SPOTTED GULLY SHARK OR SHARPTOOTH HOUNDSHARK
Sweet William shark
The Spotted Gully shark or Sharptooth houndshark (Triakis megalopterus) is a species of shark in the family Triakidae. It is found inshore, in shallow waters on sandy or rocky bottoms and crevices from southern Angola to South Africa. This is a known active and schooling shark that remains close to the bottom. Some locals even call this shark Sweet William.
Family: Triakidae – Houndsharks
Common Name– Ground Sharks
Common Name– Houndsharks
Status: IUCN Red List NEAR THREATENED
Average Size and Length: They are born between 30-32 cm/11.8 inches-1 foot. Mature males have been measured between 130-140 cm/4-4.6 feet, and mature females between 140-150 cm/4-4.9 feet. The maximum is possibly over 170 cm/5.5 feet.
Average Weight: Some sharks have been recorded at 88 pounds.
Current Rare Mythical Sightings: Scottish zoologist Andrew Smith originally described the Sharptooth houndshark or Spotted Gully shark as a species of Mustelus in 1839, as part of his work Illustrations of the Zoology of South Africa. His description was based on two specimens caught off the Cape of Good Hope, South Africa. Smith named the shark megalopterus, from the Greek mega (“large”) and pteron (“wing”), referring to its large fins. Later authors have reassigned the Sharptooth houndshark to the genus Triakis. A 2006 phylogenetic study by J. Andrés López and colleagues, based on four protein-coding gene sequences, found that this species did not group with the Leopard shark (T. semifasciata). Instead, the Flapnose houndshark (Scylliogaleus quecketti) and it formed a clade within the Mustelus lineage. This result suggests that the two subgenera of Triakis—Cazon and Triakis—may not be closely related. A further study should be conducted (López, J.A.; Ryburn, J.A.; Fedrigo, O.; Naylor, G.J.P. (2006). “Phylogeny of sharks of the family Triakidae (Carcharhiniformes) and its implications for the evolution of carcharhiniform placental viviparity“. Molecular Phylogenetics and Evolution. 40 (1): 50–60).
Teeth and Jaw: The mouth is large with long furrows at the corners with the ones on the lower jaw almost meeting in the middle. The teeth are pointed and small they are also tightly packed to form pavement-like surfaces. Each tooth has a rounded, molar-like base that rises to a sharp, upright central cusp. Rarely, a pair of barely developed lateral cusplets could occur. Their teeth are a perfect combination of shark points for gripping active fish, and pavement like broad bases for crushing shells.
Head: The snout is short, broad and blunt. The nostrils are widely spaced and preceded by lobe-like flaps of skin that do not reach the mouth. The horizontally oval eyes have ridges underneath and have nictitating membranes.
Denticles: Often times the skin is loose.
Tail: The caudal peduncle is short and heavy without notches.
Demographic, Distribution, Habitat, Environment and Range: The Spotted Gully shark or the Sharptooth houndshark can be found in southern Angola to South Africa in the eastern Cape and on rare occasion to KwaZulu-Natal (30°S – 36°S). They can be found in shallow, inshore waters to the surf-line on sandy shores, rocks, crevices and in shallow bays. They don’t exceed 160 feet of depth and most are found around 33 feet deep. They are demersal subtropical.
Diet: They eat crabs (like the crab Plagusia chabrus), bony fish, cephalopods (specifically the Octopus vulgaris), and even small sharks and rays like catfish and guitarfish. Crustaceans include: crabs, slipper lobsters, and spiny lobsters. Bony fish include: morwongs, sea catfishes, drums, and porgies. Their diet evolves with age. Young sharks are known to almost exclusively eat crabs while older sharks eat a lot more bony fish. This shark has been observed deviating from its nocturnal habits to feed on Chokka squid (Loligo reynaudii) during their mass spawning (Sauer, W.H.H.; Smale, M.J. (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.).
The Broadnose Sevengill shark is known to prey on this shark.
Aesthetic Identification: The Spotted Gully shark or the Sharptooth houndshark is stout and robust, and typically a bronzy grey with many black spots and white ventrally. In young sharks, they may have very few spots, or no spots at all. There are also some adults that are plain without spots. The fins are broad, rounded and large. The interdorsal ridge is high. The dorsal fins have nearly vertical trailing margins, with the first originating over the pectoral fin rear tips. The second dorsal fin is about three-quarters as high as the first. The anal fin is much smaller than the second dorsal fin and originates well behind it. The pectoral fins in are broad and falcate in adults.
Biology and Reproduction: They are ovoviviparous without a yolk sac placenta. Mature females have a single functional ovary and two functional uteri. They have six to ten pups per litter. Litter size does increase with the size of the female. Pups within a single litter may vary in size by up to 30%. Pups are born between late May and August, on a 2- or 3-year cycle (some females can mate a few months after giving birth) after a gestation period of about 20 months. Females grow larger than males.
Males mature between 3.9/4.6 feet or 11–13 years of age, while females mature sexually between 4.3/4.9 feet or 15-16 years of age. The maximum lifespan is at least 25 years.
Behavioral Traits, Sensing and Intelligence: This shark is known to school. It schools in the summer, often with numerous pregnant females. Aggregations are well-documented in False Bay and may be related to reproduction, given the presence of many pregnant females. They actively patrol close to the bottom in captivity. Sometimes they patrol in midwater, but rarely in the open. It also may be more active at night. They have been observed pursuing prey almost onto the shore.
Speed: This is an active swimming shark.
Spotted Gully Shark or Sharptooth Houndshark Future and Conservation: They are currently near threatened because of its restricted range, low growth rate and low fertility. Locally this shark is common, but its range is a known heavily fished area. These sharks are also caught by sport anglers and commercial longline fisheries, but the commercial value is low. It is caught as bycatch by commercial fisheries targeting other species like the School shark, and it is often commonly mistaken for the Common smoothhound. This shark is strong in captivity and are highly adaptive and therefore are desired for public aquariums.
Spotted Gully Shark or Sharptooth Houndshark Recorded Attacks on Humans: Not a threat to humans.