The Narrowhead catshark (Bythaelurus tenuicephalus) is a shark belonging to the family Scyliorhinidae. This species is described based on one adult and one juvenile male specimen from off Tanzania and Mozambique in the western Indian Ocean.
Family: Scyliorhinidae – Catsharks
Genus: Bythaelurus
Species: tenuicephalus
Phylum– Chordata
Class– Chondrichthyles
Common Name– Ground Sharks
Family– Scyliorhinidae
Common Name– Catsharks
Genus– Bythaelurus
Species– tenuicephalus
Status: IUCN Red List NOT EVALUATED
Average Size and Length: The maximum recorded length is 30 cm/11.8 inches, but not many specimens have been examined.
Teeth and Jaw: The Narrowhead catshark differs from the Broadhead catshark in that they have larger oral papillae. In contrast to the Mud catshark, the Narrowhead catshark has numerous oral papillae. The upper jaw has 67 – 76 and lower jaw has 62 – 64 rows of small tricuspidate teeth.
Head: The Narrowhead catshark differs from its congeners by its slender head and snout, which is only slightly bell-shaped in dorsoventral view without distinct lateral indention vs. distinctly bell-shaped snouts with a strong lateral indention anterior to outer nostrils. The Narrowhead catshark differs from the Broadhead catshark in that it has a shorter snout. Compared to the Bristly catshark, the Narrowhead catshark has a longer snout. In contrast to the Mud catshark, the Narrowhead catshark has shorter anterior nasal flaps.
Demographic, Distribution, Habitat, Environment and Range: The Narrowhead catshark has been found off Tanzania and Mozambique in the western Indian Ocean. They are considered tropical pelagic-oceanic found at depths between 1,519-1,805 feet.
Aesthetic Identification: The Narrowhead catshark differs from the Broadhead catshark in that it attains a smaller maximum size and it has a color pattern of fewer and smaller blotches. The Narrowhead catshark has a longer dorsal-caudal space than the Bristly catshark. In contrast to the Mud catshark, the Narrowhead catshark attains a smaller size and has a blotched coloration, a longer caudal fin, and a shorter pelvic anal space.
The coloration in preservative is bicolored with an abrupt lateral demarcation of medium brown dorsal and whitish ventral color, about five indistinct darker blotches on dorsolateral surface at gill slits and dorsal and caudal fins; fins lighter towards their margins.
Biology and Reproduction: The Narrowhead catshark differs from the Broadhead catshark in that it has broader claspers without knob-like apex and with a smaller envelope and a subtriangular exorhipidion. The Narrowhead catshark has broader clasper without knob-like apex than the Bristly catshark. In contrast to the Mud catshark, the Narrowhead catshark shorter and broader claspers.
The Narrowhead catshark has fewer vertebral centra than the Bristly catshark.
monospondylous trunk vertebrae centra 38 – 40, diplospondylous precaudal centra 43 – 50, total centra about 133 – 138.
Behavioral Traits, Sensing and Intelligence: Unknown.
Narrowhead Catshark Future and Conservation: They are not evaluated.
Narrowhead Catshark Recorded Attacks on Humans: Not a threat to humans.