A shark different from its other family members

The Shorttail Nurse shark, (Pseudoginglymostoma brevicaudatum), is a shark belonging to the family Ginglymostomatidae. It is the only member of the genus Pseudoginglymostoma. It is found in the tropical western Indian Ocean. Not much is known about this shark, but it has been observed in captivity as nocturnal. One has been living in captivity for 33 years and has been observed as egg-laying and can remain out of water for several hours.


Family: Ginglymostomatidae – Nurse Sharks

Genus: Pseudoginglymostoma 

Species: brevicaudatum


Phylum– Chordata

Class– Chondrichthyles


Common NameCarpet Sharks

Family– Ginglymostomatidae

Common NameNurse Sharks




Average Size and Length: Mature males have been measured between 55-60 cm/1.8 feet. The maximum recorded length was 75 cm/2.5 feet. An adult female has been in captivity for 33 years, and is 70 cm/2.3 feet long.

Teeth and Jaw: The mouth is small and subterminal. The Nurse shark possess an independent dentition, the simplest type of tooth arrangement found in sharks where there is no overlap between teeth. This allows forward movement of replacement teeth that is independent of adjacent teeth in the jaw. The teeth are serrated.

Head: The Shorttail Nurse shark can be distinguished from other Nurse sharks by having short nasal barbels. It has small eyes with small spiracles behind them.

Denticles: It has tough skin.

Tail: The caudal fin is long. The Shorttail Nurse shark can be distinguished from other Nurse sharks by having a shorter precaudal tail and caudal fin, which is less than 20% of the total length.

Demographic, Distribution, Habitat, Environment and Range: The Shorttail Nurse shark can be found in the west Indian Ocean in Tanzania, Kenya, Madagascar, and even possibly Mauritius and Seychelles (0°S – 27°S, 38°E – 58°E). They can be found around coral reefs, but the depths are unknown. They are tropical.

Ram-Suction Index: Nurse sharks are obligate suction feeders capable of generating suction forces that are among the highest recorded for any aquatic vertebrate to date. They may also shake their head violently to rip off smaller, digestible sizes of prey, or suck and spit. They suck prey in rapidly with their very small mouths and large pharynx.

Aesthetic Identification: The Shorttail Nurse shark has an elongated body and is dark brown without any spots or markings. The color of young sharks is unknown, but they do have a pattern of dark saddles on a lighter background. The pectoral fins are broad. The Shorttail Nurse shark can be distinguished from other sharks by having 2 rounded dorsal fins of equal size and an anal fin.

Biology and Reproduction: In captivity, they have been observed as egg-laying and are presumed oviparous, but this is not confirmed.

Behavioral Traits, Sensing and Intelligence: In captivity, the Shorttail Nurse shark is nocturnal. They have been reported to survive for several hours out of the water.

Shorttail Nurse Shark Future and Conservation: They are currently considered vulnerable.

Shorttail Nurse Shark Recorded Attacks on Humans: They are typically docile with humans, will bite if provoked or if needed to defend themselves. They have strong suction, and do not let go so their bites can pack a lasting and powerful punch.