The pubertal molt in Crustacea revisited

Summary

It is generally accepted dogma that sexual maturation in decapod crustaceans takes place after the “molt of puberty” to the adult form. However, in many instances, sexual maturation may take place before the “pubertal molt” resulting in the presence of polymorphic males with various mating strategies within a population. Male polymorphism is common in the spider crab Libinia emarginata, and the morphotypes differ with respect to body length and relative claw size. However, all reproductive individuals are recognized by the absence of the velvety epicuticle which covers the exoskeleton of recently molted individuals. The loss of the epicuticle is gradual, and during this time the reproductive system increases in size, methyl farnesoate increases in the hemolymph, and mating behavior is initiated. Male polymorphism, therefore, is evidence that the terminology “molt of puberty” is inappropriate and should be replaced with “differentiational” or “morphometric” molt.

Key words:

• Puberty molt
• maturation
• morphotypes
• crustaceans