Some observations on the spawning behaviour of mackerel

Past investigations have shown that the Indian mackerel has a prolonged spawning season which extends approximately to four or five months (Devanesan and Chidambaram, 1948; Chidambaram et al, 1952; Bhimachar and George, 1952; Sekharan, 1958). During this period it is believed that the eggs are spawned in a number of successive batches though, so far, there has been no definite proof of it. From the patchiness of distribution of the transparent ova in the ovary Pradhan (1956) had suggested, that only a small percentage of the ova mature each time. Subsequently, more information was brought forth by Sekharan (1958) which indicated the possibihty that the ova are ripened and released in batches. The following is a discussion of the observations on the ovaries of mackerel collected from Portonovo which lend further support to this inference though, however, in regard to certain details Sekharan's observations appear to be somewhat different