This shark finds its home near to the Amazon

The Slender catshark (Schroederichthys tenuis) is a species of catshark belonging to the family Scyliorhinidae. It is found on the upper continental slope off the coast of Suriname and Brazil, just north and south of the mouth of the Amazon River at depths between 236-1,476 feet. The Slender catshark is similar to the Lizard catshark, but there are noticeable differences.


Family: Scyliorhinidae – Catsharks

Genus: Schroederichthys 

Species: tenuis


Phylum– Chordata

Class– Chondrichthyles


Common NameGround Sharks

Family– Scyliorhinidae

Common NameCatsharks




Average Size and Length: Each egg case measures 3.5 x 1.7 cm. Mature males measure between 40-47 cm/1.3-1.5 feet. Mature females measure between 37-46 cm/1.2-1.5 feet. The maximum recorded has been 47 cm/1.5 feet.

Teeth and Jaw: The mouth is narrow. Males have a much longer and more angular mouth than females do. Males have much larger teeth than the females. The upper teeth are 3-5 cusp, small, wide and burr or star-like with a sharp, pointed central cusps, and the surrounding cusps smaller. The bottom teeth are 3 cusped, with the central cusp almost the size of the two surrounding cusps.

Head: The snout is broad. The anterior nasal flaps are narrow and lobate.

Denticles: The dermal denticles are pointed. Tis differs from the Lizard catshark’s round ones.

Tail: The upper lobe of the tail fin is much larger than the lower lobe.

Demographic, Distribution, Habitat, Environment and Range: The Slender catshark can be found in the western Atlantic in South America in Surinam and northern Brazil. They are north, and just south of the Amazon River mouth (4°N and 2°S). They are found on or near the bottom on the outer continental shelf and upper continental slope between 236-1,476 feet. They are considered bathydemersal.

Diet: They eat foraminifera, crustaceans, small fish, squid, sponges, gastropods, and possibly other smaller sharks. Foraminifera, sponges, and dermal denticles of other sharks were found in stomach contents of examined sharks.

Aesthetic Identification: The Slender catshark, like its name, is obviously slender. It has a light brown body with many small dark spots outlining and scattered between seven and eight conspicuous dark saddles, four between the dorsal fins. There are no white spots. The first dorsal fin origin is slightly behind the pelvic fin insertions. The second dorsal fin is larger than the first. The Lizard catshark has a longer distance between the two dorsal fins and a longer distance between the pelvic and anal fins.

Biology and Reproduction: They are oviparous. They lay eggs in pairs. The egg cases have tendrils at each end used by the female to attach them to the sea bed or rocks.

The vertebrae count of the Slender catshark is between 108-113, while the Lizard catshark as between 120-123.

Behavioral Traits, Sensing and Intelligence: Unknown.

Speed: More than likely slow moving.

Slender Catshark Future and Conservation: There is not enough data to evaluate. The population size and trend are unknown but the shark has a limited range and may be vulnerable to pollution in the Amazon River water. It is sometimes caught as bycatch by artisan fishermen while they are trawling for shrimps and other commercially fished catsharks.

Slender Catshark Recorded Attacks on Humans: Not a threat to humans.