During the course of investigation on the life-history of Selaroides leptolepis  a common carangid in the Palk Bay and tbe Gulf of Mannar in the vicinity of Mandapam- it was observed that males mature slightly earlier than females. This phenomenon has been observed, in other fishe

Tandon, K K

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258 SCiENCE AND CULTURE Vol. 27, No. 5 Size at firs t JDaturity in SeloToides lep· tolepis (euvier and Valenciennes) a s evidenced by the occurrence of individuals in the Com.mercial Catches )Juring the course of investigation on the life-history of Selaroides ltptoltpis4,&,e- a com,rnon carangid in the Palk Bay and tbe Gulf of ?\1annar in the vicinity of Mandapam- it was observed that males mature slightly earlier than females. This phenomenon has al 0 been observed, in other fishes 1,3. Examination of fish during the months of July to September in 1957 and 1958, and again during January to March 1958 and 1959 indicated that males mature earlier than females. It was found that ill July to Septem-ber 1957 samples (fig. I) 17.4 per cent of the 100 \\0 60 1. 40 20 0", .. .... .. ....". ~ '" .' 1.., - JULY . SEPT. 'S7 / ,r - __ JULy - SEPT.'SB (,' .... _.:. JANrMARCH'SB /1 • -c. - JAN.-MARCH'59 , I / i I • I 6 'T a !2 '" ~ ,,; :J: ./ ;! SIZE GROUPS IN CM. Fig. I. Sjze at first maturity in males as evidenced by the OCcurrence or mature indi'-iduals during the spawning seasons. males reached first maturity in the group 9.1 to 9.5 cm. and jn the subsequent groups the percentage of the mature males increased considerably. All individuals above 11 .0 em. were mature in the catches. In Jul y to Septem-ber 1958 samples fir" sign of maturity in males May, 1961 LE'l'T~RS TO THE EDlTOU 259 appeared in the size 8.6 to 9.0 em., when only 4.2 per cent were mature. Examination of samples in the months of January to IVlarch 1958 and 1959 re\'ealed that mature indi\'iduals first appeared in 9.6 to 10.0 cm. and 10.1 to 10.5 em. groups respecti\-ely. On the basis of four spawning seasons it may be concluded that males first mature at about 8.7 em. Females were first noticed to mature in 8.6 to 9.0 cm. group (fig. 2, in the samples of 100 ao 60 0' ,. <0 2 0 0", ~ ':t cO 01 SIZE ~ (j __ JULY _ SEP"[ IS7 __ JULY - SEPT. ' 58 ___ _ JAN.- MAI<CH '56 _._JAN.-MARCH ' S9 ~ ., '" :l ,.; GROUPS IN CM Fig. 2. Size al fll'SL lUaturity in females as evidenced b\' tlle occurrence or mature individuals during the spawning scasoru. Jul)' to September 1957 when +.7 per cent attained malurit\". All the females at 11.0 em. and above wCl:e mature. In tbe July [0 September 1958 samples, size at first maturity in females was recorded in the group 9.1 to 9.5 em . Similarly in the Janu.ary to March 1958 and 1959 samples mature females were noticed in the group 9.6 to 10 .0 COl . It rna)" thus be concluded [rom fig. 2 tha t female.> firs t start maturing when they arc about 8.8 CI11 . in length and this was abo confirmed by the ova diameter studies. Prabhu:! found that females mature at 13.9 em. whieh is significantly different from the present obser-vations. My thanks are due to Dr. S. Jones, Cllief R esearch Officer, and Dr. R. Raghu Prasad, Senior R esearch Officer, Central ~1arine Fisheries R esearch Station, ~1andapam Camp for their encouragement during the course of 7 the investigation and LO the GO\'cl'nment of India for the award of Senior Scholarship. Department of Zoology, Banaras Hindu Universil\, Varanasi. . 17-1 - 196 1 K . K . TANDOlli 1 H. M. K)'lc, TluBiologyofFishts. Londoll, 192G. :I M. S. Prabhu Indian], Fish. 3, 59, 1956. C. Seshappa & B. S. Bhimachar. Ibid.. 2, 180, 1955. " K . K. Tandoll, Ibid, 7, 1960 (in Pre;s) K . K. Tandon. Unpublished, G K. K. Tandon, Curro Sci., 29, 62. 1960. 

Size at first maturity in Selaroides leptolepis (Cuvier and Valenciennes) as evidenced by the occurrence of individuals in the commercial catches

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Size at first maturity in Selaroides leptolepis (Cuvier and Valenciennes) as evidenced by the occurrence of individuals in the commercial catches

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