Different developmental strategies in geminate mud snails, Cerithideopsis californica and C. pliculosa, across the Isthmus of Panama

Abstract

Larval developmental strategy is a key life-history trait governing many aspects of the ecology and evolution of marine invertebrates. We compared developmental strategies of two geminate, or sister, species of mud snails (Potamididae) on either side of the Isthmus of Panama, Cerithideopsis californica on the Pacific and C. pliculosa on the Atlantic coast. We found that these snails, separated by the rise of the Isthmus about 3 Ma, had different reproductive strategies. Larvae of C. californica hatched as small swimming veligers, whereas larvae of C. pliculosa hatched as large swimming–crawling veligers. Additionally, the larval duration of C. pliculosa was about 1 week shorter than that of C. californica under controlled laboratory conditions. This pattern of larval development is consistent with models of life-history evolution in which larger propagules are selected in low-productivity environments (in this case, the Atlantic) and smaller ones are favoured in highly productive environments (the Pacific).