background: active immunization against gnrh decreases the secretion of gonadotropins and causes cessation of gonadal function, thereby, inducing infertility. based on the immunoenhancing activity of kamdhenu ark (distilled cow urine), this study was performed to evaluate its effects on the gonadosomatic indices (gsi) and sperm parameters in male mice receiving a gnrh contraceptive vaccine. met...

Background: Gonadotropin releasing hormone conjugate (GnRH-BSA) raises antibodies against biologically active gonadotropin releasing hormone (GnRH) which affects body weight, gonadosomatic indices (GSI) and sperm quality in male mice. Objective: The objective of this experimental investigation is to develop an effective and reliable hormonal immunocontraceptive vaccine to suppress spermatogenes...

Fish reproductive biology plays an important role for fishery management, especially in developing countries. The aim of this study was to compile all available information and analyze reproduction patterns of marine fishes in three Large Marine Ecosystems (LMEs): North, East, and South Brazil Shelves. We tested the hypothesis that the onset and duration of spawning season differ among these th...

The cytochrome P450c17-I (CYP17-I) is one of the enzymes critical to gonadal development and the synthesis of androgens. Two single nucleotide polymorphisms (SNPs) were detected within the coding region of the CYP17-I gene in a population of 75 male Japanese flounder (Paralichthys olivaceus). They were SNP1 (c.C445T) located in exon2 and SNP2 (c.T980C (p.Phe307Leu)) located in exon5. Four physi...

The levels of testosterone (T) and 11-ketotestosterone (11-KT) of the South American pacu Piaractus mesopotamicus were determined by radioimmunoassay during two stages of the reproductive cycle, i.e., resting and maturation, and the gonadosomatic index (GSI) was calculated. The highest levels of T and 11-KT were reached during the maturation stage (T = 2400 +/- 56 pg/ml; 11-KT = 2300 +/- 60 pg/...

BACKGROUND Rasbora tawarensis is an endemic freshwater fish in Lake Laut Tawar, Aceh Province, Indonesia. Unfortunately, its status is regarded as critical endangered with populations decreasing in recent years. To date no information on the spawning activities of the fish are available. Therefore, this study provides a contribution to the knowledge on reproductive biology of R. tawarensis espe...

background: gonadotropin releasing hormone conjugate (gnrh-bsa) raises antibodies against biologically active gonadotropin releasing hormone (gnrh) which affects body weight, gonadosomatic indices (gsi) and sperm quality in male mice. objective: the objective of this experimental investigation is to develop an effective and reliable hormonal immunocontraceptive vaccine to suppress spermatogenes...

Sablefish (Anoplopoma fimbria) is a marine groundfish that supports valuable fisheries in the North Pacific Ocean and holds promise for marine aquaculture. Limited information is available, however, about its reproductive biology. This study aimed to characterize the complete reproductive cycle, including seasonal changes in gonadal development (macroscopic and histological), plasma sex steroid...

This study analyzed the reproduction and growth of freshwater prawn, Palaemon paucidens De Haan 1844 from Suk-dang lake(Korea). The analysis of the sex ratio showed a higher proportion of males than that of females. The average size of the eggs was 6.12 (+/-0.55) mm3 in the non-eyed stage (stageA) and 7.20 (+/-0.86)mm3 in the eyed stage (stage B). The reproductive output (RO) calculated with th...