Behavioral Dynamics of Niche Partitioning between Two Octopus Species in a Shallow Coastal Environment


Meeting Abstract

P2-148  Friday, Jan. 6 15:30 – 17:30  Behavioral Dynamics of Niche Partitioning between Two Octopus Species in a Shallow Coastal Environment BENNICE, C.O.*; BROOKS, W.R.; RAYBURN, A.P.; HANLON, R.T.; Florida Atlantic University; Florida Atlantic University ; Marine Biological Laboratory cbennice@fau.edu

Identifying how species coexist is central to understanding community structure and biodiversity, and niche partitioning is one such mechanism. Species may use one or multiple mechanisms such as spatial partitioning, habitat partitioning, temporal partitioning, diet partitioning, or morphological partitioning. Two species of octopus (O. vulgaris and M.defilippi) inhabit a South Florida intracoastal waterway. The following aspects were examined: (1) spatial distribution of occupied dens, (2) influence of habitat heterogeneity for micro- and immediate habitat, (3) foraging behaviors, (4) foraging times and (5) diet. Octopus den locations were marked by GPS to quantify spatial patterns within and between species. The influence of habitat heterogeneity was determined by quantifying substrate composition for microhabitat (1.00 m2 around den) and immediate habitat (0.13 m2 directly over den). Video was used to score foraging behaviors and 24h-video determined octopus foraging cycles. Results demonstrate spatial overlap between the species. Micro- and immediate habitat are different between species; M.defilippi exploits open sand habitat mainly diurnally and uses flounder swimming mimicry to forage longer distances. O. vulgaris uses parachute attack and spends more time foraging on rock and rubble, mostly nocturnally. This study identifies ecological and behavioral components that facilitate coexistence of sympatric species, provides insight into cephalopod ecology and baseline conservation requirements for unique sand-dwelling organisms.

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