Spatial Analysis of Octopus Dens and Predation

Date of Award

2010

Document Type

Thesis

Degree Name

Bachelors

Department

Natural Sciences

First Advisor

Gilchrist, Sandra

Keywords

Octopus, Predator Prey Interactions, Mathematical Modeling

Area of Concentration

Marine Biology

Abstract

Octopuses build dens based on a variety of factors, possibly including the location of predators, prey, and available den materials. Through field work and computer modeling, this thesis examines these factors and their effect on den location and the local prey population. Field work was conducted in Cayos Cochinos, Honduras and studied the location of 10 octopus dens, eels as major predators, and two bivalve species as prey. Major prey items were determined based on midden contents and measurements of distances and angles were used to create a map of the locations of predators, prey, and octopus dens. A computer model was created to simulate the dynamics of the system. The model allowed for movement of octopuses among a matrix including the occupying of dens and consuming of prey. Initial conditions such as octopus concentration, prey concentration, and available den concentration were explored with changes in search radii and variations in spatial arrangements of prey and available dens. Through both field work and simulations, octopuses were found to choose dens on borders between areas of prey (such as a sea grass bed) and areas of available dens (coral reef).

Rights

This bibliographic record is available under the Creative Commons CC0 public domain dedication. The New College of Florida, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.

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