TY - JOUR
T1 - 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 experssion
AU - Palstra, A.P.
AU - Blok, M.C.
AU - Kals, J.
AU - Blom, E.
AU - Tuinhof-Koelma, N.
AU - Dirks, R.P.
AU - Forlenza, M.
AU - Blonk, R.J.W.
PY - 2015
Y1 - 2015
N2 - 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 17ß-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.
AB - 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 17ß-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.
KW - Aquaculture
KW - First generation common sole/Dover sole Solea solea
KW - Photothermal induction
KW - Pituitary gonadotropin expression
KW - Plasma steroids
KW - Sexual maturation and reproduction
U2 - 10.1016/j.ygcen.2014.12.004
DO - 10.1016/j.ygcen.2014.12.004
M3 - Article
SN - 0016-6480
VL - 221
SP - 183
EP - 192
JO - General and Comparative Endocrinology
JF - General and Comparative Endocrinology
ER -