Spotted Gully Shark: Triakis megalopterus

Family: Triakidae
Common name(s)

Spotted Gully Shark, Sharptooth Houndshark.

Identification

Body slender. Snout fairly short and somewhat pointed. Upper labial furrows the same length or slightly longer than lower. Small, visible spiracle behind eye. First dorsal fin origin over pectoral fin free rear tip. Second dorsal fin larger than anal fin. Second dorsal origin slightly posterior to pelvic fin free rear tip. Lower caudal lobe indistinct but with a rounded apex. Dorsal coloration brown or bronzy with irregular scattered black spots. Spots may be absent in juveniles and in some adults.

Size

Maximum length 208cm. Size at birth 40-45cm.

Habitat

A temperate inshore species that inhabits sandy bays, rocky reefs, and kelp forests. usually found within the first 10m but recorded to more than 50m.

Distribution

Spotted gully sharks have a limited range in southern Africa, from Angola in the Atlantic, to KwaZulu-Natal in the Indian Ocean.

Conservation Status

LEAST CONCERN

The Spotted Gully Shark (Triakis megalopterus) has a late age-at-maturity and a long gestation period that lead to low productivity and vulnerability to overfishing. It is caught extensively in recreational line fisheries and occasionally as a minor bycatch species in beach seine, longline, and trawl fisheries. Recreational fishers typically release this species. Catches of the Spotted Gully Shark in the commercial and recreational line fisheries in False Bay, South Africa peaked in 1990 and declined thereafter. Trend analysis of 21 years of catch-per-unit-effort data from 1996–2017 from the De Hoop Marine Protected Area (MPA), South Africa indicate an increase in population over the past three generation lengths (60 years). Commercial fishing for Spotted Gully Shark is prohibited in South Africa with minimal bycatch of this species and recreational fishing permitted but regulated. Hence, this data from the MPA may approximate the trends of the species in the region. There are currently no data available from other areas, but given an estimated increase in South Africa over the past three generations (60 years), the typical release of this species by recreational fishers, likely low post-release mortality, and mostly low fishing pressure elsewhere, it is suspected that the population trend is stable over the past three generation lengths (60 years) and is not suspected to be close to reaching the population decline threshold. Therefore, the Spotted Gully Shark is assessed as Least Concern.

Citations and References
Pollom, R., Da Silva, C., Gledhill, K., McCord, M.E. & Winker, H. 2020. Triakis megalopterusThe IUCN Red List of Threatened Species 2020: e.T39362A124406649. https://dx.doi.org/10.2305/IUCN.UK.2020-2.RLTS.T39362A124406649.en. Downloaded on 09 November 2020.

Reproduction

An aplacental viviparous species (without a yolk-sac placenta). 5-15 pups per litter.

Diet

Predates mainly on small bony fishes, small sharks, and crustaceans. Younger animals target crustaceans more heavily.

Behavior

Banded houndsharks hide within caves and in deep crevices during the day. Known to school in the summer.

Reaction to divers

Usually very shy, retreating deeper into crevices when disturbed. Will not approach divers in baited situations.

Diving logistics

Miller’s Point near Simonstown (and numerous other spots in False Bay where there is suitable cover), are excellent places to look for spotted gully sharks.
We (Big Fish Expeditions) usually see a few houndsharks in False Bay during our South African Shark Safaris but they are much shyer than the catsharks and sevengill sharks that nonchalantly swim around the reef. Gully sharks can generally be found by looking into caves and swim-throughs. However they usually flee immediately when approached, so the best way to get a close look at them, is to work in buddy pairs, i.e. one diver swims into one end of the swim-through while the other diver waits outside the far end and enjoys/photographs the shark(s) as they exit.

Similar species

Smoothhound Sharks Five species of similarly shaped smoothhounds are present within range of the spotted gully shark. None display black spots.