Idotea ochotensis Brandt 1851

How to Distinguish from Similar Species: Idotea aculeata is very similar but the palp of its maxilliped has 5 articles and it is found only from central California south. Idotea resecata has a concave posterior margin on the pleotelson.

We found this individual in an area of mixed boulders and sand, in an area with strong surf. Sometimes found on drifting seaweed and in brackish water.

Geographical Range: Japan, NE Asia to San Francisco

Depth Range: At least intertidal and shallow subtidal

As with other valviferan isopods, the uropods are ventral to the pleotelson, forming a valvelike covering over the pleopods. Idotea ochotensis has a body which is definitely dorsoventrally flattened and with 7 free pereonites. The lateral margins of the cephalon do not have a deep incision. The eyes are lateral. The pleon has 2 free pleonites plus a pleotelson. The pleon has a definite point on the posteromedian margin. The lataral margins of the pleon, and the posterior margins of the pleon on either side of the posteromedian point are often concave. The palp of the maxilliped has only 4 articles. Length to 4.2 cm, width to 1.6 cm.

intertidal - 20