Reproductive biology of the holothurian Parastichopus regalis in the Mediterranean Sea and its implications for fisheries management

9 pages, 11 figures, 4 tables

The sea cucumber Parastichopus regalis is a fished resource in the northwestern Mediterranean Sea but there are no studies about its reproductive biology. The aim of the present study is to characterize the reproductive ecology of P. regalis including its sex ratio, a description of the gonad and the reproductive cycle to help the implementation of a sustainable exploitation plan. A total of 1728 specimens were dissected over two years (April 2012–March 2014). The sex ratio of P. regalis was 1♀:1.2♂. The occurrence of gonads showed seasonal patterns, progressively decreasing from April to August/September and increasing from November, with a peak in March. P. regalis had an annual reproductive cycle in the northwestern Mediterranean Sea, with gonad maturation during spring and spawning in summer. No gonads were found in autumn, thus the gonadal cycle started in winter. Gonadal tubules had a larger diameter in spring in females, but seasonal differences were not found in the tubule diameter for males. The maximum percentage of P. regalis specimens with gonad per 1 cm size class did not exceed 24%. These results characterize the reproduction of P. regalis filling a key information gap for future management of the commercial fishery, which is currently not regulated. As a fishery management strategy, we propose one closed season from April to June to protect the reproductive period. The influence of evisceration in the calculations of basic fishery parameters based on the presence or weight of the gonad (size at first maturity, gonadal index) further emphasizes the importance of this study

We also thank the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S). This work was supported by the Ministry of Science and Innovation of Spain (LLONGO project, reference AGL2011-25382)

Peer reviewed