MEPS 482:141-151 (2013)  -  doi:10.3354/meps10237

Effects of competition and egg predation on shelter use by Octopus tehuelchus females

Maite Narvarte1,2,*, Raúl Alberto González1,2, Lorena Storero1,2, Miriam Fernández3

1Consejo Nacional de Investigaciones Científicas y Técnica (CONICET), Av. Rivadavia 1917, C1033AAJ, Ciudad Autónoma de Buenos Aires, Argentina
2Instituto de Biología Marina y Pesquera Almirante Storni, Escuela Superior de Ciencias Marinas, Universidad Nacional del Comahue, Av. Güemes 1030, San Antonio Oeste 8520, Argentina
3Estación Costera de Investigaciones Marinas de Las Cruces, and Center for Advanced Studies in Ecology and Biodiversity, Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago, Chile

ABSTRACT: Parental care in the ocean ranges from provision to eggs and embryos to protection from predators. In particular, nest attendance has several benefits associated with relatively higher survival rates, lower vulnerability to predation and parasitism, and faster development rates. The quality of shelters matters, and adults of many species have to compete for suitable shelters. Here, we studied whether shelter type for brooding and egg protection from predation could be a determinant of competition among adults in the cephalopod Octopus tehuelchus. To this end, we (1) assessed the abundance of different types of shelters and preference under field and laboratory conditions, (2) tested the effect of intraspecific competition for shelters, (3) estimated density of potential sources of embryo mortality, and (4) determined the role of female protection in egg survival against predators. We found that in areas where shelters for development are scarce, females compete with males for the most suitable shelters. Fecundity depends on the female size, and shelters with higher volume are preferably selected by females. Excluding the brooding female from shelters resulted in increased egg mortality due to predation by octopus males and removal by chitons. We suggest that, in this species, shelter availability poses a constraint to brooding and affects total parental investment in reproduction and predation risk on eggs. This constraint may also take place in other marine invertebrates with similar life history traits, especially in areas where shelter is limited.


KEY WORDS: Shelter use · Competition · Predation on eggs · Octopus tehuelchus


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Cite this article as: Narvarte M, González RA, Storero L, Fernández M (2013) Effects of competition and egg predation on shelter use by Octopus tehuelchus females. Mar Ecol Prog Ser 482:141-151

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