The Division of Coastal Sciences at the University of Southern Mississippi, within the School of Ocean Science and Engineering, is seeking a PhD student to join the Craboratory research group led by Dr. Zachary Darnell. The lab focuses on the behavioral and physiological ecology of marine invertebrates, with current research emphasizing seagrass ecosystems and nekton communities in and around the Gulf Islands National Seashore. Research topics include life history plasticity, behavioral mechanisms underlying migration, interactions between sexual and natural selection, and the effects of environmental variability and stressors on marine organisms. The Craboratory integrates field and laboratory experimental work with long-term observational data analysis to understand organismal function and environmental interactions. The group also addresses applied management and conservation questions from an organismal biology perspective. This PhD opportunity is ideal for students interested in marine biology, ecology, physiology, and conservation, particularly those passionate about seagrass ecosystems and coastal science. Applicants should have a strong background in biology, marine science, ecology, or a related field, and demonstrate research experience and communication skills. Application materials include a cover letter, CV, unofficial transcripts, and references, all in PDF format. The deadline for full consideration is February 1, 2026. For more information, visit the Craboratory website or contact Dr. Zachary Darnell directly. Keywords: Marine Biology, Seagrass Ecosystems, Nekton Communities, Coastal Sciences, Ecology, Physiology, Behavioral Ecology, Environmental Change, Organismal Biology, Conservation.