Cephaloscyllium maculatum, 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 : 7-12

Cephaloscyllium maculatum sp. nov.

( Figs. 6 , 5 b, 7b, 10b; Table 1 )

Type Series and Locality. Holotype, CAS 224877, immature male, 188 mm TL, collected from Su-ao, Taiwan, 24°35.7'N, 121°50.7'E, collected by David A. Ebert on 3 April 1988, in excellent condition.

Diagnosis. Body comparatively slender, head short; pre-first dorsal length 48.9% TL. Mouth wide, its width 0.33 in head length. Snout very short, moderately flattened, broadly rounded; anterior nasal flaps short and triangular, not overlapping mouth posteriorly; large internarial distance. First dorsal fin small; only slightly larger than second dorsal fin; first dorsal-fin origin opposite pelvic-fin insertion. Pectoral and anal fins relatively large and broad. Color pattern consists of eight angular dorsal saddles; including four pre-first dorsal fin saddles; angular, open, and dark-outlined lateral blotch present between the paired fins.

Description. Proportional dimensions in percentage of TL are shown in Table 1 . Head short, its length 0.29 times precaudal length, pre-pectoral length 19.7% TL. Snout moderately flattened, broadly rounded, and short; preorbital length 0.29 times head length; 0.80 in interorbital width. Eye small, its horizontal eye length 0.14 times head length; cat-like. Spiracle small, its diameter 0.16 times horizontal eye length. Gill openings very small, vertical length of first gill opening 0.07 in head length. Mouth relatively small, its width 0.33 in head length; labial furrows absent. Nostrils large; internarial distance 0.54 times mouth width; anterior nasal flaps short and triangular, not overlapping mouth posteriorly. First dorsal-fin small; first dorsal-fin height 0.41 in length; origin about opposite or behind half of pelvic-fin base, pre-first dorsal length 48.9% TL. Second dorsal fin small; only slightly smaller than first; second dorsal-fin height 0.30 in length; pre-second dorsal length 0.82 times precaudal length; second dorsal-fin height 0.57 in first dorsal-fin height. Pectoral fins relatively large and broad; anterior margin 0.52 times head length; base 0.68 times in anterior margin. Pelvic fin small; its length 0.10 in precaudal length; base 0.80 in length. Anal fin relatively large; its height 0.04 and its length 0.13 times precaudal length; larger than either dorsal fin; second dorsal-fin height 0.66 in anal-fin height; first dorsal-fin height about equal to anal-fin height. Caudal fin broad, asymmetrical, with subterminal notch; dorsal-lobe length 0.32 times precaudal length; ventral-lobe length 0.40 times 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 immature males. Total vertebrae 117, monospondylous 46, precaudal 79, and pre-caudal diplospondylous 33.

Size and sexual maturity. Unknown at present.

Coloration. Background color medium brown to beige dorsally, pale ventrally; without polka-dots, rosettes, random speckles, or light-colored spots; spots on snout absent; open, dark lateral blotch present between paired fins. Eight open dorsal saddles clearly defined; first behind orbitals, second in line with the gills, third behind pectoral-fin insertion, fourth just before pelvic-fin origin, then one at each dorsal-fin base, one at caudal-fin origin, and dorsal-caudal lobe; saddles open, outline dark brown and solid. Angular open blotches present laterally above pectoral fins between second and third dorsal saddles, and spanning gill series; each paired fin has one angular blotch placed dorsally, larger blotches on larger fins.

