Gilan Attaran-Fariman

• Biodiversity Journal, 7 (4): 935-944 - MONOGRAPH

  Yaser Fatemi, Gilan Attaran-Fariman & Paolo Stara
  Sculpsitechinus iraniensis n. sp. (Clypeasteroida Astriclypeidae), from Chabahar Bay, southeast coast of Iran

  ABSTRACT
  In the past, the practice of giving more weight to the outer shape of echinoderms than the structural characters, has led to misinterpretations in the systematics within the family Astriclypeidae Stefanini, 1912 (Clypeasteroida). We do not know, often, what the previous researchers were referring to when they refer to Echinodiscus, since many of these, in fact, belong to the genus Sculpsitechinus (at present including two species: S. auritus and S. tenuissimus). Every sand dollar that had two posterior ambulacral slots opens on the rear edge, was always classified as “E. auritus” now accepted as S. auritus. In fact, this general form, common across the Indian Ocean and spread to Indonesian Archipelago, until the Western Pacific, shows, locally, strong differences that justify a change in the specific allocation. A new form of living Sculpsitechinus was found from the sediments at low tide of Chabahar Bay, located along the Iranian coast of the Gulf of Oman. The analysis of morphometric and structural data, allowed us to establish this form as a new species: S. iraniensis n. sp. This new species differs from the type species of S. auritus mainly by the considerable size of the petalodium, that reaches the mean of 55% of test length, in comparison to the mean of 40% of the type test length. Moreover, the studied population shows considerable variability in the plating scheme of the adoral face, which will give rise to future insights.

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