Effect of temperature on gonad development of the Pacific geoduck clam (Panopea generosa Gould, 1850)

Autor: Christopher M. Pearce, Robert Marshall, R. Scott McKinley
Rok vydání: 2012
Předmět:
Zdroj: Aquaculture. :264-273
ISSN: 0044-8486
Popis: Temperature is well known to be a significant factor influencing bivalve gonad development and has major implications for the success of broodstock conditioning in a hatchery setting. Little is known, however, about how temperature affects the reproductive development of the Pacific geoduck clam, Panopea generosa, despite it being a major commercial species. To determine the appropriate broodstock conditioning temperatures for this species, adults were held in the laboratory for 155 days at fixed temperatures of 7, 11, 15, and 19 °C. Clams held at the two lower temperatures (7 and 11 °C) displayed a more advanced state of reproductive development than those at the two higher temperatures (15 and 19 °C). Significantly higher percentages of individuals with mature gonads were noted at 7 and 11 °C than at 19 °C and significantly more oocytes follicle− 1 were evident at 7 and 11 °C than at 15 and 19 °C. Clams in the 7 °C treatment had a significantly higher gonadosomatic index than those in the 11 °C one (which were not significantly different from clams held at 15 or 19 °C), but that was likely because there was a significantly lower incidence of spawning activity at 7 than at 11 °C. The 11 °C treatment had a significantly higher overall percentage of individuals spawning between weeks 15 and 17 of the experiment than any of the three other temperature treatments. Gonads of individuals in the 19 °C treatment degenerated, with 0 oocytes follicle− 1 and 90% of the gonad occupied by connective tissue after 113 days. In a hatchery setting, P. generosa should be held at a temperature of 11 °C if reproductive output is to be maximized. Lower temperatures (e.g. 7 °C), however, could be used to hold ripe broodstock for extended periods.
Databáze: OpenAIRE
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