The marine medaka, Oryzias dancena is a suitable sample as a laboratory animal because it has a small size and clearly distinguishes between female and male. Data on the growth and maturity of the diploid and triploid sea cucurbit species suitable for laboratory animals are very useful for studying other species. Triploidy was induced in the marine medaka by cold shock treatment (0°C) of fertil...

Determining when fish spawn has major implications for effective fisheries management, particularly in dam-controlled rivers where reproductive potential may be affected by an altered hydrograph. Three methods for estimating spawn timing in riverine broadcast spawners were compared for their precision, effort and potential impact on a population of Mountain Whitefish in the regulated Lower Dunc...

............................................................................................................................... i Acknowledgments.............................................................................................................. iv List of Tables ..................................................................................................................... ix Li...

This study characterizes the seasonal reproductive cycle of male round stingrays (Urobatis halleri) in Seal Beach, California. Mature round stingrays were collected monthly by beach seine near the San Gabriel River outfall from August 2004-September 2006, and rays were assessed for gametogenesis and steroid hormone levels. Male round stingrays exhibit a seasonal pattern of increased gonadosomat...

12 Two large groups of fingerling (3.2g) male European sea bass (around 75,000 13 individuals each) reared in net sea cages for a period of two years were exposed to two 14 different photoperiods starting in June: either ambient photoperiod (37o 24 ́ N) (NP) or a 15 constant long photoperiod (LP; 18 hours light: 6 hours dark, 18L: 6D). Long days had limited 16 effect on somatic growth at the tim...

In order to determine the reproductive characteristics of Liza parsia, a fish of commercial importance, the GSI, egg diameter, sex ratio and fecundity were examined in 331 specimens caught monthly for a period of ten months from September 2006 to June 2007. According to the GSI and egg diameter, the reproduction period of Liza parsia was determined to be in November to March with two peaks in t...

Formaldehyde (FA) is the leading cause of cellular injury and oxidative damage in testis that is one of the main infertility causes. There has been an increasing evidence of herbal remedies use in male infertility treatment. This assay examines the role of Ficus carica (Fc) leaf extracts in sperm parameters and testis of mice intoxicated with FA. Twenty-five adult male mice were randomly divide...

Effects of daily administration of melatonin for 15 days were evaluated with respect to ovarian activities and plasma gonadotropin (GtH II) and vitellogenin (Vg) levels in intact (INT) and pinealectomized (Px) female catfish, C. batrachus, during preparatory (April), prespawning (May and June), spawning (July) and post-spawning (September) periods. Px (saline control groups) caused a stimulator...

The accumulation of cadmium, copper and zinc and the induction of metallothioneins (MT) in liver of three freshwater fish species was studied. Gudgeon (Gobio gobio), roach (Rutilus rutilus) and perch (Perca fluviatilis) were captured at 6 sampling sites along a cadmium and zinc gradient and one reference site in a tributary of the Scheldt River in Flanders (Belgium). At each site up to 10 indiv...