Echinolittorina omanensis, Published, 2007

Reid, David G., 2007, The genus Echinolittorina Habe, 1956 (Gastropoda: Littorinidae) in the Indo-West Pacific Ocean, Zootaxa 1420 (1), pp. 1-161 : 31

The Echinolittorina natalensis group

This group consists of E. natalensis , E. omanensis n.sp. and E. subnodosa from the western Indian Ocean, Arabia and Red Sea respectively, and a fourth species E. pascua from the distant locality of the southeastern extremity of Polynesia. All share similar nodulose shells, resembling those of the E. malaccana group with which, however, they are never sympatric. The most notable difference in the shells of the two groups is that those of the E. natalensis group (except E. omanensis ) are slightly broader and (except E. pascua ) usually bear three rows of nodules on the final whorl; shells of the E. malaccana group are usually more tall-spired and almost always bear only two rows of nodules. Anatomically, the E. natalensis group shares a tapering, wrinkled penial filament, short paraspermatozoan rod-pieces, and a single long bursa opening at about one third to half of the length of the straight section of the pallial oviduct; these characters are distinct from those of the E. malaccana group. Sequences of two mitochondrial genes support the monophyly of these four species (Williams & Reid 2004).