AB 25:17-27 (2016)  -  DOI: https://doi.org/10.3354/ab00655

Geographic variability of Octopus insularis diet: from oceanic island to continental populations

Tatiana S. Leite1,*, Allan T. Batista2, Françoise D. Lima2, Jaciana C. Barbosa1, Jennifer Mather3

1Department of Oceanography and Limnology, Federal University of Rio Grande do Norte, Via Costeira, CEP 59014-100 Natal, RN, Brazil
2Ecology Pos-Graduation, Federal University of Rio Grande do Norte, Via Costeira, CEP 59014-100 Natal, RN, Brazil
3Psychology Department, University of Lethbridge, Lethbridge AB T1K 3M4, Canada
*Corresponding author:

ABSTRACT: A predator’s choice of prey can be affected by many factors. We evaluated various influences on population dietary composition, individual specialization and size of prey in Octopus insularis populations from 2 continental and 4 insular locations. We expected that habitat diversity would lead to diet heterogeneity. Furthermore, in keeping with MacArthur & Wilson’s (1967) theory of island biogeography, we expected that diet diversity would be lower around islands than on the coast of the mainland. Both predictions were confirmed when prey remains from octopus middens were examined. The 2 continental areas exhibited a richer habitat diversity and a wider variety of prey. Niche widths in the continental areas were 2.42 and 2.03, with the lowest niche widths exhibited by the population from the most distant oceanic islands (1.30, 0.85). We found variation in the proportion of specialist relative to generalist individuals across areas based on the proportional similarity index. The correlation between habitat diversity and niche width (R2 = 0.84) was highly significant, as was distance from the continental shelf and niche width (R2 = 0.89). This study reaffirms the central position of octopuses in the nearshore benthic ecosystem, and supports MacArthur & Wilson’s (1967) prediction of a lower diversity of species on islands—which applies not only to the species themselves, but also indirectly for the diet of their predators.


KEY WORDS: Octopus · Feeding niches · Diet · Population


Full text in pdf format  
Cite this article as: Leite TS, Batista AT, Lima FD, Barbosa JC, Mather J (2016) Geographic variability of Octopus insularis diet: from oceanic island to continental populations. Aquat Biol 25:17-27. https://doi.org/10.3354/ab00655

Export citation
Mail this link - Contents Mailing Lists - RSS
- -