Open Access. Powered by Scholars. Published by Universities.®

Aquaculture and Fisheries Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 5 of 5

Full-Text Articles in Aquaculture and Fisheries

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 Dec 1998

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 …


Food-Limited Growth And Condition Index In The Eastern Oyster, Crassostrea Virginica (Gmelin, 1791), And The Bay Scallop, Argopecten Irradians Irradians (Lamarck, 1819), Michael A. Rice, Robert B. Rheault Jr. Dec 1995

Food-Limited Growth And Condition Index In The Eastern Oyster, Crassostrea Virginica (Gmelin, 1791), And The Bay Scallop, Argopecten Irradians Irradians (Lamarck, 1819), Michael A. Rice, Robert B. Rheault Jr.

Michael A Rice

The growth response of the eastern oyster, Crassostrea virginica, and the bay scallop, Argopecten irradians irradians, to varying degrees of food limitation was evaluated. Under conditions of low current speed, dense assemblages of shellfish can rapidly deplete ambient food concentrations, resulting in measurable effects on growth and condition index. A flume study demonstrated significant growth and condition index responses to resource competition after reductions as small as 27% in relatively high ambient food concentrations (—4.6 u.g/1 chlorophyll). Growth rates and condition index are linearly correlated with the average chlorophyll ration consumed. A field study demonstrated similar growth responses when the …


Experimental Culture And Particle Filtration By Asian Moon Scallops, Amusium Pleuronectes, Michael A. Rice, Robert B. Rheault, Miguel S. Perez, Vicente S. Perez Sep 1994

Experimental Culture And Particle Filtration By Asian Moon Scallops, Amusium Pleuronectes, Michael A. Rice, Robert B. Rheault, Miguel S. Perez, Vicente S. Perez

Michael A Rice

Growth rates were determined for scallops (35-75 mm valve height) held in pocket nets and lantern nets at varying densities. The Ford-Walford linear transformation of the von Bertalanffy growth equation was used to allow quantification of food-limited stunting. Pocket nets allowed for greater growth of scallops than did the lantern nets at all stocking densities. The growth rates of scallops in pocket nets, nevertheless, were well below the growth of scallops in the wild. Clearance rates of Caribbean strains of Isochrysis galbana (C-ISO) and Chaetocerous gracilus (C-Cg) were determined for moon scallops. Amusin pleuronectes, in static chambers at 28ºC. The …


Uptake And Internal Distribution Of Exogenously Supplied Amino Acids In The Pacific Oyster, Crassostrea Gigas (Thunberg), Michael A. Rice, Grover C. Stephens Apr 1987

Uptake And Internal Distribution Of Exogenously Supplied Amino Acids In The Pacific Oyster, Crassostrea Gigas (Thunberg), Michael A. Rice, Grover C. Stephens

Michael A Rice

A technique is described in which irrigation of the mantle cavity of oysters, Crassostrea gigas, induces pumping at steady rates. Simultaneous net influx of 10 amino acids (asp, glu, asn, ser, gly, tau, ala, val, phe, lys) is observed by high-performance liquid chromatography (HPLC). Individual amino acids exhibit first-order exponential depletion from an initial medium concentration of 2.0 μM. Influx of radiolabeled alanine corresponds very closely to net entry of alanine as estimated by HPLC. Therefore, net entry of alanine from dilute solution (5 μM) occurs. The entry of alanine is well described by Michaelis-Menten kinetics with a maximum influx …


Transport Of Dissolved Amino Acids By The Mussel, Mytilus Edulis: Demonstration Of Net Uptake From Natural Seawater, Donal T. Manahan, Stephen H. Wright, Grover C. Stephens, Michael A. Rice Mar 1982

Transport Of Dissolved Amino Acids By The Mussel, Mytilus Edulis: Demonstration Of Net Uptake From Natural Seawater, Donal T. Manahan, Stephen H. Wright, Grover C. Stephens, Michael A. Rice

Michael A Rice

High-performance liquid chromatography provides direct evidence for substantial removal of naturally occurring specific free amino acids during a single passage of water through the mantle cavity of mussels. This occurs during the few seconds required for passage of the water across the gill, and removal proceeds unabated at ambient concentrations as low as 38 nanomoles per liter.