Description: This isopod has a long, rather robust body, which is oblong in shape with almost parallel sides. There are obvious segments aside from at the posterior of the animal where some segments are fused. Here the pleon and telson fuse to form the pleotelson which has straight sides and an almost straight end. Males grow 8-30 mm long while females reach 9-18 mm. It is usually a uniform grey or brown They have two short antennae and conspicuous black eyes.

Habitat: Usually found in debris originating in Gulf Stream that has stranded on western open-facing coasts.

Distribution: Scattered records around Britain and Ireland. None on eastern coasts.

Similar Species: Could be confused with other isopods, especially Idotoea species. More robust form and straightness of pleotelson helps identify this species.

Key Identification Features:

• Long, robust body – oblong, almost parallel sides.
• Pleotelson with straight sides and almost straight end.
• Uniform grey or brown in colour.

Distribution Map from NBN: Idotea metallica at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Idotea metallica at iNaturalist World Species Observations database.

GBIF data for Idotea metallica

WoRMS: Idotea metallica at World Register of Marine Species. Accepted name: Idotea metallica Bosc, 1801. AphiaID: 119047.

Classification: Biota; Animalia; Arthropoda; Crustacea; Multicrustacea; Malacostraca; Eumalacostraca; Peracarida; Isopoda; Valvifera; Idoteidae; Idotea