Recently described endemic species of shark

The Gulf of Mexico smoothhound, or sometimes just called the Gulf smoothhound (Mustelus sinusmexicanus) is a shark belonging to the family Triakidae. It is apparently endemic to the Gulf of Mexico in the USA and in Mexico. It is often confused with the Dusky smoothhound. Not much is known about this recently described species of shark.


Family: Triakidae – Houndsharks

Genus: Mustelus 

Species: sinusmexicanus


Phylum– Chordata

Class– Chondrichthyles


Common NameGround Sharks

Family– Triakidae

Common NameHoundsharks




Average Size and Length: They are born between 39-43 cm/1.2-1.4 feet. Mature males have been measured between 70/2.3 feet and less than 80 cm/2.6 feet. Females have been measured less than 118 cm/3.8 feet at maturity. The maximum recorded was 140 cm/4.6 feet.

Teeth and Jaw: The upper labial furrows are longer than the lower labial furrows. The teeth are pavement like with high crowns, unlike some of the other sharks in its genus, the Narrowfin smoothhound and the Dusky smoothhound and others with low crowned teeth.

Head: The head and the snout are short. The internarial space is broad. The eyes are large, but close set.

Tail: The ventral caudal lobe is somewhat expanded. There is a notch in the caudal fin.

Demographic, Distribution, Habitat, Environment and Range: Like in its name, the Gulf of Mexico smoothhound can be found in the Gulf of Mexico in the USA and in Mexico. Specifically, from off of Panama City, Florida to the Bay of Campeche. They can be found offshore on the continental shelf and upper slope between 118-751 feet, but typically found between 138-299 feet. They are not found in shallow water. They are pelagic oceanic found in tropical waters.

Aesthetic Identification: The Gulf of Mexico smoothhound is a large, slender, grey unspotted shark. The ventral side of the shark is white. The dorsal fins are unfringed. The first dorsal fin is large and non-falcate, but strong. The young have dusky tipped dorsal and caudal fins. It is often confused with other sharks in its genus, especially the Dusky smoothhound.

Biology and Reproduction: Their biology is poorly known. They are apparently placental viviparous having eight pups per litter.

Behavioral Traits, Sensing and Intelligence: Unknown.

Gulf of Mexico Smoothhound Future and Conservation: There is currently not enough data to evaluate. This is a recently described species, and supposedly endemic.

Gulf of Mexico Smoothhound Recorded Attacks on Humans: Not a threat to humans.