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Abstract:
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Growth in individual weight (w, kg) of Kemp's ridley sea turtles (lepidochelys kempii) in captivity was described for 15 year-classes (1978-1992) of turtles between ages (t) 0.17 to 1.22 yr, using ln- linear regression: lnw = lnc + dt^1/2, where lnc is the intercept and d is the slope (growth rate index). There was significant (P < 0.001) heterogeneity in d among year-classes, with slowest growth (d = 3.798) exhibited by the 1983 year-class and fastest growth (d = 6.929) by the 1985 year-class, but there was no significant trend in d (P = 0.307) over year-classes. The variance of residuals from regression, s^2(reg), ranged from 0.2032 for the 1978 year-class to 0.0075 for the 1992 year-class, and showed a significant (P = 0.0001) logarithmic decrease over the year-classes. This decline in variation among individuals was probably due to a shift toward sex ratios dominated by one sex (females), improvements in rearing facilities, year-around control of seawater temperature which reduced disease incidence, improved diet, and reduced feeding levels. The relationship between w and scl (straight carapace length) was also described. |