Cephaloscyllium pardelotum, Schaaf-Da, Jayna A. & Ebert, David A., 2008

Schaaf-Da, Jayna A. & Ebert, David A., 2008, A revision of the western North Pacific swellsharks, genus Cephaloscyllium Gill 1862 (Chondrichthyes: Carcharhiniformes: Scyliorhinidae), including descriptions of two new species, Zootaxa 1872, pp. 1-28 : 3-7

Cephaloscyllium pardelotum sp. nov.

( Figs. 1 , 5 a, 7a; Table 1 )

Type Series and Locality. Holotype, CAS 224876, female, 202 mm TL, collected from Tungkang, Taiwan, 22°27.6'N, 120°26.4'E, collected by David A. Ebert on 21 April 1988, in excellent condition.

Diagnosis. Body comparatively slender, head short, pre-first dorsal length 48% TL. Mouth wide, its width 0.53 in head length. Snout very short, moderately flattened, broadly rounded; anterior nasal flaps not overlapping mouth posteriorly, narrowly lobate, inner margin with a deep notch. First dorsal fin relatively small; considerably larger than second dorsal fin; originates behind half of pelvic-fin base. Pectoral fins relatively large and broad; anal fin relatively large. Color pattern elaborate; speckled dorsal saddles; three lateral clusters of spots arranged into rosettes between paired fins; dark lateral blotch between paired fins absent.

Description. Proportional dimensions in percentage of TL are shown in Table 1 . Head short, its length 0.27 times in precaudal length; pre-pectoral length 18.3% TL. Snout moderately flattened, broadly rounded, and short, preorbital length 0.30 times head length; 0.72 times interorbital width. Eye small, its horizontal eye length 0.19 in head length; cat-like. Spiracle small, its diameter 0.27 times horizontal eye length. Gill openings very small, vertical length of first gill opening 0.09 in head length. Mouth relatively small, its width 0.53 times head length; labial furrows absent. Nostrils large; internarial distance 0.24 in mouth width; anterior nasal flaps elongate, lobed, with deep notch on inner margin, not overlapping mouth posteriorly. First dorsalfin small; first dorsal-fin height 0.40 in length; origin about opposite or behind half of pelvic-fin base; pre-first dorsal length 48.0% TL. Second dorsal fin small, only slightly smaller than first; second dorsal-fin height 0.36 in length; pre-second dorsal length 0.84 times precaudal length; second dorsal-fin height 0.71 in first dorsalfin height. Pectoral fins relatively large and broad; anterior margin 0.63 times head length; base 0.72 in anterior margin. Pelvic fin small; its length 0.14 times precaudal length; base 0.66 in length. Anal fin relatively large; its height 0.05 times precaudal length and its length 0.14 times precaudal length; larger than either dorsal fin; second dorsal-fin height 0.71 in anal-fin height; first dorsal-fin height about equal to anal-fin height. Caudal fin broad, asymmetrical, with subterminal notch; dorsal-lobe length 0.37 times precaudal length; ventral-lobe length 0.35 in dorsal-lobe length.

Body firm, thick-skinned, with well calcified dermal denticles; no ridge of enlarged denticles along dorsal caudal-fin margin. Teeth very small and numerous; similar in both jaws; three cusps in females. Total vertebrae 120, monospondylous 44, precaudal 74, and pre-caudal diplospondylous 30.

Size and sexual maturity. Unknown at present.

Coloration. Background color golden to light brown dorsally; pale ventrally; small brown specks cover dorsal and lateral surfaces; dark lateral blotch between paired fins absent. Seven dorsal H-shaped saddles clearly defined; first in line with the gills, second above pectoral-fin insertion, third just before pelvic-fin origin, then one at each dorsal-fin base, one at caudal-fin origin, and dorsal-caudal lobe; saddles open, outline brown and variegated, not dark and solid. Rosette pattern present, consisting of a circle of 5–6 small brown speckles; three rosettes present laterally between the pectoral and pelvic fins; rosettes on head include one behind each orbit, one between orbits, one over each gill series, and a few on snout; each paired fin has one rosette placed dorsally, larger rosettes on larger fins; paired rosettes are present laterally above pelvic-fin origin, between dorsal fins, caudal peduncle, and lower caudal lobe.

