Tripneustes gratilla elatensis 1

Description:

Tests of Red Sea T. g. elatensis showing the rather smooth appearance of the test. arrows show the paucity of spine tubercles - less than 1 spine for each interambulacral plate (most oceanic Tripneustes - T. gratilla, T. depressus and T. ventricosus - all show at least one primary spine for each plate). The wide space between the ambulacra is densely covered by pedicellaria, which are poisonous the a certain degree (some people become allergic to it).