Abstract Brachyuran crabs of the genus Mithraculus White, 1847 are primary consumers that represent important reservoirs of biomass and energy in the Caribbean Sea ecosystem. We provide a study of the occurrence and size distribution M. sculptus (Lamarck 1818) and M. corype (Herbst, 1801), found in coastal lagoons of the southern Mexican Caribbean. A total of 329 individuals were found in the sampled area, with higher abundance during the rainy season. The Mahahual sampling site showed the highest abundance, coinciding with a seabed covered by coral rubble and sand with seagrass. The lagoons of the southern Mexican Caribbean supported the presence of M. corype and M. sculptus, likely driven by coral degradation and the ecological succession of reef substrate towards seagrass, algae, and coral-rubble bottoms. These results highlight the importance of Mithraculus species as indicators of increasing abundance of primary producers such as algae and seagrass. This pattern may be linked to the loss of coral in the Mexican Caribbean, which has facilitated the establishment of these primary producers and the subsequent restructuring of trophic chains.
Rosas‐Luis et al. (Wed,) studied this question.