Kitefin Shark

The kitefin shark (or seal shark) is a squaliform shark that lives sporadically in different locations across the world. This shark is the largest luminous vertebrate in the world. It is fished commercially for its meat, skin, and most importantly, its sizable oil-filled liver, which is of commercial value to humans. 

Kitefin Shark Classification and Scientific Name

The scientific name of the Kitefin shark is Dalatias licha. The genus name “Dalatias” comes from the Greek word “dalos” or “dalou.” This means “torch.” The Kitefin shark is also known by other names such as seal shark, black shark, and darkie Charlie. 

Kitefin is a Squaliform shark. This order of sharks consists of 7 families and 126 identified species. It is the only species in the Dalatias genus. All members of the family Dalatiidae (where the kitefin shark belongs), alongside other families such as Eptomeridae and Zameus, exhibit some intrinsic bioluminescence. The seal shark is the largest of all the luminous shark species. 

Kitefin Shark Appearance 

The kitefin shark is a medium-sized fish with a cylindrical body. It has a short, blunt snout with thick lips that feature pleats or fringes. This blunt-faced shark has large eyes, characteristic of deep-water fishes. 

The seal shark has lobed fins. The dorsal fins are spineless, originating behind the rear tips of the pectoral fins. There are two dorsal fins, with the second being the larger. They also have a ventral caudal fin that is weak and lobed. Most of the posterior margins of the shark’s fin are translucent. 

The upper jaw has 16 to 21 rows of sharp teeth. The upper teeth have a small, spiked shape and curve slightly towards the edge of the shark’s mouth. The lower teeth are larger, numbering 17 to 20, with serrations on them. The bases of the teeth interlock to form a continuous, knife-shaped cutting surface. 

Kitefin sharks are typically uniform dark brown or gray. Sometimes, they have faint-black spots on their backs. The average length of kitefin sharks is between 1 to 1.4 meters. Similarly, their average weight is about 8kg. The maximum reported length is 1.8m. 

Kitefin sharks are bioluminescent. Scientists believe that the greenish-blue glow of this fish (typically concentrated on its belly and underside) is a type of camouflage that helps the shark blend in with the light from above. 

Distribution, Population, and Habitat

The Kitefin shark is primarily a bycatch species in most locations. However, they are typically caught with a trawl or hook in certain regions of the world, such as Japan and Portugal, mainly for their flesh and oil. In these regions, overfishing and low reproductive rates contribute to a decline in the population of the seal shark species. This is why the species has been categorized as “Vulnerable” by the International Union for Conservation of Nature. Experts are certain that the productivity level of this species is low. However, there isn’t sufficient information about their biomass or population trends.

Where to Find Kitefin Shark and How to Catch Them

Kitefin sharks are sparsely distributed in warm and temperate regions all over the world. They are most commonly found in isolated populations in the Atlantic, Indian, and Pacific Oceans. This species of shark is naturally solitary and epibenthic, which means they live on or just above the bottom sediments of the ocean. They prefer deepwater habitats, usually about 656.2 ft (200 m) deep. However, they have been found as far out as 5905.5 ft (1800 m) and in shallow depths of about 121.4 ft (37m).  

Predators and Prey

Given the fact that the seal shark isn’t a fast swimmer, it is mostly a scavenger that feeds on small fish and crustaceans. However, it is also equipped with strong and sharp teeth modified for grabbing and cutting. This means this 3 to 4-foot shark also has what it takes to be a predator. 

What Eats Kitefin Shark

The kitefin shark does not have a lot of natural predators. Humans in some regions of the world fish kitefin sharks for their meat, skin, and liver oil. Due to Human exploitation and the species’ low reproductive rate, the International Union for Conservation of Nature (IUCN) considers them a vulnerable species.

What Does Kitefin Shark Eat?

Kitefin sharks are not the fastest swimmers. However, they do have strong bites and large teeth. They are powerful predators that typically hunt alone. They can take a wide range of prey, including bony fishes, cartilaginous fishes like sharks and rays, cephalopods, crustaceans, and polychaete worms. Kitefin sharks can bite into sharks that are larger than themselves with their large, powerful teeth. 

Reproduction and Lifespan

These shark species reproduce through an aplacental viviparous process. The embryos hatch in the mother’s uterus. They sustain themselves on unfertilized eggs produced by the mother. Adult females have two functional uteruses. Although their uterus is not divided into compartments, they may give birth to between 10 to 16 young. 

The young seal sharks are born at a length of about 3.5 to 4.5m. Their exact size varies from one geographic location to the other. We do not know the exact gestation period, but some estimates have placed it at up to two years. 

Kitefin Shark In Fishing And Cooking

Although it has no commercial value in the western Atlantic countries, the Kitefin shark has a long history of human exploitation in certain regions of the world. In the Eastern Atlantic region (notably Japan), people eat seal sharks for their meat and also process them into fishmeal. Similarly, liver oil from the species is useful in Portugal, Japan, and South Africa.

They can make the skin of this shark into a type of shagreen, which is useful for jewelry and furniture. They also make a special type of polished Spanish leather known as “boroso” from the seal shark’s skin.