Occurrence of Sphoeroides rosenblatti Bussing, 1996 (Teleostei: Tetraodontidae) along the coast of Guayas Province, Ecuador, and a comparison with sympatric Sphoeroides annulatus (Jenyns, 1842)

In summary, we report the occurrence of a new species of pufferfish, S. rosenblatti, for the continental coast of Ecuador, which appears closely related to, and occurs, sympatrically with, the common pufferfish species S. annulatus in mangrove forests. The two species differ morphologically (although the differences are subtle among juvenile fish), and variation in the most divergent trait that we measured, snout length, is generally associated with divergence in feeding in other groups, hinting at a potential mechanism for ecological segregation. We also found evidence of an inverse abundance pattern for these two species suggesting the potential for spatial segregation as well. More research is needed, however, on both these potential mechanisms of ecological segregation. Another direction for future research is the extent to which these species differ genetically, which would help shed light on their evolutionary history. Finally, more work is also needed to document the actual distribution of S. rosenblatti along the Pacific coast of South America.