The Whitecheek lanternshark (Etmopterus alphus) is a shark belonging to the family Etmopteridae found in the western Indian Ocean. The Whitecheek lanternshark was named by Ebert, Straube, Leslie & Weigmann in 2016. ‘alphus’ referring to the unique white spot on the cheeks.
Family: Etmopteridae – Lantern Sharks
Genus: Etmopterus
Species: alphus
Phylum– Chordata
Class– Chondrichthyles
Subclass– Elasmobranchii
Common Name– Dogfish Sharks
Family– Etmopteridae
Common Name– Lantern Sharks
Genus– Etmopterus
Species– alphus
Status: IUCN Red List NOT EVALUATED
Average Size and Length: The maximum length of males has been recorded at 33.6 cm/1.1 feet, and females at 39 cm/1.3 feet.
Teeth and Jaw: The teeth are different in the upper and lower jaw. The upper teeth are multicuspid in three functional series. The functional teeth in the lower jaw are unicuspid in a single series, with approximately five series of replacement teeth in the upper and lower jaw. The multicuspid upper teeth are small and perpendicular, with a strong central cusp flanked by three lateral cusplets on each side, decreasing in size distally. The teeth in lower jaw are fused into a single row, blade-like with an oblique cusp. The tooth count in first row of the upper jaw is 30 (26–30) and in the first row of the lower jaw is 34 (31–34).
Denticles: The dermal denticles are linear.
Demographic, Distribution, Habitat, Environment and Range: The Whitecheek lanternshark can be found in the western Indian Ocean in Mozambique. They are marine pelagic-neritic at a depth range between 1,549-2,598 feet. They are subtropical at 18°S – 34°S, 37°E – 45°E.
Aesthetic Identification: The Whitecheek lanternshark is small and slender. The Whitecheek lanternshark can be separated from Blackbelly Lanternshark or Lucifer Shark– Etmopterus lucifer by several characteristics. The length of its anterior flank markings is much shorter than its posterior branch. The black flank markings are sharply defined by surrounding lighter to whitish lateral markings. There is a prominent white spot on each cheek and a single white stripe extending the length of the midback. There are 2 parallel rows of prominent dark pores extending between pectoral and pelvic fins. The closest family member geographically is the Sculpted Lanternshark– Etmopterus sculptus, which has its anterior branch longer than its posterior branch, with a thinner posterior flank marking, 0.2-0.4% (vs. 0.6-0.9% TL in E. alphus), it has a higher spiral valve count of 8-9 (vs. 5-7 in E. alphus); it differs from its closest morphological congener, the Australasian Slendertail Lanternshark or Moller’s Lanternshark– Etmopterus molleriby its shorter anterior (6.0-10.6% vs. 8.0-11.5% TL) and posterior (9.3-12.7% vs. 11.0-15.4% TL) flank-marking branches.
Biology and Reproduction: The vertebrae count is 84 – 90. Reproduction is unknown, but presumably ovoviviparous.
Behavioral Traits, Sensing and Intelligence: Unknown.
Whitecheek Lanternshark Future and Conservation: Not evaluated.
Whitecheek Lanternshark Recorded Attacks on Humans: Not a threat to humans.
Ebert, D.A., N. Straube, R.W. Leslie and S. Weigmann, 2016. “Etmopterus alphus n. sp.: a new lanternshark (Squaliformes: Etmopteridae) from the southwestern Indian Ocean”. Afr. J. Mar. Sci. 38(3):329-340.