Camallanida

Camallanida is an order of parasitic nematodes that infect the digestive tracts of various aquatic vertebrates. These worms are characterized by their prominent, often camallanid-shaped buccal capsules, which are muscular structures used for attachment to the host's intestinal wall. The life cycle typically involves an intermediate host, such as crustaceans or small fish, which ingest the infective larval stages. The definitive host then becomes infected by consuming the intermediate host. Camallanid nematodes can cause a range of pathological effects in their hosts, including inflammation, reduced growth, and nutrient malabsorption. They are found worldwide in freshwater and marine environments, affecting a diverse array of fish, amphibians, reptiles, and occasionally mammals. Some species, like Camallanus cotti, are commonly encountered in aquarium fish. The classification within Camallanida includes several families, with significant research focusing on their host specificity, evolutionary relationships, and potential impact on host populations. Diagnosis often involves fecal examination to identify characteristic eggs or direct observation of adult worms during necropsy. Treatment strategies may include anthelmintic drugs, though efficacy can vary depending on the specific species and host.