Meeting Abstract
Sympatric species have evolved ecological, morphological, and behavioral specializations in combination with spatial and temporal distribution patterns to allow for coexistence. To explain species coexistence, how each species exploits its niche and any biotic interactions must be determined. Two species of octopus (Octopus vulgaris and Macrotritopus defilippi) with similar resource requirements overlap in an intracoastal habitat in southeastern Florida. The following aspects are examined for both species: (1) spatial distribution of octopus dens, (2) microhabitat heterogeneity, (3) foraging behaviors and (4) foraging times. Octopus den locations are marked by GPS to quantify spatial patterns within and between species. The importance of habitat heterogeneity is determined by quantifying substrate composition of the microhabitat (1.00 m 2 around den) and immediate habitat (0.13 m 2 directly over den). Video is used to score foraging behaviors and 24h video determines octopus activity time. Results have identified significant spatial clustering for O. vulgaris. Spatial patterns have not yet been determined for M. defilippi, but a non-random dispersal pattern is anticipated. Micro- and immediate habitat heterogeneity are important for both octopus species. Preliminary results indicate both species use similar foraging behaviors, but vary in their activity times; O. vulgaris forages primarily nocturnally while M. defilippi forages primarily diurnally. This study will identify ecological and behavioral components that facilitate coexistence of these sympatric species, provide insight into cephalopod ecology, and provide baseline conservation requirements for unique sand-dwelling organisms, which potentially use this habitat for mating and a nursery.
