Pelagic thresherPTH

Alopias pelagicus

Alo.pel secondary
Alpopias pelagicus upper lower teeth

Characteristic features:

  • Upper caudal lobe nearly as long as rest of shark
  • Profile of head strongly arched between eyes
  • No deep grooves on head
  • Eyes moderately large, almost central on side of head
  • First dorsal-fin origin closer to pectoral-fin rear tip than pelvic-fin base
  • White part of belly not extending over pectoral-fin base

Colour:

Dorsal surfaces greyish to bluish grey, often with a metallic hue. Ventral surfaces white.

Size:

Up to at least 390 cm TL; birth size 130–160 cm TL.

Distribution:

Tropical and subtropical waters of the Indo-Pacific, from the surface to at least 152 meters depth.
View FAO distribution map

Habitat:

A pelagic and mostly oceanic species that occasionally enters shallower waters near outer reef edges or seamounts.

Biology:

Feeds on squid and small pelagic fishes, using its long whip-like upper caudal lobe to strike and stun its schooling prey. Length at maturity is 256–290 cm TL and 260–270 cm TL for females and males respectively. Age at maturity is 8–9 years and 7–8 years for females and males respectively. Reproductive mode is viviparous with oophagy with no reproductive seasonality. Litter size is 2 pups, 1 per uterus.

Indonesian fisheries:

A very common catch in the tuna and shark longline, and tuna drift net fisheries. Utilised for its high value fins, meat (salted), skin and cartilage.

Similar species:

Alopias superciliosus
Alopias superciliosus
Alopias superciliosus differs in lacking a deep groove on the nape (vs. a deep groove present on the nape) and eyes laterally positioned (vs. positioned dorsolaterally).

External links:

FishBase
The IUCN Red List of Threatened SpeciesTM