Open AccessTHE EFFECT OF FEED DENSITY ON THE GROWTH OF JUVENILE Mercenaria campechiensis , THE SOUTHERN HARD CLAM 1
Author(s) -
Goldstein B. B.,
Roels O. A.
Publication year - 1980
Publication title -
proceedings of the world mariculture society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.655
H-Index - 60
eISSN - 1749-7345
pISSN - 0748-3260
DOI - 10.1111/j.1749-7345.1980.tb00113.x
Subject(s) - zoology , population , nitrate , seawater , mercenaria , urea , nitrite , juvenile , shellfish , chemistry , effluent , biology , growth rate , food science , environmental engineering , fishery , biochemistry , ecology , aquatic animal , demography , geometry , mathematics , sociology , fish <actinopterygii> , engineering
A Tahitian strain of Isochrysis sp. was grown in outdoors continuous culture and fed to juvenile Mercenaria campechiensis at five different cell densities: 5times10 5 , 1times10 5 , 5times10 4 , and 1times10 4 cells/ml; these correspond to inflow algal protein concentrations of 56.01, 11.34, 5.15, and 1.28 μg‐at particulate protein nitrogen (PPN) per liter, respectively. A control group received only 1 μ‐filtered seawater. An additional control consisted of an identical experimental setup receiving 5times10 4 cells/ml, without animals. Each treatment went to duplicate populations of 100 animals of 0.1 g each. Each population had a whole wet weight of 10.0 g. The total flow rate to each population was 120ml/ min. The filtered seawater, algal culture, and effluent from each shellfish population was sampled daily. All samples were analyzed for nitrite, nitrate, ammonia, urea, dissolved free amino acids, soluble protein, total dissolved nitrogen, and particulate protein. The control treatment of 1 μ‐filtered seawater gave no growth. The most concentrated treatment (56.01 μg‐at PPN/1) gave good growth. However, better growth was obtained at concentrations of 5.75 and 11.34 μg‐at PPN/1. At the flow rates and population weights used, 56.01 μg‐at PPN/1 is too concentrated, resulting in poorer growth. The lease dense treatment (1times10 4 cells/ml or 1.28 μg‐at PPN/1) resulted in the poorest growth (other than the control). Under the experimental conditions used, this cell density apparently represents a suboptimum ration size. The effect of feed density on the growth of juvenile M. campechiensis is discussed in terms of traditional models of growth as a function of ingested ration.