Open Access. Powered by Scholars. Published by Universities.®
- File Type
Articles 1 - 3 of 3
Full-Text Articles in Life Sciences
Gonadal Cycle Of Northern Quahogs, Mercenaria Mercenaria (Linne, 1758), From Fished And Non-Fished Subpopulations In Narragansett Bay, Dora Marroquin-Mora, Michael Rice
Gonadal Cycle Of Northern Quahogs, Mercenaria Mercenaria (Linne, 1758), From Fished And Non-Fished Subpopulations In Narragansett Bay, Dora Marroquin-Mora, Michael Rice
Michael A Rice
To determine if population density in areas closed to fishing in Narragansett Bay is causing differences in the reproductive potential of the organisms, this study used two approaches to determine the reproductive condition of the animals. The first approach consisted in employing a gravimetric condition index (CI) to evaluate the general condition of quahogs from nine different sites, 3 sites open conditionally for fishing (conditional areas) and 6 sites closed to fishing. The second approach was a determination of gonadal index (GI) of a subset of the sample sites, by histological observation of gonadal tissue sections. Initial sampling included determination …
Uptake Of Dissolved Free Amino Acids By Northern Quahogs, Mercenaria Mercenaria, And Its Relative Importance To Organic Nitrogen Deposition In Narragansett Bay, Rhode Island, Michael A. Rice
Michael A Rice
Studies were undertaken to determine the relationship between size of northern quahogs Mercenaria mercenaria and the rate at which they transport aspartic acid. Quahogs ranging from 25 to 103 mm valve length were collected in Narragansett Bay and placed in seawater aquaria (27 ppt, 20 deg C) and allowed to pump actively. Uptake experiments were carried out using 1 umol/L C(14) radiolabeled aspartic acid. Aspartate transport rates in umol/h can be related to valve length by the allometric equation with a = 24.32 and b = 0.905 when valve length is in mm. In May 1990, near bottom samples of …
A Review Of The Factors Influencing The Growth Of The Northern Quahog, Mercenaria Mercenaria (Linnaeus, 1758), Michael A. Rice, Jan A. Pechenik
A Review Of The Factors Influencing The Growth Of The Northern Quahog, Mercenaria Mercenaria (Linnaeus, 1758), Michael A. Rice, Jan A. Pechenik
Michael A Rice
Factors affecting the growth of larval, juvenile, and adult northern quahogs, Mercenaria mercenaria, are reviewed. Larval growth is affected by temperature, salinity, current speed, dissolved oxygen concentration, and the amount of suspended sediments in the water, along with such nutritional factors as food quantity and quality. Growth of post-set juvenile and adult quahogs is similarly affected by the same physical and nutritional factors. Recent work suggests that there is a strong genetic contribution to quahog growth rate and that selective breeding programs may be useful for producing rapid growth strains. A growing body of evidence suggests that larval growth rates …