EDMUND’S SPURDOG

A rarely researched dogfish in the eastern Indian Ocean

Edmunds spurdog (Squalus edmundsi) is a dogfish described in 2007. It is a member of the family Squalidae, found in Asia. The length of the longest specimen measured is 2.8 feet.

 

 

Family: Squalidae – Dogfish Sharks

Genus: Squalus 

Species: edmundsi

Taxonomy:

Phylum– Chordata

Class– Chondrichthyles

SubclassElasmobranchii

OrderSqualiformes

Common NameDogfish Sharks

Family– Squalidae

Common NameDogfish Sharks

GenusSqualus

Speciesedmundsi

Status: IUCN Red List NEAR THREATENED

Average Size and Length: The maximum known length is 2.3 feet for an unsexed male. Known female length has been 2.8 feet.

Head: Edmund’s spurdog has a narrowly triangular snout with a moderately long preoral length of 2.0-2.44 times the horizontal prenarial length. This is 10.3-10.8% TL. The mouth width is 1.56-1.81 (1.73) times the horizontal prenarial length. There are weakly bifurcated anterior nasal flaps.

Denticles: The flank denticles are strongly tricuspidate. 

Tail: The caudal bar is oblique, extending along the base of lower lobe to the caudal fork. It is less than 0.1-0.2 of the posterior margins of the upper lobe. The upper caudal fringe is narrow, with a large dark saddle, distinctly closer to tip of lobe than its base.

Demographic, Distribution, Habitat, Environment and Range: Edmund’s spurdog can be found in the eastern Indian Ocean in western Australia and Indonesia. They are pelagic-oceanic in tropical waters at a depth range of 669-2,789 feet, but typically stay between 984-1,640 feet.

Aesthetic Identification: The Edmund’s spurdog has a moderately elongated body. The pre-first dorsal fin length is between 27.7-30.0% (28.5%) TL. The pre-second dorsal fin length is between 60.2-62.9% (61.3%) TL. The interdorsal space is between 23.5-25.6% (24.7%) TL. The first dorsal fin is large and upright and its height is between 7.0-8.0% TL. The first dorsal-fin spine is strong, upright and broad-based. The second dorsal-fin spine is long and moderately broad-based. The pre-pectoral length is between 21.9-23.1% (22.6%) TL. The pelvic-caudal space is between 25.0-26.7% (25.9%) TL. The pectoral fin of adult individuals is not falcate. The pectoral-fin inner margin is relatively short, between 6.4-7.1% TL.

Biology and Reproduction: Monospondylous centra 43-44, precaudal centra 86-91, total centra 1130-120.

Behavioral Traits, Sensing and Intelligence: Unknown.

Edmund’s Spurdog Future and Conservation: Edmund’s spurdog is commonly caught by demersal longline fisheries operating in deep-water. It is utilized for its meat, fins and liver oil.

Edmund’s Spurdog Recorded Attacks on Humans: Not a threat to humans.