Reproductive investment in the Silurus meridionalis |
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Authors: | X. Xie T. Long Y. Zhang Z. Cao |
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Affiliation: | Department of Biology, Southwest China Normal University, Chongqing 400715;Department of Biology, Chongqing Teachers' College, Chongqing 400047, P. R. China |
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Abstract: | A comparison of pre- and postspawning Silurus meridionalis showed that 20·7% of body stored energy was utilized during spawning for a standard male (74·5 cm) and 23·8% for a standard female (85·3 cm). About one-third of the loss of the stored energy was released as eggs by females, and almost all of the energy loss for males and about two-thirds for females were expended in metabolism. Stored lipid as fuel for metabolism supplied 90·0% of energy in males and 95·2% in females, and protein supplied the rest of the energy. Models for predicting energy in released gametes ( G g), deposited in the body as somatic growth ( G s), utilized in spawning activity ( S a), expended in maintenance ( M , including metabolism, faeces and excretion), and food energy ( C ) were developed, and annual energy budgets were compiled. The balanced budget for a male aged 4 was: 100 C =0·06 G g+11·17 S a+19·5 G s+69·2 M , and for a female aged 5: 100 C =5·48 G g+8·51 S a+15·8 G s+70·2 M . |
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Keywords: | fish energetics energy budget reproduction Silurus meridionalis Three Gorges Dam |
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