A quantitative method for staging penaeid prawn ovaries using image analysis

Abstract

A quantitative method of staging reproductive development based on the use of cell measurements and computerized image analysis of histological sections is described. The method has been applied to samples of eastern king prawn, Penaeus plebejus, collected in Queensland, Australia. Luminance measurements of selected tissue structures within the ovary were used to determine three luminance ranges which characterized ovarian development in histological sections. Cell diameter, average luminance and percent area of an ovary section within a luminance range of 200–245 were the most useful variables to discriminate between the different ovarian developmental stages. Discriminant analysis successfully separated maturing, mature and resorbing groups in 94% of the samples, but discrimination of stages within the above groups was as low as 30%. The estimated discriminant functions suggest there is a continuum of development which can be characterized by a combination of measurements obtained from histological sections.