Meeting Abstract
Sympatric species have evolved ecological, morphological, and behavioral specializations in combination with spatial and temporal distribution to allow for coexistence. To determine how two species coexist, it must first be determined how each species exploits its niche and any occurrence of biotic interactions (intra- and interspecific competition). Two species of octopus (Macrotritopus defilippi and Octopus vulgaris) with similar resource requirements overlap in an intracoastal habitat. This study assessed (1) spatial distribution of octopus home or “den” space and (2) potential importance of microhabitat heterogeneity. Octopus den location is marked by GPS to quantify spatial patterns of both species and their spatial relationship to each other. The importance of habitat heterogeneity is measured by determining substrate make-up of the microhabitat and immediate den space for both species. Direct observations and underwater photoquadrats of microhabitat substrate make-up are analyzed in CPCe software to determine frequencies of substrate make-up. Results have identified spatial clustering of O. vulgaris. No spatial pattern has been identified for M. defilippi . Significance for substrate make-up of microhabitat and immediate den space has also been reported for both species. This study identifies ecological and behavioral components that facilitate coexistence of sympatric species, provide insight into cephalopod ecology, and provide baseline conservation requirements for these unique sand-dwelling organisms. This site may serve use as a mating and nursery habitat.
