3 0.5 3.3	3.2 3.5 0.8 6.3	2.6 2.8 0.6 4.2	2.2 2.4 0.4 3.2	3.5 3.7 0.8 5.7	2.7 2.9 0.6 4.1
Mouth width First gill height Second gill height	MOW GS1 GS2	7.3 1.1 1.7	12.4 2.4 2.3	9.9 1.8 2.0	7.3 1.2 1.3	12.7 2.6 2.0	9.7 1.8 1.6
Third gill height Fourth gill height	GS3 GS4	1.7 1.7	2.3 2.3	2.0 2.0	1.3 1.3	2.0 2.0	1.6 1.6
Fifth gill height Head height Head width	GS5 HDH HDW	0.8 5.7 10.9	2.0 10.5 18.3	1.2 7.8 14.3	0.5 5.4 11.4	1.8 14.2 19.0	1.1 7.7 14.2
Trunk height Trunk width Caudal peduncle height Caudal peduncle width	TRH TRW CPH CPW	7.5 9.4 3.0 2.8	14.4 18.6 3.5 3.3	10.0 12.8 3.2 3.1	6.3 8.8 3.2 2.7	11.3 18.2 3.7 3.1	9.1 12.6 3.5 2.9