SPECIATION IN SPINY-LOBSTERS - CLUES TO CLIMATICALLY-INDUCED CHANGES IN OCEAN CIRCULATION PATTERNS

Allopatric speciation in spiny lobsters is accelerated during periods when long-lived teleplanic phyllosoma larvae are retained within more distinctly separated ocean surface circulatory systems. The example is given of a widely-distributed Indo-Pacific spiny lobster Panulirus ho marus which occurs in three distinct parts of the Indian Ocean, as thr ee readily distinguishable varieties or subspecies. A degree of hybrid ization is evident where subspecies overlap. Inferred surface circulat ion patterns during Pleistocene glacial periods suggest that more comp lete separation of larval ''pools'' due to changed circulation systems caused by altered wind patterns and intensities, together with shoali ng ridges and rises (associated with lowered sea level) may have promo ted the emergence of these new subspecies.