Larval development and allozyme variation in the East Atlantic Columbella (Gastropoda: Prosobranchia: Columbellidae)
Marco Oliverio

A survey on the neogastropod Columbella (Mollusca: Gastropoda: Prosobranchia) in the East Atlantic region was carried out. A morphological study of radular and protoconch (embryonic/larval shell) features, was conducted on populations from all over the distribution range. While radular morphology was rather uniform in all populations scored, protoconch examinations gave good indications on the variation in the larval ecology of the species studied. The Mediterranean C. rustica (Linné, 1758), with non-planktotrophic development, extends its range along the West African Atlantic coasts as far as Senegal. The Atlantic African populations South of Senegal all have a planktotrophic development. The latter are here considered conspecific with the Macaronesian populations, under the name C. adansoni Menke, 1853. Electrophoretic analysis was performed on one population from Canary Islands (with planktotrophic development) and two from the Mediterranean Sea (with non-planktotrophic development). The Macaronesian population proved to be genetically separated at species level from the Mediterranean ones. Further genetic examinations of population from the entire distribution range are needed, to support the taxonomy of this group.

Keywords: Neogastropoda, Columbella, speciation, East-Atlantic, Mediterranean, allozyme, SEM, radula, protoconch.
Contents of this volume Sci. Mar. 59(1) : 77-86 Back PDF
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