Chiloscyllium punctatum Müller et Henle, 1838

Chiloscyllium punctatum Müller et Henle, 1838

IUCN standard name :: Grey Carpetshark Fig. 5 View Figure 5 , Table 1 View Table 1

Material examined.

UPVMI 3124, 302 mm TL, male, fish landing site, Roxas City, Capiz Province, Philippines, trawl, November 2021, coll. M. Batay. UPVMI 3125, 536 mm TL female, same data as preceding. UPVMI 3122, 553 mm TL, male, fish market, Tangalan, Aklan Province, Philippines, 23 November 2020, coll. M. Macavinta.

Morphological description.

(based on UPVMI 3124): Body small and slender without lateral dermal ridges. Eyes relatively small and oval, without nictitating eyelids; spiracles moderately small, located below eyes. Snout rounded and broad. Mouth small, located closer to eyes than snout tip. Nostrils small and subterminal, partially covered by nasal flap; nasal flap broad just reaching mouth; sensory barbels on each nostril very short. Teeth on both jaws small with single small cusp. Dorsal fins fully erect, equal in size; first dorsal fin originating behind pelvic-fin origin; posterior margin concave. Anal fin moderately long, originating behind free rear tip of second dorsal fin; anal-fin base length shorter than base of lower caudal-fin lobe (9 % vs. 16 % of TL, respectively). Pectoral fin angular with rounded free rear tips, originating just below third gill opening. Pelvic fin slightly smaller than dorsal fins, located just behind pectoral fin. Caudal fin asymmetrical; subterminal notch well developed; ventral lobe absent; precaudal pits absent. Gill slits on both sides five, small; fourth and fifth gill slits situated extremely closed to one another, making fifth gill slit hardly noticeable.

Color of fresh specimens. UPVMI 3124 (smallest specimen): Body and head white with brown to black transverse bands, underside white; bands extending to anal, dorsal, and pectoral fins; pelvic fin white. UPVMI 3125 (medium sized): Body, head and fins brown with faint brown bands. UPVMI 3122 (largest specimen): Body, head, and fins uniformly brown, colored bands absent.

Color of preserved specimen. UPVMI 3124 and UPVMI 3125: Transverse dark brown bands still visible on the body, head, and fins; underside white.

Distribution.

Indo – Pacific. western Indian Ocean: Arabian Sea and southern India; western Pacific: Thailand, Indonesia, Philippines, Japan, New Guinea, and Australia ( Human 2022).

DNA barcode.

COI sequences of 617 bp were submitted to GenBank with the following accession numbers: OR 614477 ( UPVMI 3124), OR 614474 ( UPVMI 3125), and OR 614472 ( UPVMI 3122).

Conservation status.

Near Threatened

Remarks.

Chiloscyllium punctatum can reach a maximum total length of 1050 mm and has been found in the intertidal zone at depths exceeding 85 m ( Compagno 2001). There have been reports of occurrences in Philippine waters, specifically in Cebu (Cebu City, and Lapulapu), Kalinga (Pasil), Mindoro Island, Negros Oriental (Dumaguete), Palawan, and Zamboanga ( Compagno et al. 2005; Gonzales 2013; Aquino et al. 2023).

The specimen was identified as C. punctatum based on several combined characteristics, including a slender body and tail, absence of lateral dermal ridges on the body, a concave posterior margin of dorsal fins, and an anal-fin base shorter than the base length of the lower caudal-fin lobe (9 % of TL vs. 16 % of TL, respectively). As mentioned in the remarks under C. plagiosum , C. punctatum is often confused with this species, as well as with C. griseum and C. hasselti . In addition to the previous points of comparison, C. punctatum can be distinguished from C. griseum and C. hasselti by the relative size of its dorsal fins, which are larger than the pelvic fins in C. punctatum , but smaller in the other two species ( Compagno and Niem 1998 a). The three specimens collected in this study consistently have first dorsal-fin heights (12 % or 16 % of TL, mean 13 % TL) and second dorsal-fin heights (11 % or 15 % TL, mean 12 % TL) larger than the pelvic-fin height (10 % TL). Additionally, the base lengths of the first (8 % or 12 % TL, mean 9 % TL) and second dorsal fins (9–12 % TL, mean 10 % TL) exceeded the pelvic-fin base (6 % or 7 % TL, mean 7 % TL) (see Table 1 View Table 1 ). The identification of these three specimens was further confirmed using COI data, which showed them forming a distinct clade with the sequence of C. punctatum , separate from those of closely related species (Fig. 3 View Figure 3 ).