摘要：The thick-shelled clam Meretrix morphina (Lamarck, 1818) has previously been reported erroneously asMeretrix meretrix (Linnaeus, 1758) in the western Indian Ocean 1,2 because of an invalid synonymy which has onlyrecently been rectified 3 . The species is restricted to the shores of the west Indian Ocean, but has occasionally beenreported from South African coastal waters, mainly as dead shells. 1 Branch et al. 2 and Kilburn and Rippey 4 havestated that M. morphina does not occur naturally south of Maputo Bay, Mozambique; however, this species hasrecently been recorded in the St Lucia and Mlalazi estuaries. This occurrence represents another case of polewardrange expansion, probably in response to global warming, as many such cases have already been documentedalong the South African coastline. 5 The mode of introduction into Lake St Lucia remains unresolved, but possiblemeans involve either transport of veligers from Maputo Bay via the southward flowing Agulhas Current or human-mediated introduction of adults as bait for recreational fishing.