Comparison with other species. Morphometric data are presented in Table 1 . Cephaloscyllium pardelotum sp. nov. differs from C. circulopullum in lacking a dark lateral blotch between the pectoral and pelvic fins, and possessing a lobed anterior nasal flap. Cephaloscyllium pardelotum sp. nov. has a remarkably distinct color pattern from C. fasciatum . Although the two species have open dorsal saddles, C. pardelotum sp. nov. possesses saddle borders that are not dark and solid as in C. fasciatum . In contrast, the saddle borders of C. pardelotum sp. nov. are variegated and patchy and form an H-shape. Also, this new species has distinctive rosettes and no reticulated lines. The anal fin is slightly larger in the new species. Anal-fin posterior margin is 0.07 times in precaudal length for C. pardelotum sp. nov., but 0.03–0.04 times in precaudal length for C. fasciatum ( Fig. 2 ). Cephaloscyllium pardelotum sp. nov. differs from C. sarawakensis in color pattern, and size and position of the dorsal fins. The new species does not display the distinctive polka-dots of juvenile C. sarawakensis , nor the dark lateral blotch of C. sarawakensis . Overall, both dorsal fins of C. pardelotum sp. nov. are smaller than in other WNP species of swellshark. The first dorsal-fin base is relatively short in C. pardelotum sp. nov. ( Fig. 3 ). This length is 0.08 times in precaudal length in C. pardelotum sp. nov., whereas C. sarawakensis has a dorsal-fin base between 0.09–0.12 in precaudal length. The first dorsal-fin height is relatively short ( Fig. 4 ) in C. pardelotum sp. nov., at 0.05 in precaudal length. This measurement is 0.06–0.07 times in precaudal length in C. sarawakensis . In C. pardelotum sp. nov., the first dorsal fin originates behind the anterior half of the pelvic-fin base. In C. sarawakensis , however, the first dorsal fin originates closer to the pelvic-fin origin. Cephaloscyllium pardelotum sp. nov. can be separated from adult C. umbratile by overall color pattern, and morphology of the anterior nasal flap. Cephaloscyllium umbratile does not have open saddles, nor are they H-shaped.

Remarks. If young similar-sized specimens of C. pardelotum sp. nov., C. circulopullum , C. fasciatum , C. sarawakensis , and C. umbratile are examined side-by-side, it is fairly easy to tell that they are all separate species ( Fig. 5 ). Although the color pattern of adult C. pardelotum sp. nov. is presently unknown, its juvenile markings are quite distinct from any other Cephaloscyllium within this region.

Distribution. Cephaloscyllium pardelotum sp. nov. is known only from off the coast of southern Taiwan.

Etymology. The species is named after the Latin pardus for leopard, referring to the rosette-type spots along the dorsal and lateral surfaces.

Common name. Leopard-spotted swellshark.

Figures

FIGURE 1. Cephaloscyllium pardelotum sp. nov. holotype (CAS 224876); a. lateral view; b. dorsal view. Photos by D. A. Ebert

FIGURE 2. Scatter diagram of proportional dimensions of anal-fin posterior margin length for select Cephaloscyllium species.

FIGURE 3. Scatter diagram of proportional dimensions of first dorsal-fin height for select Cephaloscyllium species.

FIGURE 4. Scatter diagram of proportional dimensions of first dorsal-fin base length for select Cephaloscyllium species.

FIGURE 5. Lateral views of the WNP Cephaloscyllium, all about 220 mm TL; a. Cephaloscyllium pardelotum sp. nov.; b. Cephaloscyllium maculatum sp. nov.; c. Cephaloscyllium fasciatum; d. Cephaloscyllium umbratile; e. Cephaloscyllium sarawakensis; f. Cephaloscyllium circulopullum. Illustration by J. A. S. - Da Silva.