Reproductive-plasticity
Guides
Arenaeus cribrarius
Speckled Swimming Crab
Arenaeus cribrarius, the speckled swimming crab, is a portunid crab distributed throughout the western Atlantic from Massachusetts to Argentina. It inhabits shallow sandy substrates but occurs to depths of 61 m, burying itself in sediment while maintaining respiratory water flow through a maintained gap. The species exhibits nocturnal, solitary behavior and is an opportunistic feeder that ambushes prey from its buried position. It supports commercial fisheries, particularly along the Brazilian coast, and has demonstrated reproductive plasticity in response to population pressures.
Platythyrea punctata
Common Silvery Hunter Ant
Platythyrea punctata is a neotropical ant species distinguished by its remarkable reproductive flexibility. Most populations reproduce through thelytokous parthenogenesis, where unmated workers produce female offspring from unfertilized eggs, resulting in colonies with clonal genetic structure. The species also exhibits facultative sexual reproduction, with occasional queens, gamergates (mated reproductive workers), and males appearing in some populations. This combination of alternative reproductive tactics is unique among ants and has made the species a model for studying social evolution, division of labor, and the transition between sexual and asexual reproduction.