Appearance
The puffadder shyshark is more slender than other shysharks, with a short, broad, dorsally flattened head and a narrowly rounded snout. The large, oval-shaped eyes have cat-like slit pupils, a simple nictitating membrane , and a prominent ridge underneath. The nostrils are very large, with a pair of greatly expanded, triangular flaps of skin in front that are fused together and reach the mouth. There is a deep groove connecting the excurrent opening of each nostril to the mouth, obscured by the nasal flaps. The mouth is short with furrows at the corners on both jaws. There are 26–30 tooth rows in the upper jaw and 27–33 tooth rows in the lower jaw. Tooth shape is sexually dimorphic: those of males are longer and three-pointed, while those of females are shorter and five-pointed. Unusually, the two halves of the lower jaw are connected by a special cartilage, which allows a more even distribution of teeth and may increase bite strength.The five pairs of gill slits are positioned somewhat on the upper surface of the body. The dorsal, pelvic, and anal fins are all of similar size. The dorsal fins are located far back on the body, the first originating behind the pelvic fin origins and the second behind the anal fin origin. The pectoral fins are broad and of moderate size. The short, broad caudal fin comprises about one-fifth of the body length and has a deep ventral notch near the tip of the upper lobe and a barely developed lower lobe. The skin is thick and covered by well-calcified, leaf-shaped dermal denticles. The dorsal coloration consists of a light to dark brown background with a series of 8–10 striking yellowish to reddish brown "saddles" with darker margins, all covered by a profusion of small white spots. The underside is white. This species attains a length of 60 cm , with a maximum record of 69 cm . Sharks found west of Cape Agulhas are smaller than those found east, reaching only 48 cm long.
Distribution
The range of the puffadder shyshark is limited to the continental shelf along the coast of South Africa, from Langebaan Lagoon in Western Cape Province to the western shore of Algoa Bay. Previous records of it being found as far north as Durban are now thought to be misidentifications of other species. This bottom-dwelling shark is most common over sandy or rocky bottoms. It is found in progressively deeper water towards the northeastern portion of its range, from 0–15 m off Cape Town to 40–130 m off KwaZulu-Natal; this distribution pattern may reflect this shark's preference for cooler waters.Behavior
Quite common within its small range, the sluggish and reclusive puffadder shyshark is often seen lying still on the sea floor. It is gregarious and several individuals may rest together. A generalist predator with grasping dentition, the puffadder shyshark is known to take a variety of small benthic prey: crustaceans , annelid worms , bony fishes , cephalopods , and fish offal. Overall, the most important component of this shark's diet is crustaceans, followed by polychaetes and then fishes. Males seem to prefer polychaetes, while females prefer crustaceans. It has been observed attacking a common octopus by tearing off an arm with a twisting motion.The puffadder shyshark is preyed upon by larger fishes, such as the broadnose sevengill shark . The Cape fur seal has been documented capturing and playing with puffadder shysharks, tossing them into the air or gnawing on them. The shark is often injured or killed during these encounters; the seal may eat torn-off pieces of flesh, but seldom consumes the entire shark. On occasion, black-backed kelp gulls take advantage of this behavior and steal the sharks from the seals. When threatened or disturbed, the puffadder shyshark adopts a characteristic posture in which it curls into a ring and covers its eyes with its tail; this reaction is the basis for the common names "shyshark" and "doughnut", and is likely meant to make the shark harder for a predator to swallow.
The eggs of the puffadder shyshark are fed upon by the whelks ''Burnupena papyracea'' and ''B. lagenaria'', at least in captivity. Known parasites of this species include the trypanosome ''Trypanosoma haploblephari'', which infests the blood, the nematode ''Proleptus obtusus'', which infests the intestine, and the copepods ''Charopinus dalmanni'' and ''Perissopus oblongatus'', which infest the skin. Another parasite is the praniza larval stage of the isopod ''Gnathia pantherina'', which infests the nares, mouth, and gills. The deep-penetrating mouthparts of these larvae significantly damage local tissue, causing bleeding and inflammation.
Habitat
The range of the puffadder shyshark is limited to the continental shelf along the coast of South Africa, from Langebaan Lagoon in Western Cape Province to the western shore of Algoa Bay. Previous records of it being found as far north as Durban are now thought to be misidentifications of other species. This bottom-dwelling shark is most common over sandy or rocky bottoms. It is found in progressively deeper water towards the northeastern portion of its range, from 0–15 m off Cape Town to 40–130 m off KwaZulu-Natal; this distribution pattern may reflect this shark's preference for cooler waters.Quite common within its small range, the sluggish and reclusive puffadder shyshark is often seen lying still on the sea floor. It is gregarious and several individuals may rest together. A generalist predator with grasping dentition, the puffadder shyshark is known to take a variety of small benthic prey: crustaceans , annelid worms , bony fishes , cephalopods , and fish offal. Overall, the most important component of this shark's diet is crustaceans, followed by polychaetes and then fishes. Males seem to prefer polychaetes, while females prefer crustaceans. It has been observed attacking a common octopus by tearing off an arm with a twisting motion.The puffadder shyshark is preyed upon by larger fishes, such as the broadnose sevengill shark . The Cape fur seal has been documented capturing and playing with puffadder shysharks, tossing them into the air or gnawing on them. The shark is often injured or killed during these encounters; the seal may eat torn-off pieces of flesh, but seldom consumes the entire shark. On occasion, black-backed kelp gulls take advantage of this behavior and steal the sharks from the seals. When threatened or disturbed, the puffadder shyshark adopts a characteristic posture in which it curls into a ring and covers its eyes with its tail; this reaction is the basis for the common names "shyshark" and "doughnut", and is likely meant to make the shark harder for a predator to swallow.
The eggs of the puffadder shyshark are fed upon by the whelks ''Burnupena papyracea'' and ''B. lagenaria'', at least in captivity. Known parasites of this species include the trypanosome ''Trypanosoma haploblephari'', which infests the blood, the nematode ''Proleptus obtusus'', which infests the intestine, and the copepods ''Charopinus dalmanni'' and ''Perissopus oblongatus'', which infest the skin. Another parasite is the praniza larval stage of the isopod ''Gnathia pantherina'', which infests the nares, mouth, and gills. The deep-penetrating mouthparts of these larvae significantly damage local tissue, causing bleeding and inflammation.
Evolution
The puffadder shyshark is oviparous; there is no distinct breeding season and reproduction occurs year-round. Females deposit egg capsules one or two at a time, attaching them to vertical structures such as sea fans. The thin-walled egg cases are brown with distinctive pale transverse bands; and have a slightly furry texture and long adhesive tendrils at the corners. They are smaller than those of other shyshark species, measuring 3.5–5 cm long and 1.5–3 cm across. The young shark hatches after three months, and measures around 9 cm long. The length at maturation for both sexes has been reported as anywhere from 35 to 55 cm by various sources; this high degree of variation may reflect regional differences as sharks from deeper waters in the eastern part of its range seem to mature at a larger size than those from the west. The age at maturation is estimated to be around 7 years, and the maximum lifespan is at least 22 years.References:
Some text fragments are auto parsed from Wikipedia.
