Reproduction in Reptiles

Abstract

Despite considerable diversity of reptilian cycles, it is possible to classify those of both males and females into a few broad categories. Most of the available information is derived from the Squamata and Chelonia, with little information available from the Crocodilia and Rhyncocephalia. The following patterns can be observed:

• 1. Seasonal breeding (discontinuous) with periods of reproductive activity separated by inactivity. Males show most variation in the time of onset and duration of spermatogenesis. Females may be seasonally monestrous (single clutch) or seasonally polyestrous (multiple clutch). This pattern is found in all temperate species and some from the tropics.

• 2. Acyclic (continuous) with a similar intensity of reproductive activity all year. Species with this pattern of reproduction tend to be tropical in distribution. There is some question as to whether truly continuous breeding in reptiles has been convincingly demonstrated in many species for which it is claimed. However, seasonal changes are much less dramatic than in temperate species, and at least one oviparous sea snake appears to have a continuous pattern of reproduction.