December Elasmobranch of the Month: Winghead Shark
Author: Linda Weiss
The Winghead shark is a relatively small hammerhead species, with an average overall length of 1.86 m (6.1 ft). They get their name from their very wide, hammer-shaped head, which can be as wide as half of their body length. They have a slender body shape. Their coloration is brown to gray on top and cream-colored underneath. Like its cephalofoil (head), its first dorsal fin is tall relative to the shark’s body length. Contrarily, this species’ pectoral fins are relatively short. The caudal fin is forked with the upper lobe significantly larger than the lower lobe. The Winghead shark’s mouth is small. The upper jaw holds 15 – 16 rows of teeth, while the lower jaw has 14 rows. Their teeth are small, narrow triangular in shape, with smooth edges.
Habitat and Distribution
This shark species can be found in the Indo-West Pacific from the Arabian/Persian Gulf through to south Asia, northern Australia and Papua New Guinea. In this range they prefer tropical water on continental and island shelves nearer to shore, at depths of 0 – 40 m (0-131 ft).
The Winghead’s diet includes small fish, shrimp, crabs, and cephalopods.
This shark species mates once a year. Their gestation is estimated to be 8- 11 months with reproduction occurring viviparously. This form of reproduction involves the young developing inside the female, receiving nourishment through a placental sac before being birthed alive. Litter sizes range typically between 5-25 pups, that are 32 - 45 cm (12.6 - 17.7 inches) long. Males become sexually mature around 7 years of age and females at around 9 years of age.
The IUCN Red List of Threatened Species currently lists the Winghead shark as Endangered, with a decreasing population trend.
Winghead sharks are overfished for their fins and meat, which are traded locally, nationally, and internationally. Like many shark species their fins are taken for use in making shark fin soup.
EDGE of Existence
Fishes of Australia
Bray, D.J. 2019, Eusphyra blochii in Fishes of Australia, accessed 08 Dec 2021, https://fishesofaustralia.net.au/home/species/3143
Planet Shark Divers
The IUCN Red List of Threatened Species
Smart, J.J. & Simpfendorfer, C. 2016. Eusphyra blochii. The IUCN Red List of Threatened Species 2016: e.T41810A68623209. https://dx.doi.org/10.2305/IUCN.UK.2016-1.RLTS.T41810A68623209.en. Downloaded on 08 December 2021.