Estimating the length of the exponential growth phase: Growth increment observations on the coral-reef asteroid Culcita novaeguineae

A method of estimating the length of the exponential growth phase is developed by solving a difference equation derived from the regression of growth increments on the initial sizes. This method facilitates quick assessments of the juvenile lifespan of animals, e.g. the coral-reef asteroid Culcita novaeguineae, which grow exponentially with very low growth rates. The juvenile life span of C. novaeguineae was estimated to be about 2 years from metamorphosis to transformation into the pin-cushion form.Supported by NSF Grant GA-39948. Contribution No. 87, University of Guam Marine Laboratory.