Fecundity pattern and spawning dynamics of the common cuttlefish Sepia officinalis

ABSTRACT

The fecundity pattern of common cuttlefish, Sepia officinalis, was assessed in Thermaikos Gulf, one of the species’ main fishing grounds in the eastern Mediterranean. Female samples, collected with coastal fishing gears during the population spawning season (January–July), were analysed using a combination of histology and whole mount analysis of ovarian tissue. The potential fecundity was shown to vary seasonally, showing the highest values at the beginning of spawning, gradually dropping thereafter. Previtellogenic oocytes (<0.5 mm) were the most prevalent group occurring throughout the spawning period in all maturity stages. Low or null levels of oocyte recruitment during the spawning period in combination with seasonal drop in fecundity and clutch-specific egg production suggest that the fecundity pattern of cuttlefish displays similarities with the so-called ‘determinate fecundity’ pattern of fishes. Spent females end up having small reserves of secondary growth oocytes (pre- and vitellogenic) that will never be spawned. Potential annual fecundity was thus estimated as the difference in total fecundity between pre-spawners and spent females and equalled 2569 oocytes/eggs. For a spawning period of four months, the ratio between potential fecundity and clutch size (100–200 eggs) indicated 13–25 different spawning events with a mean interval of 5–9 days.

KEYWORDS:

• Common cuttlefish
• Sepia officinalis
• potential fecundity
• intermittent spawning
• reproductive potential

Acknowledgements

The present work was performed within the framework of EcoSEPIA project (http://eco-sepia.bio.auth.gr/). The authors are grateful to Rozalia Perri, G. Christidis, C. Antoniadou, X. Simeonidou, K. Georgiadis, A. Plepel and E. Voultsiadou for their help during samplings and work in the lab. Special thanks are due to the captain of the chartered vessel F. Karydas for sharing his knowledge and his insights during all stages of this work. EcoSEPIA was supported by the Greek Operational Programme for Fisheries and Sea (2014–2020), under the ‘Innovation for Fisheries’ call [MIS 5010349].

Disclosure statement

No potential conflict of interest was reported by the author(s).

Ethics approval

Samplings and animal processing were performed with the permission of the Fisheries Department, Directorate of Agricultural Economy and Fisheries, of the Region of Central Macedonia.

Data/Code availability

Data will be made available on reasonable request.

Authors’ contribution

The paper was conceived by K.G.; I.F.K. participated in the fieldwork, conducted the biometric measurements, prepared the histological sections and did whole-mount analyses. Statistical analysis and figure preparation were performed by K.G. and I.F.K. The manuscript was written by K.G. with additional input from I.F.K.

Additional information

Funding

The present work was funded by the Greek Operational Programme for Fisheries and Sea (2014–2020), under the ‘Innovation for Fisheries’ call [MIS 5010349].