Poissontidae

Poissontidae is a taxonomic family of small marine crustaceans within the order Amphipoda. The family comprises several genera and a number of described species, most of which occur in coastal and nearshore habitats. As with many amphipod families, Poissontidae is primarily defined by a combination of morphological characters and genetic data used in modern classifications.

Description: Members are generally small and have a laterally compressed body typical of amphipods. They typically lack a large carapace and possess a segmented abdomen with diverse adaptations for living among sediment, sea grasses, or submerged surfaces.

Distribution and habitat: Poissontidae species are found in temperate and tropical coastal waters around the world. They inhabit a range of microhabitats, including seagrass beds, algal mats, coral rubble, intertidal flats, and subtidal sediments. Some species are adapted to interstitial life in fine sands or tidal pools.

Ecology and life history: Species in the family are generally detritivores or microherbivores, contributing to nutrient cycling in benthic ecosystems. Reproduction follows typical amphipod patterns, with brood care by females; in many genera eggs are carried in a marsupium until hatching. Development is direct in several lineages, while others have planktonic larval stages.

Taxonomy and phylogeny: The circumscription of Poissontidae has changed as new taxa are described and molecular data accumulate. The exact relationships within Amphipoda remain under study in some classifications, and Poissontidae is treated differently by various taxonomic treatments. The type genus has historically shaped the concept of the family.

Conservation and significance: There is limited species-level information on conservation status. At a community level, Poissontidae species contribute to detrital processing and serve as prey for larger invertebrates and fish. Habitat disturbance, pollution, and climate change are potential threats to local populations.