A study on organization and cell and tissue characteristics in growth process of knifefish's the gonad at Thua Thien Hue was conducted during in the 2012, Results of the study have shown that the growth of sex cell and gonad of knifefish has morphotological, tissue and cell, which are similar to other species of Osteichthyes, experiencing 4 periods growth of sex cell and 6 maturational stages of gonad (including the ovarium and sperm). Organization and cell and tissue's characteristics have also shown that Notopterus notopterus spawns many times in its natural spowning season and in life. The absolute and relative fecundity of knifefish are not high. The absolute fecundity of knifefish ranges from 1377 to 4862 eggs, which depends on the fish's body length and weight. The relative. fecundity of knifefish doesn't fluctuate dramatically in comparison with fish's length and weight in different age groups, from 17 to 19 eggs/g of female fish, in which the body's weight and length of female fish ranged from 81 to 283.5g/individual and from 178 to 352mm/individual, respectively. The 2+ age group have the highest relative fecundity with 19 eggs/of female fish; and 1+ age group have the lowest relative fecundity with 17 eggs/of female fish. That have shown knifefish's reproductive capacity is not hight However, knifefish are multiparous species in spawning season. Therefore, its life so can change this problem. In addition, conservation of reproductive capacity of knifefish population can be assured in the nature at Thua Thien Hue and the Central Highland areas.
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