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Helgol Mar Res (2011) 65:4349 DOI 10.1007/s10152-010-0199-y
ORIGINAL ARTICLE
Spawning strategy in Atlantic bobtail squid Sepiola atlantica (Cephalopoda: Sepiolidae)
Marcelo Rodrigues Manuel E. Garc Jess S. Troncoso ngel Guerra
Received: 20 November 2009 / Revised: 18 March 2010 / Accepted: 19 March 2010 / Published online: 6 April 2010 Springer-Verlag and AWI 2010
Abstract This study aimed to determine the spawning strategy in the Atlantic bobtail squid Sepiola atlantica, in order to add new information to the knowledge of its reproductive strategy. A total of 12 females that spawned in aquaria were examined. Characteristics of the reproductive traits and egg clutches were similar to those of other known Sepiolidae. Clutch size varied from 31 up to 115 eggs. Females of this species had incorporated up to 1.58 times of their body weight into laid eggs. The size of laid eggs showed a positive correlation with maternal body size, supporting the idea that female size is a determinant of egg size. Our data suggest that S. atlantica is an intermittent terminal spawner, and that its spawning strategy comprises group-synchronous ovary maturation, multiple egg laying, and deposition of egg clutches in diVerent locations. The obtained data provide insights for future comparative studies on reproductive allocation.
Keywords Spawning strategy Egg size Reproduction
Sepiola atlantica
Introduction
Cephalopods have highly variable and complex life history traits related to reproduction (Hanlon and Messenger 1996). Information on reproductive strategies may lead to a better understanding of the evolution of life histories, both reproductive strategies and life cycles being genetic adaptations to optimize the use of ecological niches in direct competition with other species and in response to environmental conditions (Rocha et al. 2001). The patterns of ovulation and spawning are basic elements to characterize cephalopod reproductive patterns.
Ovulation patterns may be distinguished according to oocyte formation and development and are strongly correlated with spawning patterns (see Rocha et al. 2001; Nigmatullin 2002). Among the spawning patterns deWned by Rocha et al. (2001) are multiple spawning and intermittent terminal spawning. According to these authors, spawning in the former pattern is monocyclic and eggs are laid in separate batches, with somatic growth continuing between separate events. The intermittent terminal spawning diVers from multiple spawning in that somatic growth does not take place between spawning...