ISSN:
1095-8649
Quelle:
Blackwell Publishing Journal Backfiles 1879-2005
Thema:
Biologie
Notizen:
The cyclic pattern of oocyte development in the sea bass, Dicentrarchus labrax L., was studied after induction of spawning by two injections, 24 h apart, of a luteinizing hormone releasing-hormone analog (LHRHa) administered at the end of vitellogenesis. The first difference in the developmental stage of the ovary and in the size-frequency distribution of oocytes between the LHRHa treated group and the control group, was detected 32 h after the first injection, the LHRHa group showing a higher proportion of the 900 μm diameter oocyte class (maturing oocytes) (P〈0.01). At 48 h LHRHa-treated females showed an increase in the 1000 and 1100 μm classes (maturing oocyte and ovulated eggs) (P〈0.01) and at 72 h these females exhibited a bimodal pattern, reaching the highest proportions in the 1100 (27.4%) and the 600 (14.7%) μm classes (ovulated eggs and advanced vitellogenic oocytes, respectively). Bimodal distributions were present in 80% of the LHRHa-treated females. Once oocyte final maturation was triggered by LHRHa the time needed for ovulation was about 48 h and the interval between consecutive ovulations and spawnings seemed to be 48–72 h.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1111/j.1095-8649.1992.tb02723.x
