Alpheus strenuus is an Indo-West Pacific and Indian Ocean snapping shrimp that belongs to the Edwardsii species group within the genus Alpheus. Banner and Banner (1982) separated Alpheus strenuus into A. strenuus strenuus and A. strenuus cremnus on the basis of a few morphological differences, and also suggest that ecological differences may separate the subspecies, with A. s. strenuus on coral reefs and islands (in clean sand and cleaner waters) and A. s. cremnus more common in muddy and estuarine environments. Banner and Banner (1983) collected A. strenuus strenuus from the Seychelles from large burrows/tubes between large granite boulders on windswept shores; tubes were constructed of dense coralline algae and terminated in a large chamber under a boulder. A. strenuus strenuus shared these tubes with fireworms in the genus Eurythoe, and occasionally brittle stars; associations with fireworms have also been noted from Enewetak and Australia. In the same locality they also occurred under boulders in sandy areas (the same habitat association has been noted in Pacific specimens of A. s. strenuus).For more details, see ABRS (2009): http://www.environment.gov.au/biodiversity/abrs/online-resources/fauna/a....