LEOPARD CATSHARK

Taxonomy:

Phylum– Chordata

Class– Chondrichthyles

Order– Carcharhiniformes

Common Name– Ground Sharks

Family– Scyliorhinidae

Common Name– Catsharks

Genus– Poroderma

Species– pantherinum

Status: IUCN Red List DATA DEFICIENT

Average Size and Length: Mature males have been measured between 54-58 cm/1.8-1.9 feet. Mature females have been measured between 58-61 cm/1.9-2 feet. The maximum recorded is 74 cm/2.4 feet. There are now some reports of them growing as long as 84 cm/2.8 feet.

Average Weight: 7.1 pounds, with the males growing slightly larger than the females.

Current Rare Mythical Sightings: In an 1837 issue of Proceedings of the Zoological Society of London, Scottish physician and zoologist Andrew Smith listed without descriptions the new genus Poroderma, containing the species P. africanum (the Pyjama shark), P. pantherinum, P. submaculatum, and P. variegatum. German biologists Johannes Peter Müller and Friedrich Gustav Jakob Henle assigned these sharks to the genus Scyllium, and in their 1838–1841 Systematische Beschreibung der Plagiostomen offered descriptions for S. pantherinum and S. variegatum, and listed two more names without description, S. leopardinum and S. maeandrinum. In 1934, American zoologist Henry Weed Fowler described P. marleyi, characterized by large black spots. Resolving the identity of P. marleyi proved especially problematic and it was not confirmed to be a synonym of this species until 2003. The valid scientific name of the Leopard catshark is considered to be Poroderma pantherinum, attributed to Müller and Henle as they were responsible for the description.

Teeth and Jaw: The mouth is wide and arched, with short furrows at the corners extending onto both jaws. The upper teeth are exposed when the mouth is closed. There are 18–30 and 13–26 tooth rows on either side of the upper and lower jaws. Both male and female Leopard catsharks have teeth with a long, pointed central cusp and two very small surrounding cusplets on either side. However, the teeth of males and females do differ slightly, for males have a slight curve to their long central cusp.

Head: The head and snout are short and slightly flattened. The snout tip is slightly pointed. Each nostril is split into tiny incurrent and excurrent openings by a three-lobed flap of skin in front, of which the central lobe forms a slender barbel. The nasal barbels reach the mouth, which extends behind the front of the eyes. The horizontally oval eyes are equipped with nictitating membranes and placed high on the head, with a thick ridge running under each.

Denticles: The very thick skin is covered by well-calcified dermal denticles. Each denticle has an arrowhead-shaped crown with three posterior points, mounted on a short stalk.

Tail: The caudal fin is short and broad, with an indistinct lower lobe and a ventral notch near the tip of the upper lobe. It is asymmetrical in shape.

Demographic, Distribution, Habitat, Environment and Range: The Leopard catshark can be found in the southeast Atlantic and western Indian Ocean (28°S – 36°S) in sub-tropical climates. They are apparently endemic to South Africa in both Capes and rarely seen in KwaZulu-Natal. There are some records from Mauritius and Madagascar, but those require verification. They can be found over the continental shelf to the upper slope from the surf zone and the intertidal zone to 840 feet, but are abundant at around 66 feet deep. They are found on or near the bottom. They seem to favor rocky reefs, kelp beds, and sandy flats. Given the color pattern diversity within the species, its range is likely fragmented into a number of small local populations along the South African coast.

Diet: They feed on small bony fish and invertebrates. Like its relative has been observed attacking octopus and cuttlefish by seizing and tearing off tentacles with a twisting motion. It will also temporarily abandon its nocturnal habits to take advantage of the daytime mass spawning of the chokka squid. It will lie motionless amongst the squids’ egg masses with their heads hidden, and make sudden lunges at female squid that have descended to the sea floor to attach their eggs.

Predators of the leopard catshark include larger sharks and marine mammals. Its eggs are also heavily preyed upon.

Aesthetic Identification: The Leopard catshark has striking leopard-like badges of dark spots and lines surrounding light centers. They are usually arranged in irregular longitudinal rows, with variations including numerous small dense spots to very large dark spots and partial longitudinal stripes. The color pattern is variable, with individuals ranging from almost white to a glossy jet black and covered by diverse patterns of black spots, blotches, rosettes, and/or lines. The color pattern changes with age and some forms seem to be location-specific, suggesting the presence of multiple distinct, local populations. In the past, some of the more distinct color forms have been described as different species. There are four named forms: ‘typical’, with leopard-like rosettes and broken lines, ‘marleyi’, with large round spots, ‘salt and pepper’, with densely packed dots, and ‘melanistic’, with an almost completely black upper surface and irregular stripes and/or spots; many sharks are intermediate between these forms. Color pattern is affected by development: all hatchling sharks have large black spots, that with age tend to break up into rosettes and smaller spots, that may eventually merge into lines. The ‘marleyi’ form appears to be a type of paedomorphosis, in which in the hatchling pattern is carried into adulthood. Color pattern is also related to geographic location, with the ‘marleyi’ and ‘salt and pepper’ forms apparently restricted to the waters off the Eastern Cape and KwaZulu-Natal.

The body is stout, laterally compressed and tapers down to the tail. The dorsal fins are set far back. The first dorsal fin is much larger than the second dorsal fin. The first dorsal fin originates over the rear of the pelvic fins. The second originates over the midpoint of the anal fin base. The bases of the pectoral and pelvic fins are about equal. The pectoral fins are large and broad while the pelvic fins are much lower. Adult males have stubby claspers with the inner margins of the pelvic fins partially fused over them to form an apron.

Biology and Reproduction: They are oviparous with one egg per oviduct. Reproduction is reported as year-round. Each egg case is rectangular in shape with long tendrils, light colored, and is 7 cm/2.8 inches long and 3 cm/1.2 inches across. Females attach them to structures on the sea floor. Reproduction in aquaria may be similar to that of the Pyjama shark.

The average lifespan is reported to be around 10 years with some reports between 15 and 19 years.

The Leopard catshark is known to be parasitized by the praniza larvae of the isopod Gnathia pantherina, which infest the nostrils, mouth, and gills.

Behavioral Traits, Sensing and Intelligence: They are apparently nocturnal and hunt after dark. In daytime, they rest inside caves and crevices, sometimes in groups.

When threatened, it curls into a ring with its tail covering its head.

Speed: More than likely slow swimming.

Leopard Catshark Future and Conservation: There is not enough data to evaluate. They are taken by trawlers and anglers. Small and harmless, the Leopard catshark adapts well to captivity and is often exhibited in public aquariums. It is popular because of its small size and attractive appearance. It is caught by commercial and recreational fishers as bycatch, and often killed as a pest.

The possible distribution of this shark across many small, distinct populations give rise to further investigation. Its inshore habitat is heavily fished and impacted by human activity, so it should be further watched and assessed.

Leopard Catshark Recorded Attacks on Humans: Not a threat to humans.