GREEN LANTERNSHARK

Taxonomy:

Phylum– Chordata

Class– Chondrichthyles

Subclass– Elasmobranchii

Order– Squaliformes

Common Name– Dogfish Sharks

Family– Etmopteridae

Common Name– Lantern Sharks

Genus– Etmopterus

Species– virens

Status: IUCN Red List LEAST CONCERN

Average Size and Length: The newborn pups measure 9 cm/3.5 inches long. Mature males have been measured at 18 cm/7.1 inches and mature females at 22 cm/9 inches. The longest recorded has been 26 cm/10.2 inches.

Teeth and Jaw: The shape of the teeth in the upper and lower jaws differ. There are 29–34 tooth rows in the upper jaw, each tooth with a narrow central cusp flanked and generally have less than 3 pairs of cusplets. The lower jaw contains 24–32 tooth rows, their bases interlocking to form a continuous cutting surface and each tooth having a horizontal narrow cusp.

Head: The snout is short and blunt. The eyes are oval and very large. They are closer to the tip of the snout than the first gill slit. They have a green sheen. The spiracles are about the size of the gill slits. The nostrils are preceded by short skin flaps.

Denticles: The lateral trunk dermal denticles are short, stout, conical, hooked crowns that are wide-spaced and not arranged in rows. The dermal denticles cover the snout.

Tail: It has a moderately long tail. The dorsal margin is equal to the head length. The caudal fin is low and narrow, with an indistinct lower lobe and an upper lobe about as long as the head.

Demographic, Distribution, Habitat, Environment and Range: The Green lanternshark can be found in the northwest Atlantic, the northern Gulf of Mexico, the Caribbean and possibly Brazil. They have been spotted from Texas to Florida, Cuba, the Yucatan Peninsula, Honduras to Nicaragua, and from Panama to Venezuela. They can be found over the upper continental slopes between 643-3,002 feet, but typically they stay below 1,148 feet.

Diet: The Green lanternshark is known to attack very large squid in groups. They mainly feed on squid and octopus. They are frequently found with cephalopod eyes and beaks in their stomachs so large that the sharks would have had to distend their jaws considerably to swallow them.

Aesthetic Identification: The Green lanternshark is dwarf and moderately slender in size. It is dark-brown or grey-black in color dorsally, and black ventrally. There is an elongated broad black mark above and behind the pelvic fins. There are more marks at the tail base and along the axis. The gill slits are short; less than one third the eye length. The first dorsal fin has a grooved spine in front and originates over the trailing margin of the broad and rounded pectoral fins. The second dorsal fin also has a spine in front and is over twice the area of the first dorsal fin. The span between the second dorsal fin and the first dorsal fin are approximately equal to the distance between the snout tip and first gill slit. There is no anal fin.

Biology and Reproduction: They are presumably ovoviviparous with litters of between 1-3 pups. Males are thought to reach sexual maturity at a length of between 7.2–9.3 inches, and females at a length of between 8.7–10.1 inches.

The Green lanternshark has light emitting photophores in the ventral black markings like many other sharks in its family. These may aid in counter-illumination, as well as social communication. It has a yellow spot over its pineal gland that acts as a “window” for the detection of ambient light levels.

Behavioral Traits, Sensing and Intelligence: The Green lanternshark is social and may school or shoal. They are known to aggressively attack large prey in packs or groups, possibly in swarms.

Green Lanternshark Future and Conservation: They are of least concern at the moment because they aren’t evaluated and are common. They are possibly caught as bycatch and discarded by deepwater bottom commercial fishing vessels. They are not of commercial value.

Green Lanternshark Recorded Attacks on Humans: Not a threat to humans.