Psalidopodidae

Lore & Background

The family Psalidopodidae contains only the genus Psalidopus, which is divided into three species. Psalidopus barbouri occurs on continental and insular slopes from Florida, the Bahamas and the Gulf of Mexico to parts of the Caribbean Sea, possibly extending as far south as Suriname. It lives on steeply sloping soft muddy bottoms, sometimes mixed with sand, at depths of 400–800 m, where temperatures range from 6.1 to 10.0 °C. Adults have a carapace length of 13–32 mm, with total length up to 5.5 times the carapace length.

Psalidopus huxleyi occurs across the Indian Ocean, including the Laccadive Sea, off southern India, the Andaman Sea and the Timor Sea, as well as in the western Pacific Ocean from southern Japan to the Philippines, the Sulu Sea, and the Celebes Sea. It lives on steeply sloping bottoms of various compositions at depths of 500–100 m, with temperatures from 5.9 to 13.6 °C. Its carapace is 10–30 mm long.

Psalidopus tosaensis lives at greater depth (c. 2800 m) and lower temperature (1.6 °C) than either of the other species. Although geographically closer to P. huxleyi, it appears more closely related to P. barbouri.

Reader's Guide

The family Psalidopodidae is significant as the sole representative of the superfamily Psalidopodoidea, indicating a distinct evolutionary lineage among marine shrimp. The article describes three species with distinct geographic ranges: one in the western Atlantic and two in the Indo-Pacific. The species show variation in depth and temperature preferences, with Psalidopus tosaensis inhabiting much greater depths (c. 2800 m) and colder waters (1.6 °C) than its relatives. Notably, despite its geographic proximity to Psalidopus huxleyi, Psalidopus tosaensis appears more closely related to the Atlantic species Psalidopus barbouri, suggesting a complex biogeographic history. The family's members occupy steeply sloping bottoms, with Psalidopus barbouri specifically associated with soft muddy substrates. The size range across species is modest, with carapace lengths from 10 to 32 mm. The family's legacy lies in its taxonomic uniqueness and the ecological adaptations of its species to deep-sea environments across different ocean basins.

Did You Know?

• Psalidopodidae is the only family in the superfamily Psalidopodoidea.
• Psalidopus tosaensis lives at about 2800 m depth, deeper than the other two species.
• Psalidopus barbouri occurs from Florida to the Caribbean Sea, possibly as far south as Suriname.
• Psalidopus tosaensis appears more closely related to the Atlantic species P. barbouri than to the geographically closer P. huxleyi.