|Distribution||Recent; tropical Indo-Pacific.|
|Type||Echinostrephus aciculatus A. Agassiz, 1863, by original designation.|
|Classification and/or Status||Camarodonta; Echinoida; Echinometridae.
|Remarks||The high ambitus makes this genus instantly identifiable. It lives in reefal environments where it bores a living chamber for itself. It uses its aboral spines for defence and its aboral tube-feet to capture drift algae. Larger individuals may become trapped within their hole as they grow.
Although the two species differ in the number of pore-pairs incorporated into a compound plate (E. aciculatus has four, E. molaris three), they are similar in other respects and thus treated as congeneric.
Agassiz, A. 1863. List of echinoderms sent to different institutions in exchange for other specimens. Bulletin of the Museum of Comparative Zoology, Harvard College, 1 (2), 17-28.