NARROWFIN SMOOTHHOUND OR FLORIDA SMOOTHHOUND
A Florida shark that has pavement teeth and segregates by size and sex
The Narrowfin smoothhound or Florida smoothhound (Mustelus norrisi) is a shark belonging to the family Triakidae. It is found on the continental shelves of the subtropical western Atlantic, from Florida and the northern Gulf of Mexico to Venezuela, and also southern Brazil. It is plain grey in color with pavement like teeth. This shark may be migratory and does segregate by size and sex.
Family: Triakidae – Houndsharks
Genus: Mustelus
Species: norrisi
Phylum– Chordata
Class– Chondrichthyles
Common Name– Ground Sharks
Family– Triakidae
Common Name– Houndsharks
Genus– Mustelus
Species– norrisi
Status: IUCN Red List DATA DEFICIENT
Average Size and Length: They are born at 29-30 cm/11.4-11.8 inches. Mature males have been measured between 57-61 cm/1.8-2 feet, and mature females at 65 cm/2.1 feet. The maximum recorded is 98 cm/3.2 feet.
Weight: It weighs on average 30.8 pounds.
Teeth and Jaw: The mouth is long, and the upper labial furrows are shorter than the lower labial -furrows. The teeth are low crowned, and pavement like with weak cusps.
Head: It has a short and narrow head, and it is smaller and narrower than the head of the Dusky smoothhound. It is also narrow internarial. Their eyes are somewhat large with spiracles behind them.
Denticles: The dermal denticles are irregularly spaced sometimes overlapping as well as leaving areas of skin visible. They have 2-6 longitudinal ridges and are occasionally weakly notched.
Tail: The caudal fin is asymmetrical.
Demographic, Distribution, Habitat, Environment and Range: The Narrowfin smoothhound or the Florida smoothhound can be found in the west Atlantic in the USA in the Gulf of Mexico, as well as the southern Caribbean coast of Colombia and Venezuela, as well as southern Brazil (32° N and 36° S). They can be found on the continental shelf in the sand and or mud on the bottom. They are found close inshore to more than 276 feet, but most stay inshore less than 180 feet. It is subtropical demersal.
Diet: They eat crabs and shrimp, and small fish.
Potential predators of the Narrowfin smoothhound or Florida smoothhound are larger sharks, like the Dusky shark, the Blacktip shark, and the Great hammerhead shark.
Aesthetic Identification: The Narrowfin smoothhound or Florida smoothhound is a grey shark and is somewhat large in its genus. The fins are falcate. In newborn sharks, the dorsal and caudal fin tips are dusky in color. The ventral side is a lighter dirty white. The first dorsal fin begins well posterior to the pectoral axil. The second dorsal fin is significantly larger than the anal fin. The pectoral fins are small.
Biology and Reproduction: They are viviparous with a yolk-sac placenta, having between 7-14 pups per litter.
A parasite of this shark is the copepod Perissopus dentatus, which can be found on the trailing edge of fins.
Behavioral Traits, Sensing and Intelligence: They segregate by size and sex off the coast of Florida. Adult males go inshore during the winter. They may be migratory in the Gulf of Mexico, moving inshore to less than 55m in the winter, and offshore during the other seasons.
Narrowfin Smoothhound or Florida Smoothhound Future and Conservation: There is not enough data to evaluate. It is known to have low resistance. Even without fishing pressure the species’ population size would require 14 years to double. They are common among their range, but there isn’t any information on the importance to fisheries.
Narrowfin Smoothhound or Florida Smoothhound Recorded Attacks on Humans: Not a threat to humans.