Tiny shark with a tadpole-like shape

The Lollipop catshark (Cephalurus cephalus) is a little-known species of deep-sea catshark, belonging to the family Scyliorhinidae. It is a bottom-dwelling shark. They can be easily identified by its tadpole-like shape with a greatly expanded, rounded head and narrow body. The large head houses expanded gills, which are thought to be an adaptation for hypoxic conditions or low oxygenated areas. The Lollipop catshark makes our list at 9th in the PSD ranked World’s Smallest Sharks. Check it out here.


Family: Scyliorhinidae – Catsharks

Genus: Cephalurus 

Species: cephalus


Phylum– Chordata

Class– Chondrichthyles


Common NameGround Sharks

Family– Scyliorhinidae

Common NameCatsharks




Average Size and Length: They are born around 10 cm/3.9 inches. Mature sharks measure around 19 cm/7.5 inches and the longest recorded has been 28 cm/11 inches.

Current Rare Mythical Sightings: The Lollipop catshark was originally described by American ichthyologist Charles Henry Gilbert as Catulus cephalus, in the 1892 14th volume of Proceedings of the United States National Museum. His description was based on a 24 cm/9.4-inch-long adult male caught from a depth of 841 m/2,759 feet off Clarion Island in the Revillagigedo Islands. In 1941, Henry F. Bigelow and William C. Schroeder created the new genus Cephalurus for this species.

Based on morphological and molecular phylogenetic evidence, Cephalurus is thought to form a clade with the genera Asymbolus, Parmaturus, Galeus, and Apristurus. However, different authors disagree on the interrelationships within this group; molecular data supports Cephalurus and Parmaturus as sister groups.

Teeth and Jaw: The mouth has a pair of furrows at the corners that curl around from the upper to the lower jaw. The widely spaced teeth have a large central cusp flanked by 1–3 cusplets on both sides. The upper teeth are straight while the lower teeth are curved somewhat outward. There are numerous small papillae on the tongue and roof of the mouth, and a light-colored membrane lining the inside of the mouth.

Head: The head is expanded, rounded and flattened and compromises a 3rd of the total length of the shark. The snout is very short and blunt, with widely spaced nostrils flanked by moderately developed flaps of skin. The large eyes are oval in shape and followed by prominent spiracles. The eyes are an iridescent green.

Denticles: The skin is very thin, giving them the soft feel. The skin is delicate and sparsely covered by thorn-like dermal denticles interspersed with narrower hair-like denticles that become more numerous on the back.

Tail: The caudal fin is low, with an indistinct lower lobe and a shallow ventral notch near the tip of the upper lobe.

Demographic, Distribution, Habitat, Environment and Range: The Lollipop catshark can be found in southern Baja California and the Gulf of California, Mexico (32°N – 15°S). They can be found on the upper continental slope and outermost shelf, on or near the bottom between 509-3,041 feet. The expanded gill areas suggest that the Lollipop catshark is adapted to areas of the seabed with low dissolved oxygen levels. They are considered bathydemersal.

Diet: More than likely they eat crustaceans and then fish.

Aesthetic Identification: The Lollipop catshark is a very small, unmistakable shark. They are un-patterned, brownish-grey, sometimes lightening to almost white at the dorsal, pectoral, and pelvic fin margins, and are shaped like a tadpole. Like the head, the gill region is also expanded. The five pairs of gill slits are distinctive, being strongly arched forward. They are small, slender and very soft. They are almost gelatinous. The body and tail are also slender. There are two small dorsal fins and an anal fin. The first dorsal fin origin is slightly in front of the pelvic fin origins. The second dorsal fin is about as long and slightly lower than the first, and is positioned opposite the anal fin. The dorsal, pelvic, and anal fins have convex leading and nearly straight trailing margins. The pectoral fins are angular, twice as long as wide, and originate beneath the fourth gill slit.

Biology and Reproduction: They are ovoviviparous. The Lollipop catshark retains its very thin-walled egg cases in the uterus until they hatch. There are 2 young per litter. Birthing possibly takes place in early summer.

The enlarged gill region and expanded gill filaments of the Lollipop catshark suggest that it is adapted for living in deep-sea basins with very low levels of dissolved oxygen and perhaps also high temperatures and salinity.

Behavioral Traits, Sensing and Intelligence: Unknown.

Lollipop Catshark Future and Conservation: There is not enough data to evaluate. They are not of any interest to fisheries. It is occasionally taken as bycatch.

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