Female cheliped size underwent positive allometry throughout ontogeny, and the data indicate the existence of a single growth phase.
The major cheliped also exhibited positive allometry in both sexes, but during the second growth phase males attained larger claws than females.
Male cheliped length and pleopod length and female abdomen width experienced substantial shifts in growth rate during ontogeny.
Cheliped basis with large inner dorsodistal process.
Remarks: The secondary male differs substantially from the primary male, not just in respect of the typical characters of size and cheliped development, but also as regards the antennule structure, and pleopod setal number (higher in secondary male).
Because the relationship between the length of the dorsal propodus of the largest cheliped and the width of the carapace showed the greatest change over the size range of male crabs, that structure was chosen for allometric analysis to determine the size at which males become morphometrically mature.
Male crabs were designated as either morphometrically immature or mature by using differences in the regression equations for the relationships between the natural logarithms of the length of the dorsal propodus of their largest cheliped and carapace width in what were clearly either juvenile (small and gonadally immature) or adult crabs (large and gonadally mature).
During this period, the female typically groomed the egg mass with chelipeds
and walking legs as more and more eggs were extruded.
The abrupt growth acceleration in the male CH is directly associated with sexual maturation, because the cheliped
size is considered as a secondary sexual character (Mariappan et al.
thermydron megalopae lack distinctive family-specific characters such as the large sternal spines in some portunid megalopae or the recurved hooks found on the chelipeds
of some xanthids and cancrids (Martin et al.
Lobsters were outfitted with a numbered poultry tag (Nasco Farm and Ranch, Fort Atkinson, WI) on the right cheliped
between the carpopodite and meropodite segments for identification.