Abstract
Successful spontaneous reproduction and the production of viable offspring of wild fish in captivity can take some years of adaptation, and may also involve different environmental conditions, sex ratios and densities compared to natural populations. We followed the reproductive cycle of wreckfish Polyprion americanus—a late maturing, deep-sea benthic species—in captivity in three different broodstocks in Spain under natural photoperiod and temperature, and one broodstock in Greece under a constant temperature of 16 °C for two consecutive years, to describe the reproductive cycle of the species and the associated sex steroid hormone profiles. Oogenesis begun in the fall and post-vitellogenic oocytes of 1250 μm were present between March and June. Males were in spermiation condition and produced good-quality sperm throughout the year, regardless of the temperature profile to which they were exposed. Some females completed oogenesis, underwent oocyte maturation, and spawned spontaneously under both constant and fluctuating temperatures. The sex steroid hormones of both males and females followed the already-known profiles during fish gametogenesis, except for 17,20β-dihydroxy-progesterone, which did not seem to be related to either female or male maturation. The female reproductive dysfunctions that were identified included (a) the arrest of oogenesis at the cortical alveoli stage in certain females; (b) the failure to undergo oocyte maturation in others; and (c) the production of large percentages of unfertilized eggs from the females that spawned spontaneously. Our study suggests that reproduction in captivity is possible in wreckfish maintained under typical marine aquaculture conditions, but that reliable spawning and production of high-quality eggs may require some years of adaptation to captivity, before the reproductive dysfunctions will be overcome.
Highlights
The wreckfish Polyprion americanus is a globally distributed fish inhabiting continental coasts and oceanic islands at depths of 100–1000 m [1,2]
The asynchronous nature of oogenesis was apparent in the December biopsies, with a large size variation of vitellogenic oocytes, ranging in diameter from 600
The asynchronous nature of oogenesis was apparent in the December biopsies, with a large size variation of vitellogenic oocytes, ranging in to 900 μmfrom
Summary
The wreckfish Polyprion americanus is a globally distributed fish inhabiting continental coasts and oceanic islands at depths of 100–1000 m [1,2]. Its rapid growth even at relatively low temperatures, its late maturation and good adaptation to captivity [1,5], together with its limited landings from the capture fisheries, high flesh quality and market value make the wreckfish an excellent candidate for the diversification of aquaculture production. Attempts have been made to control its reproduction and produce viable eggs, spawning has been inconsistent, and the produced eggs often exhibit low fertilization [9]. There is a need for a more detailed study of the reproductive function of this species in captivity, before its maturation and spawning can be reliably controlled for the purposes of aquaculture
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
