Reproductive biology of the sand dollar, Peronella lesueuri (L. Agassiz, 1841) (Echinoidea: Clypeasteroida: Laganidae), in south-western Australia

Abstract

The reproductive biology of the sand dollar Peronella lesueuri was studied between 2009 and 2011 in Cockburn Sound, a large coastal embayment in south-western Australia. Individuals of P. lesueuri did not display sexual size-dimorphism, and the population was found to have a sex ratio of 1:1. Maturity occurred over the range of 80–115 mm with all sand dollars larger than 115 mm having distinct gonads. Monthly histological analysis of gonads and changes in oocyte proportions over time indicated that P. lesueuri has an annual reproductive cycle; gametogenesis occurs in spring and spawning in summer. Differences in the rate of gametogenesis between 2009/2010 and 2010/2011 may have been influenced by higher temperatures experienced in 2010/2011. P. lesueuri have large ova (mean = 210 μm), which suggests the species has lecithotrophic larval development.

Keywords:

• sand dollar
• gametogenesis
• reproductive cycle
• lecithotrophic
• maturity
• Peronella

Acknowledgements

We thank CSIRO researchers, Ryan Crossing and Dr Douglas Bearham for helping with the dredging and data collection and also the boat skipper Stelios Kondylas. Special thanks also to Gordon Thomson for his invaluable help with the histological component of this study. This study was made possible by the Murdoch University Research Scholarship and a PhD top-up scholarship and project funding from the Western Australia Marine Science Institution (WAMSI). We thank the anonymous reviewers for valuable comments on the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Western Australia Marine Science Institution (WAMSI).