African Coelacanth

The African coelacanth belongs to an ancient lineage of bony, lobe-finned fish. The species was believed to have gone extinct over 65 million years ago but was rediscovered off the coast of South Africa in 1938. The Tanzanian distinct population segment is thought to represent a single, isolated population of the species, having diverged approximately 200,000 years ago. The size of the population is likely small, with no connectivity to other populations. It also has late maturity and the longest generation time of any vertebrate. The main threats to the African coelacanth Tanzanian DPS include bycatch in shark gillnet fisheries and habitat destruction due to development. In 2016, NOAA Fisheries listed the DPS as threatened under the Endangered Species Act.

The coelacanth has several unique physical features. Most notably are its paired lobe fins that extend away from the body and move in an alternating pattern. The body of the fish appears iridescent dark blue in film or video footage but under natural light the color is light brown with white blotches throughout that have been used for individual identification. They also have thick, armor-like scales and a unique joint at the back of the skull that allows them to open their upper and lower jaws at the same time.

The coelacanth is a slow drift-hunter and eats a variety of benthic and epi-benthic prey, such as cephalopods, eels, cuttlefish, and deepwater fishes.

The Tanzanian distinct population segment of African coelacanth lives among deep, rocky terraces comprised of sedimentary limestone. In this habitat, coelacanths are thought to use submarine cavities and shelves that have eroded out of the limestone composite for shelter between 230 to 460 feet in depth and in temperatures around 68° F.

The average lifespan of coelacanths is estimated to be 48 years of age. Female coleacanths reach maturity between 16 and 19 years and give birth to live young after a very lengthy gestation period of 3 years, which is the longest gestation period of any vertebrate species.  

Bycatch

Historically, fisheries bycatch has been the most significant threat to the coelacanth. The Tanzanian distinct population segment in particular is subject to bycatch in the Tanzanian shark gillnet fishery, which has been expanding over the last decade.

Habitat Destruction

The Tanzanian distinct population segment may experience direct habitat loss due to deep-water port construction, including submarine blasting and channel dredging known to occur in coelacanth habitat.