The present investigates the distribution of Acanthonyx lunulatus and Pilumnopeus
vauquelini in rocky bottom habitats in the Akkum region of Mersin (the
Mediterranean coast of Turkey). During the ecological survey, the female spiny crab
species (A. lunulatus) and the male bristle crab (P. vauquelini) were collected during
dives along the Erdemli-Akkum coast in July and August 2024. Samples were
obtained from the rocky area at a depth of approximately 3 m. The identification of
two species of crab was based on distinctive morphological features. The shell
lengths and widths of the two crab specimens were measured meticulously using
digital callipers. The details of both specimens were then recorded at the Mersin
University Museum of Marine Life, and catalogue numbers were allocated for both
species. Both crab species play essential roles in benthic ecosystems. A. lunulatus
inhabits rocky areas usually covered with algae, while P. vauquelini prefers
microhabitats such as under rocks and crevices. A. lunulatus has ecosystem
engineering roles such as increasing microhabitat diversity and providing shelter,
while P. vauquelini contributes to the sustainability of seafloor ecosystems by
consuming organic matter and mixing sediments. This study provides an essential
basis for assessing the long-term effects of human impact and invasive crab species
on Mediterranean ecosystems. Also, it presents important information for the
development of regional biodiversity management and conservation strategies.
Besides, long-term monitoring studies are needed to understand better the impact of
environmental factors on the distribution of these species.
Keywords: Crab, Acanthonyx lunulatus, Epialtidae, Pilumnopeus vauquelini,
Pilumnidae, Mersin Bay