Comparison with other species. Morphometric data are presented in Table 1 . Cephaloscyllium maculatum sp. nov. differs from C. pardelotum sp. nov. in lacking a lobate anterior nasal flap, and possessing a color pattern of dark outlined dorsal saddles. Cephaloscyllium maculatum sp. nov. has open saddles, but the borders are dark and solid and not H-shaped. Cephaloscyllium maculatum sp. nov. is separate from C. circulopullum in lacking a closed circular lateral blotch between the pectoral and pelvic fins, and having a greater internarial distance, and smaller mouth width. Cephaloscyllium maculatum sp. nov. differs from C. fasciatum in lacking a lobate anterior nasal flap ( Fig. 7 ), having a less-variegated color pattern, and a smaller mouth width. Furthermore, the mouth length is shorter in the new species than C. fasciatum ; 3.7% TL and 5.1–6.2% TL respectively. In addition, the internarial width is greater in C. maculatum sp. nov., at 4.0% TL, compared to C. fasciatum at 2.0–3.2% TL. Cephaloscyllium maculatum sp. nov. is separate from C. sarawakensis in lacking a vertically elongated closed lateral blotch between the paired fins, and having a greater internarial distance. The internarial space of C. maculatum sp. nov. is 4.0% TL; in C. sarawakensis , this measurement is 1.9–2.8% TL ( Fig. 8 ). The mouth width is smaller in the new species, at 7.4% TL, whereas this measurement is consistently greater than 8.0% TL C. sarawakensis ( Fig. 9 ). Cephaloscyllium maculatum sp. nov. differs from adult C. umbratile in lacking light colored spots. Cephaloscyllium umbratile does not have open saddles, as observed in the new species.

Remarks Figure 10 shows similarly-sized specimens of C. maculatum sp. nov., C. sarawakensis , and C. umbratile in dorsal view. In this figure, it is fairly easy to conclude that these three specimens represent distinct species of Cephaloscyllium . Although the color pattern of adult C. maculatum sp. nov. is unknown at present, the juvenile markings are unique.

Distribution. Cephaloscyllium maculatum sp. nov. is only known from off the east coast of Taiwan. Etymology. The species is named after the Latin maculata for spotted, referring to the lateral spots. Common name. Spotted swellshark.

Figures

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.

FIGURE 6. Cephaloscyllium maculatum sp. nov. holotype (CAS 224877); a. lateral view; b. dorsal view. Photos by D. A. Ebert.

FIGURE 7. Anterior nasal flaps 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.

FIGURE 8. Scatter diagram of proportional dimensions of internarial width for selected Cephaloscyllium species.

FIGURE 9. Scatter diagram of proportional dimensions of mouth width for select Cephaloscyllium species.

FIGURE 10. Dorsal view of select juvenile Cephaloscyllium; all about 200 mm TL; a. Cephaloscyllium sarawakensis (CAS 224882); b. Cephaloscyllium maculatum sp. nov. (CAS 224877); c. Cephaloscyllium umbratile (CAS 224880). Photo by D. A. Ebert.

Tables

TABLE 1. Morphometric and meristic data for the holotype (HT) specimens for Cephaloscyllium pardelotum sp. nov. (CAS 224876) and Cephaloscyllium maculatum sp. nov. (CAS 224877). TL is the actual measurement in millimeters; all other measurements are expressed as percentage of TL. VERT—total vertebral count, mono—monospondylous centra count, predip—precaudal diplospondylous centra count, caudaldip—caudal diplospondylous centra count, U tot—tooth count of upper jaw, L tot—tooth count of lower jaw. Abbreviations are listed in Appendix 1.

	C. pardelotum sp. nov	C. maculatum sp. nov.		C. pardelotum sp. nov	C. maculatum sp. nov.
	HT	HT		HT	HT
Measurement	CAS 224876	CAS 224877	Measurement	CAS 224876	CAS 224877
TL	202	188	P1H	8.9	7.4
PCL	72.3	77.7	P1I	5.4	3.7
PD2	60.4	63.8	P1P	8.4	6.9
PD1	48.0	48.9	D1L	8.7	9.0
IDS	6.9	9.0	D1A	7.9	8.0
DCS	6.4	7.4	D1B	5.9	6.9
PAL	57.4	60.1	D1H	3.4	3.7
PP2	41.1	43.1	D1I	3.0	2.7
PP1	18.3	19.7	D1P	3.0	3.7
SVL	45.0	46.8	P2L	10.4	8.0
PPS	14.9	18.6	P2A	5.4	5.3
PAS	8.4	11.2	P2B	6.9	6.4
PCA	22.3	22.9	P2H	3.5	3.7
ACS	5.9	6.4	P2I	3.0	2.7
INO	8.2	8.0	P2P	6.9	5.3
HDH	7.4	10.1	CLO	--	1.1
HDW	13.9	13.3	CLI	--	3.7
TRH	8.4	12.8	CLB	--	0.5