A revision of the western North Pacific swellsharks, genus Cephaloscyllium Gill 1862 (Chondrichthyes: Carcharhiniformes: Scyliorhinidae), including descriptions of two new species
Author
Schaaf-Da, Jayna A.
Author
Ebert, David A.
text
Zootaxa
2008
1872
1
28
journal article
10.5281/zenodo.183986
4ced8216-c041-4541-81aa-55e2f672a565
1175-5326
183986
Cephaloscyllium maculatum
sp. nov.
(
Figs. 6
,
5
b, 7b, 10b;
Table 1
)
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 |
TRW 12.4 |
13.3 |
D2L 6.9 |
6.9 |
GIR 35.6 |
47.9 |
D2A 5.9 |
5.6 |
CPH 3.2 |
3.7 |
D2B 5.0 |
4.3 |
CPW 2.2 |
3.2 |
D2H 2.5 |
2.1 |
HDL 19.8 |
22.3 |
D2I 2.2 |
2.7 |
PG1 15.3 |
16.0 |
D2P 2.0 |
2.7 |
PSP 9.9 |
9.6 |
ANL 10.4 |
10.1 |
POB 5.9 |
6.4 |
ANA 6.9 |
7.4 |
EYL 3.7 |
3.2 |
ANB 7.4 |
8.0 |
SPL 1.0 |
0.5 |
ANH 3.5 |
3.2 |
ESL 1.0 |
1.1 |
ANI 3.0 |
1.6 |
ING 4.5 |
4.8 |
ANP 5.0 |
3.7 |
GS1 1.7 |
1.6 |
CDM 26.7 |
25.5 |
GS2 1.7 |
1.6 |
CFW 6.4 |
6.4 |
GS3 1.7 |
1.6 |
CPV 9.4 |
10.1 |
GS4 1.5 |
1.6 |
CST 4.5 |
4.3 |
GS5 1.5 |
1.1 |
CTR 5.4 |
5.3 |
POR 5.0 |
4.3 |
CTL 6.9 |
6.4 |
PRN 2.5 |
1.6 |
PDO 11.9 |
18.1 |
MOL 4.2 |
3.7 |
DAO 3.5 |
4.3 |
MOW 10.4 |
7.4 |
DAI 0.0 |
0.0 |
NOW 3.0 |
2.7 |
U tot 60 |
48 |
INW 2.5 |
4.0 |
L tot 60 |
52 |
ANF 1.2 |
1.6 |
VERT 120 |
117 |
P1L 13.4 |
11.7 |
mono 44 |
46 |
P1A 12.4 |
11.7 |
predip 30 |
33 |
P1B 8.9 |
8.0 |
caudaldip 46 |
38 |
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.
FIGURE 6.
Cephaloscyllium maculatum
sp. nov.
holotype (CAS 224877); a. lateral view; b. dorsal view. Photos by D.A. Ebert.
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.
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 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.
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.
FIGURE 8.
Scatter diagram of proportional dimensions of internarial width for selected
Cephaloscyllium
species.
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.