TIGER CATSHARK

Taxonomy:

Phylum– Chordata

Class– Chondrichthyles

Order– Carcharhiniformes

Common Name– Ground Sharks

Family– Scyliorhinidae

Common Name– Catsharks

Genus– Halaelurus

Species– natalensis

Status: IUCN Red List DATA DEFICIENT

Average Size and Length: Each egg case measures 4×15 cm. Adolescent males have measured between 29-35 cm/11.4 inches-1.4 feet and adolescent females between 30-44 cm/11.8 inches-1.4 feet. Adult males have been measured between 35-45 cm/1.4 feet-1.5 feet. Adult females measure between 37-50 cm/1.2 feet-1.6 feet. The longest recorded is 50 cm/1.6 feet.

Current Rare Mythical Sightings: British ichthyologist Charles Tate Regan described the tiger catshark in a 1904 issue of the scientific journal Annals and Magazine of Natural History, based on two specimens presented to the British Museum by J. F. Queckett. He placed the species in the genus Scyllium (a synonym of Scyliorhinus) and gave it the specific epithet natalense, because the type specimens were reportedly collected off the Natal coast of South Africa, but there is much suspicion that they were mislabeled and actually came from Algoa Bay. Later authors reassigned this species to the genus Halaelurus. The Lined catshark (Halaelurus lineatus) was once treated as conspecific to the Tiger catshark, until it was described as a separate species in 1975.

Teeth and Jaw: The mouth is large, and forms a wide arch with short furrows around the corners. When the mouth is closed, the center of the lower jaw falls well short of the upper, leaving the upper teeth exposed. The teeth are small and 3-cusped (rarely 5-cusped), with the central cusp the longest. Male teeth have three cusps, with the center cusp much longer then the two surrounding cusplets. The center cusp is long and pointed.

Head: The head is broad. The snout tip is pointed and upturned. The large, horizontally oval eyes are raised above the head. The eyes are protected by nictitating membranes.  Beneath each eye is a broad ridge, and behind is a spiracle. The medium-sized nostrils are divided by lobe-like flaps of skin on their anterior rims. The nasal flaps do not reach the mouth. The gills are on the upper surface of the head above the mouth, and below and behind the eyes.

Denticles: The skin is thick; the dermal denticles have three-pointed crowns and are widely spaced compared to other species in the genus.

Tail: The short caudal fin has an indistinct lower lobe and a ventral notch near the tip of the upper lobe.

Demographic, Distribution, Habitat, Environment and Range: The Tiger catshark can be found in the southeast Atlantic and western Indian Ocean in South Africa (33°S – 35°S). The records in KwaZulu-Natal and Mozambique need confirmation, more than likely those are accounts of the Lined catshark. They can be found on or near the bottom on the continental shelf close inshore to 374 feet. Most records are less than 328 feet. One slope record states 1,165 feet, but that may be false; it is not confirmed. They prefer sandy flats and reef edges. They are considered subtropical demersal.

Diet: They eat small bony fish, fish offal, crustaceans, polychaetes, cephalopods, and small elasmobranchs.

The Tiger catshark has been observed at the spawning grounds of the chokka squid (Loligo vulgaris reynaudi), feeding on squid that have descended to the bottom to mate and deposit eggs. (Sauer, W. H. H.; Smale, M. J. (December 1991). “Predation patterns on the inshore spawning grounds of the squid Loligo vulgaris reynaudii (Cephalopoda: Loliginidae) off the south-eastern Cape, South Africa“. South African Journal of Marine Science. 11 (1): 513–523.)

Documented predators of this species include the Broadnose Sevengill shark (Notorynchus cepedianus) and the Sand Tiger shark (Carcharias taurus).

Aesthetic Identification: The Tiger catshark is yellow-brown above with ten pairs of broad dark brown bars enclosing lighter reddish areas. They do not have spots, and are cream colored ventrally. The body is slim and firm. The pectoral fins are fairly large and rounded. The origin of the first dorsal fin lies over the last third of the pelvic fin bases, while the origin of the much larger second dorsal fin lies over the rear of the anal fin. The claspers of adult males are moderately long and tapering, though those of some individuals may be knob-shaped and spiky. The anal fin is roughly equal in size to the pelvic fins, and smaller but longer-based than the second dorsal fin.

Biology and Reproduction: They are oviparous having 6-11 egg cases per oviduct; however, they typically have between 6-9. The egg cases are laid when the embryos are close to hatching, with the females attaching them to the bottom. The egg cases have thick tendrils at the corners that allow it to be secured to the sea floor. The eggs hatch within only one or two months of being laid, reducing the amount of time that they are exposed to predators.

Behavioral Traits, Sensing and Intelligence: They may segregate by size and by depth. They may also be less active or sluggish in nature.

Speed: A sluggish swimmer by nature.

Tiger Catshark Future and Conservation: There is not enough data to evaluate. Offshore trawlers may take adult Tiger catsharks. They are commonly caught as bycatch by prawn trawlers. Though edible, it is not a valued catch and is usually discarded.

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