Ecological Plasticity and Estuarine Specialization in Fontitrygon colarensis (Santos, Gomes & Charvet-Almeida, 2004): Implications for Habitat Connectivity Across the Amazonian Coastal Continuum

Fontitrygon colarensis is one of the least studied elasmobranchs of the Amazon estuarine region, with available knowledge remaining fragmented despite more than two decades since its formal description. This review synthesizes current information on the species' distribution, habitat use, reproductive biology, population structure, and conservation, while examining its ecological significance within the Amazonian coastal continuum. Available evidence indicates that F. colarensis is strongly associated with shallow estuarine habitats characterized by high environmental variability, muddy substrates, and extensive mangrove systems. Although fundamental aspects of its biology, including nursery habitat use, ontogenetic habitat shifts, movement ecology, and population connectivity, remain unknown, existing data suggest that the species exhibits a high degree of estuarine specialization combined with low reproductive output and a restricted geographic distribution. These characteristics may increase its vulnerability to habitat degradation and fisheries-related impacts. Interpreted within the framework of the Dynamic Environmental Reconfiguration Hypothesis (DERH), the ecological strategy of F. colarensis supports the view that habitat specialization can emerge through dependence on dynamic environmental transitions rather than isolated ecosystem boundaries. Consequently, conserving ecological connectivity across the Amazon estuarine continuum may represent a fundamental component of long-term conservation strategies for this endemic stingray. Future studies integrating telemetry, fisheries-independent surveys, environmental DNA, and population genetics are essential to clarify habitat connectivity, life-history patterns, and population dynamics in one of South America's most poorly understood batoids.