INDONESIAN SHORTSNOUT SPURDOG

Endemic spurdog in Indonesia

The Indonesian shortsnout spurdog (Squalus hemipinnis) is a dogfish first described in 2007. It is a member of the family Squalidae, found off Indonesia.

 

Family: Squalidae – Dogfish Sharks

Genus: Squalus 

Species: hemipinnis

Taxonomy:

Phylum– Chordata

Class– Chondrichthyles

SubclassElasmobranchii

OrderSqualiformes

Common NameDogfish Sharks

Family– Squalidae

Common NameDogfish Sharks

GenusSqualus

Specieshemipinnis

Status: IUCN Red List NEAR THREATENED

Average Size and Length: The maximum recorded length for an unsexed male 1.7 feet. Longest recorded female has been 2.6 feet.

Head: The snout of the Indonesian Shortsnout spurdog is, like its name short. It is also quite narrow. The horizontal prenarial length is between 8.4-9.1% TL. The eyes are large with a length of between 5.1-5.6% TL. The secondary lobe of the anterior nasal flap is well developed.

Denticles: The flank denticles of the Indonesian Shortsnout spurdog are broadly unicuspidate to weakly tricuspidate. 

Tail: The caudal fin of the Indonesian Shortsnout spurdog has a short, broad caudal bar. There is an enlarged upper caudal blotch and there is fringe located on the lobe in juveniles.

Demographic, Distribution, Habitat, Environment and Range: The Indonesian Shortsnout spurdog can be found in the eastern Indian Ocean in Indonesia. They are mostly benthopelagic; usually found on or near the bottom of upper continental and insular slopes, but depth distribution is undetermined. Most say between 0-328 feet, but again undetermined.

Diet: The Indonesian Shortsnout spurdog mostly feeds on small fish. They are also known to eat cephalopods and crustaceans.

Aesthetic Identification: The Indonesian Shortsnout spurdog has a slender body. Its depth is 9-10.6% TL. They have small dorsal fins that are strongly raked. The first dorsal-fin spine is moderate, broad-based, while the second dorsal-fin spine is moderate, robust and broad-based. They have weakly falcate pectoral fins in adults, and its inner margin is short, being just 6.9-7.8% of the total length.

Biology and Reproduction: The Indonesian Shortsnout spurdog is viviparous, with yolk-sac dependency, meaning it is aplacental viviparous, or ovoviviparous. The give birth to between 3 -10 pups, but the gestation period is still unknown. Males mature at about 1.4 feet and females by 2 feet, with the largest embryo measured at 7.1 inches.

The monospondylous centra is 35-38, the precaudal centra is 72-76, and the total centra 96-100.

Behavioral Traits, Sensing and Intelligence: Unknown.

Indonesian Shortsnout Spurdog Future and Conservation: They are common to catch in deep water using long lines. It is caught for its meat, fins and liver oil. Because of its limited range it is near threatened.

Indonesian Shortsnout Spurdog Recorded Attacks on Humans: Not a threat to humans.

 

White, W.T., P.R. Last and G.K. Yearsley, 2007. Squalus hemipinnis sp. Nov. “a new short-snout spurdog from eastern Indonesia”. pp. 101-108. In P.R. Last, W.T. White and J.J. Pogonoski. “Descriptions of new dogfishes of the genus Squalus (Squaloidea: Squalidae)”. CSIRO Marine and Atmospheric Research Paper No. 014. 130 pp.