Saginaw Bay is a large embayment on the western (Michigan) side of Lake Huron that historically supported a productive commercial walleye fishery that has more recently become an outstanding recreational fishery Michigan DNR, Ohio DNR, and Michigan State University teamed up to determine the spawning
stocks that supported this valuable fishery* Genetic analysis revealed that approximately 26 percent of Saginaw Bay walleyes spawned in Lake Erie and Lake St.
Some of the fishes were found with developing ovaries during the months of October and November, while the rest were in the spawning
and spent stages.
Andara granosa, reproductive cycle, shell microgrowth increment, growth pattern, spawning
the number of progeny that will survive each year to be incorporated into the population) depends (in most traditional fishery assessment models) directly on the abundance of the parental stock, or spawning
stock biomass (SSB), calculated from the maturity ogive (Mace and Sissenwine, 1993; Rodgveller et al.
This eighth year of the Project continues the work of improving spawning
and rearing habitat for steelhead trout and Chinook salmon in the lower American River.
In each mesocosm, a single 10 x 20-cm weighted scouring pad was added (prior to the addition of residents) to provide a spawning
behavior of Lingcod has only been observed and described once in the literature (Wilby 1937).
The stage-specific and seasonal variation of oocyte size frequency distribution, seasonal variation in the percentage of different oocyte stages in individuals in spawning
capable phase, and seasonal variation in the mean diameter of oocytes in the tertiary vitellogenesis stage in individual in spawning
capable phase through spawning
season are required (West, 1990; Hunter and Macewicz, 1985c; Murua et al.
can alter the physiological state of females, leading to their reproductive exhaustion as a result of insufficient time for storage of reserves in the hepatopancreas and their transport to the ovary (Primavera, 1985; Harrison, 1990).
However, its pattern of asynchronous spawning
and low fertility, associated with environmental factors in the reproductive cycle such as photoperiod, temperature, nutrition, salinity and rainfall (Coward & Bromage, 2000) are a challenge for fingerling supplies.
This will add to its appeal for vocational programs and for readers who wish more information on beach-spawning
fishes due to personal interest in popular spectacles like grunion spawning
in California, or for work in conservation or land-use planning.
is inextricably linked to exogenous environmental cues and may be controlled by the interaction of photoperiod, water temperature, and discharge, as well as by endogenous physiological cycles (reviewed by de Vlaming, 1972).
THE number of trout spawning
in a County Durham stream is on the increase.
CVF&CA member Chris White said the spawning
season, from November to the end of January, was vital for salmon prospects.
Many anglers consider the spring spawning
season the most exciting time of the year.