| Popis: |
Growth and survival of scallop Lyropecten nodosus were studied fromJuly to November 1997 using three bottom culture methods, (1) in corrals,(2) in pockets, and (3) in anchored sleeves. All size parameters studied (dryweight of the muscle, gonad, remaining tissues and shell, and shell length)showed significant differences due to culture method. The body componentswere larger for scallops in corrals than for those in pockets and greater forthose in pockets than in sleeves. In contrast, survival did not vary withculture method. Tissue components increased rapidly during the first 2months, when temperatures were lower and phytoplankton abundant(upwelling and transition periods). Subsequently values leveled off, or insome cases (muscle) decreased, and this coincided with stratification of thewater column and associated high temperatures and scarce food resources(and possible energetic demands for gonadal development). In contrast,shell weight and length showed no apparent affect of the environmentalchanges. The increased growth in the corrals was possibly because thecorral walls permitted the scallops to raise themselves off the bottom whichcould have provided greater access to food resources (suspendedparticles), or to better quality food. |
Full text from SpringerLink