BLURRED SMOOTH LANTERNSHARK OR BLURRED LANTERNSHARK

Taxonomy:

Phylum– Chordata

Class– Chondrichthyles

Subclass– Elasmobranchii

Order– Squaliformes

Common Name– Dogfish Sharks

Family– Etmopteridae

Common Name– Lantern Sharks

Genus– Etmopterus

Species– bigelowi

Status: IUCN Red List LEAST CONCERN

Average Size and Length: They are born less that 16 cm. Mature males are around 1.3 feet. Mature females are around 1.6 feet. The longest recorded is 2.2 feet.

Teeth and Jaw: The mouth has long furrows at the corners that extend halfway to the first of five gill slits. There are multicuspid pointed upper teeth and knife-like lower teeth. There are 19–24 tooth rows in the upper jaw, each with a narrow central cusp flanked by 2–4 pairs of smaller cusplets, increasing in number with age in males over 18 inches long. There are 25–39 tooth rows in the lower jaw, each tooth with a smooth-edged, knife-like cusp and their bases interlocked to form a single cutting surface. The teeth of males over 17 inches long and females over 14 inches long become more erect with age.

Head: The head is broad. The snout is thick and flat and almost wedge-shaped tapering to a point. It has a small white blotch on the top of the head. The nostrils are large, with short flaps of skin in front. The eyes are large, oval in shape with a deep anterior notch in the orbit.

Denticles: The Blurred Smooth lanternshark is one of the only sharks in its family with flat, block-like dermal denticles that make the skin feel smooth to the touch. The small, blocky dermal denticles are densely but irregularly arranged, each with a flat, truncate crown.

Tail: The tail is long. The caudal peduncle is narrow, leading to a caudal fin with a well-developed lower lobe and a broad upper lobe with a ventral notch near the tip.

Demographic, Distribution, Habitat, Environment and Range: In the Atlantic Ocean, it is known from the Gulf of Mexico to Argentina, and off western and southern Africa. In the Indo-Pacific, it has been reported from off Okinawa and Australia, as well as on the Emperor and Hancock Seamounts in the central North Pacific and over the Nazca Plate off Peru. The Blurred lanternshark haS been caught around the world over continental and insular shelves and slopes, submarine ridges, and seamounts from 135-3,281 feet or more. They are partly epipelagic. They can occur near the surface in the open ocean from 361-2,297 feet.

Diet: The diet of the Blurred Smooth lanternshark consists of squid, smaller dogfish sharks, lanternfishes, and fish eggs.

Aesthetic Identification: The Blurred Smooth lanternshark or Blurred lanternshark is a fairly large and slender shark in comparison to other sharks belonging to its family. It is dark brown to blackish on top and even darker below. The fins have light edges. There are photophores present, but they aren’t in conspicuous dark bands. The first dorsal fin is close to the pectoral than the pelvic fins, and has a straight, grooved spine in front. The second dorsal fin is half again as tall as the first and has a longer, curved spine. The pectoral fins are rounded at the tips, with the distance between them and the medium-sized, angular pelvic fins about equal to the distance between the dorsal fins. There is no anal fin.

Biology and Reproduction: Poorly known, but presumably ovoviviparous. The Blurred Smooth lanternshark is very similar to the Smooth lanternshark, but is larger and can be reliably differentiated by the number of turns in the spiral valve intestine (16–19 versus 10–13).

Behavioral Traits, Sensing and Intelligence: Unknown.

Blurred Smooth Lanternshark Future and Conservation: They are of least concern. They are of little importance to fisheries.

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