Branchellion
Branchellion is a genus of parasitic lampreys in the family Piscicolidae. It comprises two species, Branchellion torpedinis and Branchellion sanguinea. Both species are commonly called “fish lice” due to their parasitic nature and their close association with marine fish. While they are classified as lampreys, Branchellion species lack the typical, pronounced oral disc and teeth associated with other lampreys. Instead, they have a smaller, sucker-like mouth with rows of tiny teeth used to attach to their host.
Characteristics
Branchellion species are characterized by their flattened, oval body shape, which is adapted for clinging to the skin of their hosts. They possess a pair of large, well-developed eyes and a prominent dorsal fin. The body is covered in small, scales that give it a rough texture. Their coloration varies depending on the species and their environment. They are generally brown or gray with darker spots or stripes. These lampreys also possess a unique respiratory system. They have gills, but they also breathe through their skin, which allows them to absorb oxygen directly from the water.
Environment
Branchellion species are found in a variety of marine habitats, including coastal waters, estuaries, and the open ocean. They are typically found attached to the skin of their hosts, which include a wide range of marine fish, such as sharks, rays, and bony fish. These lampreys are often found in warmer waters, with the species B. sanguinea being more prevalent in the Mediterranean Sea and the North Atlantic Ocean, while B. torpedinis is found in the Mediterranean and the northeastern Atlantic.
Life Cycle
The life cycle of Branchellion species is similar to other lampreys. They begin as larvae, called ammocoetes, which live in the sediment of marine environments. They are filter feeders, consuming small organisms and organic matter. After a period of growth, they undergo metamorphosis, transforming into the adult parasitic form. This transformation involves the development of a sucker-like mouth, the loss of the larval feeding apparatus, and the development of reproductive organs. Once adults, they attach to a host, feeding on its blood and bodily fluids until they are ready to reproduce.
References
* Fishbase.se * Wikipedia * National Center for Biotechnology Information