The relationships between the gametogenetic status of triploids or diploids of Manila clams, Tapes philippinarum, and their oxygen uptake and gill particle transport

Abstract

Prior to sexual maturity, diploids and triploids of the Manila clam, Tapes philippinarum, showed no significant difference in weight-specific oxygen uptake rates. After sexual maturity, however, oxygen uptake in triploids became significantly higher than in diploid clams. The oxygen uptake studies on isolated gill tissues of Manila clams revealed the degree of metabolic cost enhancement associated with gametogenesis in diploids and triploids. Diploids, in which gametogenesis proceeds normally, showed the highest increase in gill tissue respiration rates with sexual maturity, recording a 49% increase over immature diploid gill tissue. Gametogenesis is usually impaired in triploids. In triploid Manila clams, sexual maturity elicited increased gill respiration rates only in females, showing a 39% increase over triploid immature gills. Although the gill respiration rate of sexually mature triploid males was not significantly different from that of immature triploids, it exceeded that of immature diploids by 27%. Gills of mature triploid females respired at a faster rate than did mature triploid male gills or mature diploid gills. Dry body weights of mature clams showed diploid females to be heavier than triploid females or diploid males, whereas diploid males were not significantly heavier than triploid males. Significant differences were not observed between gill particle transport rates of diploid and triploid clams. © 1993.