Annual change in reproductive condition and plasma concentrations of sex steroids in black bream, Acanthopagrus butcheri (Munro) (Sparidae)

Abstract

Changes in gonadosomatic index (GSI), hepatosomatic index (HSI), gonad stage and plasma concentrations of sex steroids were studied over one year in black bream (Acanthopagrus butcheri). Black bream have an annual reproductive cycle with a 3-month spawning season in spring–early summer. GSI and HSI values were highest in October and May respectively. Plasma concentrations of oestradiol-17β (E2), testosterone (T) and 17,20β-dihydroxy-4-pregnen-3-one (17,20βP) were highest in females in October. Plasma concentrations of E2 and T were highest in ovulated fish. Concentrations of 17,20βP were higher in fish undergoing final oocyte maturation (FOM) than in fish with regressed gonads. In males, plasma concentrations of T and 11-ketotestosterone (11KT) increased in September and remained elevated until January, but concentrations of 17,20βP did not change with season. However, 17,20βP concentrations in spermiated fish were higher than in non-spermiated fish. Daily changes in gonad condition indicated that females undergo daily cycles of ovarian maturation with ovulation occurring after midday. Plasma T and 17,20βP concentrations of females were elevated at midday in association with FOM, but E2 showed no diel change. In males, partially spermiated fish were dominant in the early morning and fully spermiated fish at midday. Plasma T, 11KT and 17,20βP concentrations were low at midnight and reached maximum levels at 0600 hours.

Mating behaviour and gamete release in gilthead seabream (Sparus aurata, Linnaeus 1758) held in captivity

“…In the present study, the spawning activity took place midmorning, which was actually initiated 42 ± 8 min after the lights switched on and can be considered similar to previous studies that established that gilthead seabream and others sparid fish such as silver seabream (Sparus sarba), Pacific seabream (Acanthopagrus pacificus), yellowfin bream (Acanthopagrus australis), red seabream (Pagrus major) and black bream (Acanthopagrus butcheri) tend to spawn at sunset or early in the morning (Pollock, 1982;Matsuyama et al, 1988;Mihelakakis & Kitajima, 1995;Haddy & Pankhurst, 1998;Meseguer et al, 2008;Sheaves & Molony, 2013). In the present study, spawning was successfully and regularly obtained and presented a prolonged spawning season (up to 5 months).…”

Effect of gonadotropin releasing‐hormone analogue and human chorionic gonadotropin on milt characteristics and gonadal steroids in yellowfin bream,Acanthopagrus australis(Sparidae)

“…In the current study, captive yellowfin bream were naturally sperimating, but plasma levels of 11-KT and T were low in comparison with values reported for other species (e.g., Carragher & Pankhurst 1993;Haddy & Pankhurst 1998). However, the number of males with plasma 11-KT levels above the assay detection limit increased coincident with increasing maturity.…”

“…However, the number of males with plasma 11-KT levels above the assay detection limit increased coincident with increasing maturity. In wild black bream (A. butcheri), plasma levels of 11-KT and T are elevated throughout the spawning season and plasma levels of 17,20βP are highest in spermiated fish (Haddy & Pankhurst 1998). The timing of this study (early in the spawning season) may explain the low levels of T and 11-KT in naturally sperimating yellowfin bream, as in both A. butcheri (Haddy & Pankhurst 1998) and Pagrus auratus (Carragher & Pankhurst 1993), plasma androgen levels increase with advancing maturity.…”

Social modulation of androgen levels in male teleost fish

“…First, in some species with which we are . Numbers refer to the following species: 1, Acipenser ruthenus (Mojazi Amiri et al, 1996); 2, Oncorhynchus mykiss (Rouger and Liley, 1993); 3, Oncorhynchus nerka (Kubokawa et al, 1999); 4, Salmo salar (Mayer et al, 1990b); 5, Salmo trutta (Cardwell et al, 1996); 6, Salvelinus fontinalis (Cardwell et al, 1996); 7, Cyprinus carpio (Nikitina and Godovich, 1984); 8, Catostomus commersoni (Scott et al, 1984); 9, Ictalurus nebulosus (Rosenblum et al, 1987); 10, Heteropneustes fossilis (Lamba et al, 1983); 11, Fundulus heteroclitus (Cochran, 1987); 12, Porychthys notatus (Knapp et al, 1999); 13, Gasterosteus aculeatus (Mayer et al, 1990a); 14, Syngnathus acus (Mayer et al, 1993); 15, Syngnathus typhle (Mayer et al, 1993); 16, Lates calcarifer (Guiguen et al, 1993); 17, Dicentrarchus labrax (Prat et al, 1990); 18, Morone saxatilis (Mylonas et al, 1997); 19, Lepomis macrochirus (Kindler et al 1989); 20, Stizostedion vitreum (Malison et al, 1994); 21, Pomatomus saltator (MacGregor et al, 1981); 22, Pagrus major (Ouchi et al, 1988); 23, Acanthopagrus butcheri (Haddy and Pankhurst, 1998); 24, Rhabdosargus sarba (Yeung and Chan, 1987); 25, Sparidentex hasta (Lone et al, 1991); 26, Cynoscion nebulosus (Thomas et al, 1982); 27, Oreochromis aureus (Mol et al, 1994); 28, Oreochromis mossambicus ; 29, Sarotherodon melanotheron ; 30, Chromis dispilus (Pankhurst, 1990); 31, Acanthochromis polyacanthus (Haddy and Pankhurst, 1998); 32, Hypsypops rubicundus (Sikkel, 1993); 33, Sparisoma viridae (Cardwell and Liley, 1991); 34, Parablennius sanguinolentus parvicornis …”