Dr. Brante-Ramirez, Antonio

Marine gastropods show pronounced plasticity in shell morphology in response to local environmental risks such as predation and dislodgement by waves. Previous studies have focused on juvenile and adult snails; however, adaptive plasticity might be expected to begin during embryonic and early post-embryonic stages as a means of increasing survivorship when individuals first become vulnerable. We tested the above hypothesis by measuring shell morphology of encapsulated embryos and hatchlings of Acanthina monodon exposed to predator odor and water turbulence. Subjects were assigned to 1 of 4 treatments: (1) predator odor + high water turbulence, (2) no predator odor + high water turbulence, (3) predator odor + low water turbulence, (4) no predator odor + low water turbulence (control). After approximately 1 mo, morphological traits of the shell were measured using geometric morphometrics. Hatchlings, but not encapsulated offspring, produced larger shells in the predator treatments. Encapsulated offspring and hatchlings produced thicker shells in the predator treatments, irrespective of water turbulence, whereas thinner shells were produced when high water turbulence acted alone. Even before hatching, A. monodon can, thus, respond adaptively to potential mortality factors characterizing the local external environment. Anticipating risk in this way should enhance survivorship from the point of hatching through the vulnerable juvenile phase to adulthood.

Many Caribbean nations lack information on the ecology and biology of marine species, which are essential for food security and livelihoods in the region. This study aimed to advance the knowledge of two commercially important fish species, lane snapper (Lutjanus synagris) and white grunt (Haemulon plumierii), using cost-efficient techniques. Specifically, geometric morphometrics was used to assess the presence of ecomorphological groups (characterized by body shape variation associated with local environmental variables) in the Honduran Caribbean continental platform. Photographs of 104 lane snapper and 99 white grunt adult individuals were taken and digitalized with 12 landmarks. Subsequently body shape patterns were related to environmental variables using Distance-based linear models and Partial Least Squares. Results enabled the identification of ecomorphological groups or fish stocks in the study region associated with the environmental conditions of each site. Distance to river mouth and Chlorophyll a, both indicators of land-based stressors, appeared as the primary driving force of body shape differentiation in the species. These results are key for the development of informed reef fisheries management policies in the Caribbean region.