Many sea anemones (Actiniaria) display agonistic behaviors towards genetically different conspecifics. When individuals come into tentacular contact, they engage in a series of agonistic behaviors, inflicting damage onto opponents with nematocyst-laden marginal structures termed “acrorhagi.” However, these behaviors remain poorly described in the majority of acrorhagi-bearing taxa. Here, I describe the agonistic behaviors of two Caribbean intertidal sea anemones: Bunodosoma granuliferum and Bunodosoma cavernatum. A unique posture and acrorhagial application behavior were documented for individuals of both species. A relatively low propensity to attack and retreat suggests that agonistic behavior may primarily serve a communicatory function in both Bunodosoma species considered in this study. Lastly, I also describe an onset of agonistic behavior induced by an environmental change. This study contributes to a comprehensive ethological understanding of agonistic repertoires across various acrorhagi-bearing Actiniarian taxa, elucidating the drivers of adaptive variation in these behaviors.