title: In- and outdoor reproduction of first generation common sole Solea solea under a natural photothermal regime: Temporal progression of sexual maturation assessed by monitoring plasma steroids and gonadotropin mRNA expression.
abstract: Reproduction of many temperate fishes is seasonal and maturation and spawning of gametes are under photothermal control. Reproductive success of first generation (G1) common sole Solea solea in captivity has been low. In this study, the sexual maturation status has been assessed during the prespawning months in G1 sole that were housed (a) outdoor under the natural photoperiod and temperature, or (b) indoor under artificial photothermal induction. Maturation was assessed in male and female G1 broodstock in November as controls, after which the remaining population was divided over two outdoor flow-through tanks placed in a pond and two indoor recirculating aquaculture system (RAS) tanks. Subsequently, maturation status (gonadosomatic index GSI and plasma levels of testosterone T and 17β-estradiol E2) was assessed in one tank for each condition in January, February and during spawning in early April, while fish in the other tank were not disturbed in achieving reproductive success. Quantitative real-time PCR was performed to determine species-specific gonadotropin mRNA expression in females. Successful G1 spawning and egg fertilisation occurred in all experimental tanks. Gonadal development was similar under both conditions. Higher E2 and T levels were found in indoor housed females. Gonadotropin expression revealed similar profiles between outdoor and indoor housed females. G1 sole could be reproduced in the outdoor tanks under the natural photoperiod and in the indoor tanks under artificial simulation of this regime that includes a potentially crucial chilling period of 2-3 months at 5-7 °C.
authors.affiliation: Institute for Marine Resources and Ecosystem Studies (IMARES), Wageningen Aquaculture, Wageningen University and Research Centre, Korringaweg 5, 4401 NT Yerseke, The Netherlands(1). Electronic address: arjan.palstra@wur.nl.
authors.forename: A P
authors.initials: AP
authors.lastname: Palstra
authors.affiliation: Institute for Marine Resources and Ecosystem Studies (IMARES), Wageningen Aquaculture, Wageningen University and Research Centre, Korringaweg 5, 4401 NT Yerseke, The Netherlands(1).
authors.forename: M C
authors.initials: MC
authors.lastname: Blok
authors.affiliation: Institute for Marine Resources and Ecosystem Studies (IMARES), Wageningen Aquaculture, Wageningen University and Research Centre, Korringaweg 5, 4401 NT Yerseke, The Netherlands(1).
authors.forename: J
authors.initials: J
authors.lastname: Kals
authors.affiliation: Institute for Marine Resources and Ecosystem Studies (IMARES), Wageningen Aquaculture, Wageningen University and Research Centre, Korringaweg 5, 4401 NT Yerseke, The Netherlands(1).
authors.forename: E
authors.initials: E
authors.lastname: Blom
authors.affiliation: NewCatch BV, J.H. Oortweg 19, 2333 CH Leiden, The Netherlands.
authors.forename: N
authors.initials: N
authors.lastname: Tuinhof-Koelma
authors.affiliation: NewCatch BV, J.H. Oortweg 19, 2333 CH Leiden, The Netherlands.
authors.forename: R P
authors.initials: RP
authors.lastname: Dirks
authors.affiliation: Cell Biology and Immunology Group, Wageningen University, De Elst 1, 6708 WD Wageningen, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Forlenza
authors.affiliation: Institute for Marine Resources and Ecosystem Studies (IMARES), Wageningen Aquaculture, Wageningen University and Research Centre, Korringaweg 5, 4401 NT Yerseke, The Netherlands(1).
authors.forename: R J W
authors.initials: RJ
authors.lastname: Blonk
mesh_terms: D000818:Animals; D017756:Aquaculture; D004958:Estradiol / Q000097:blood*; D005260:Female; D005412:Flatfishes / Q000502:physiology*; D006062:Gonadotropins / Q000235:genetics* / Q000378:metabolism; D006066:Gonads / Q000378:metabolism; D008297:Male; D017440:Photoperiod; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D012098:Reproduction / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012741:Sexual Maturation / Q000502:physiology*; D013696:Temperature; D013739:Testosterone / Q000097:blood*
chemical_list: D006062:Gonadotropins; D012333:RNA, Messenger; D013739:Testosterone; D004958:Estradiol
keywords: Aquaculture; First generation common sole/Dover sole Solea solea; Photothermal induction; Pituitary gonadotropin expression; Plasma steroids; Sexual maturation and reproduction