On an abnormality in the penaeid prawn Metapenaeus affinis (H. Milne Edwards)

Abstract

Structural abnormalities in the genital organs of decapod crustaceans have been observed by several authors (Marshall, 1902; Hay, 1905; Ridewood, 1909; Matsumoto, 1955 ; Gordon, 1957 and HartnoU, 1960). George (1963) has reported the occurrence of an undeveloped petasma in the first pleopod of a female specimen of the prawn Metapenaeus tnonoceros (Fabricius). During the course of a routine observation on trawl catches off Cochin an abnormal specimen of Metapenaeus affinis (H. Milne Edwards) possessing both male and female external genitalia (Fig. 1) was collected in November 1967, from a depth of about 25 metres. The specimen measured 152 mm. in total length and 41 mm. in carapace length.