Dolopsidae

Dolopsidae is a family of parasitic crustaceans belonging to the order Branchiura, commonly known as fish lice. These ectoparasites are primarily associated with freshwater fish, particularly species within the order Cypriniformes, such as carp and catfish. Dolopsidae members are characterized by their elongated, flattened bodies, which allow them to attach firmly to their hosts.

The most well-known genus within this family is *Dolops*, which includes several species that infect freshwater fish globally. These parasites attach themselves to the gills, fins, or body surface of their hosts, feeding on blood and other bodily fluids. Their presence can lead to stress, reduced growth, and increased susceptibility to infections in the host fish.

Dolopsidae exhibit a complex life cycle involving both parasitic and free-swimming stages. The adults are permanently attached to fish, while their larvae, known as nauplii, are free-swimming and eventually settle onto a host to develop further. The family is distinguished from other branchiuran parasites by its unique anatomical features, such as the absence of a distinct head region and the presence of specialized attachment structures.

These parasites are of ecological and economic significance due to their impact on fish populations. In aquaculture, heavy infestations can cause significant economic losses, prompting the development of control measures such as chemical treatments, mechanical removal, and the use of resistant fish strains. Research into Dolopsidae continues to provide insights into their biology, host-parasite relationships, and potential impacts on aquatic ecosystems.