Aspects of evolution in the anomuran superfamily Paguroidea: one larval prospective

Summary

McLaughlin and Lemaitre (1997), in their examination of carcinization in the Anomura, rejected the traditional concept of paguroid evolution, which had consistently maintained that the lithodid crab-like body form evolved from a typical shell-dwelling hermit crab. Their hypothesis proposed just the reverse, i.e., the lithodid crab-like body form gave rise to the simple hermit crab body form through calcium loss, habitat change and consequential morphological adaptations. Their original hypothesis was based on characters derived from adult morphology, but they suggested that larval data would support their view. The megalopal and first or first- and second-crab stages of representatives of both subfamilies of the Lithodidae provide the first of such larval information. Ten species in eight genera have been examined specifically for development of abdominal tergites. These data, although preliminary in scope, unequivocally disprove the Bouvierian concept of lithodid abdominal plate development, and in so doing, lend substantial support to McLaughlin and Lemaitre's hypothesis.

Key words:

• Larval development
• carcinization
• abdominal evolution
• Anomura
• Paguroidea
• Lithodidae