*2.1. Study Site*

*Trapezia* spp. crabs were sampled from *Pocillopora* spp. colonies located in the Islas Marietas National Park (IMNP); a coral community located in the Central Mexican Pacific (CMP) region (Figure 1). This Natural Protected Area (NPA) harbors one of the most important coral communities of the Northeastern Tropical Pacific, one composed mainly of branching corals of the genus *Pocillopora* and massive and submassive corals of the genera *Porites* and *Pavona*. These three genera constitute most the hard coral cover [17] from 0 m to 20 m, as is typical elsewhere in the TEP [18]. The NPA is an oceanographic transition area where three oceanic currents converge: the Costa Rican Coastal Current, the California Current and the water mass of the Gulf of California [19]. The surface ocean temperature ranges from 23 to 30 ◦C during the year, with minimum and maximum values in March and September, respectively. Local conditions, such as upwelling and internal waves, cause the appearance of both daily fluctuations of up to 5 ◦C [20] and of a thermocline at depths of up to 20 m, resulting in highly variable conditions of sea temperature and dissolved oxygen [19,21,22]. This region is influenced by seasonal hurricanes, storms and natural stressors, and also by ENSO events that are associated with abnormal increases (El Niño) or decreases (La Niña) in surface temperature for several weeks or even months. Such temperature anomalies can affect the corals detrimentally, as can other environmental factors, such as altered pH and nutrient levels [23].
