Enhancement projects within anadromous salmonid rivers of California have increased in recent years. Much of this work is intended as mitigation in regulated streams where salmon and steelhead spawning habitat is inaccessible or degraded due to dams, water diversions and channelization. Little research has been done to assess the benefits of spawning habitat enhancement to stream organisms othe...

The selection of spawning depth by Eurasian perch Perca fluviatilis was investigated in an experiment using artificial substrata in Lake Constance during the spawning season of 2007. The experiment compared spawning behaviour at substrata between 0.5 and 15 m depth at two sites exposed to different regimes of ship-generated wave action. The total abundance of egg ribbons did not differ signific...

The synthetic hormonal product Ovaprime was used for the induced spawning of Cyprinus carpio , in comparson with Pituitary gland extract. study done Basrah univ. Marine Sience Center freshwater fish hatchery. is an Analog Gonadotropine releasing hormone salmon (sGnRHa) as well Domperidone Dopamine Antagonist. first group C.carpio injected 0.5 ml one dose while second ( control) PG extract two 0...

this study aimed to investigate the spawning season, length at first maturity (lm 50 ) and sex ratio of metapenaeus affinis in the shrimp fishing grounds of hormozgan province, west of the persian gulf, iran. samples were taken by the swept area method and trawl net with 2 cm mesh size in the cod end from january 2010 to february 2011. results showed that the sex ratio deviated from 1:1 and fem...

Data on the abundance of spawning pink salmon (Oncorhynchus gorbuscha) are presented for rivers of southern Sakhalin Island and Iturup Island. Fluctuations in abundance are more dependent on marine survival than on the abundance of fry migrating downstream. This is explained by the favorable spawning conditions in small rivers with dense aggregations on the spawning grounds. We found stable lon...

Large offshore and small inshore populations of Atlantic cod Gadus morhua L. display differences in migratory patterns and settling regimes, but little is known about possible differences in spawning behaviour. Cod presumably of the Norwegian coastal cod type were therefore sampled during 7 spawning seasons (2002−2013) in Malangen, northern Norway. A spawning site in neighbouring Balsfjord was ...

The reproductive biology of albacore tuna, Thunnus alalunga, in the South Pacific Ocean was investigated with samples collected during broad-scale sampling between 2006 and 2011. Histology was done in a single laboratory according to standard protocols and the data analysed using generalized linear mixed-effects models. The sex ratio of albacore was female biased for fish smaller than approxima...

Environmental flows aim to mimic components of a river’s natural flow variability, including the magnitude, frequency, timing, duration, rate of change and the predictability of flow events. Aspects of the natural flow regime are thought to be linked to critical components of the life history strategies of many riverine fishes, including spawning and recruitment. In the Murray River, Australia,...

Spawning stock biomass (SSB) is one of the most common measures of stock status. However recent research on reproductive potential has shown that alternative variables may be an improvement over SSB. In the case of European hake (Merluccius merluccius), it is known that large individuals produce more eggs by unit of body weight, and their quality is better than those of small individuals. Under...