A QUANTITATIVE METHOD FOR STAGING PENAEID PRAWN OVARIES USING IMAGE-ANALYSIS

A quantitative method of staging reproductive development based on the use of cell measurements and computerized image analysis of histologi cal sections is described. The method has been applied to samples of e astern king prawn, Penaeus plebejus, collected in Queensland, Australi a. Luminance measurements of selected tissue structures within the ova ry were used to determine three luminance ranges which characterized o varian development in histological sections. Cell diameter, average lu minance 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 successf ully separated maturing, mature and resorbing groups in 94% of the sam ples, but discrimination of stages within the above groups was as low as 30%. The estimated discriminant functions suggest there is a contin uum of development which can be characterized by a combination of meas urements obtained from histological sections.