Effect of kisspeptin on change in level of reproductive hormones and gonadal maturation in air breathing fish, Channa striatus
Kisspeptin-10 is a very potent stimulator of the gonadotropic axis. Steroid hormone level was higher in murrel injected with natural kisspeptin-10 at 0.01 and 0.05 µg/g body weight of male and female fishes, respectively than the control. Efficiency of natural kisspeptin-10 compared with GnRH analogues and pituitary extract on gonadal maturation of Channa striatus showed that natural kisspeptin-10 injected fish had highest values of GSI, fecundity, ova diameter and steroid hormone levels.
Effect of synthetic kisspeptin-10 compared with natural kisspeptin-10 on the gonadal maturation of striatus showed that natural kisspeptin-10 had slightly higher effect than synthetic kisspeptin-10 on the gonadal maturity.
Synthetic kisspeptin-10 also responded well in breeding of murrels in pond after injection. But, in artificial fertilization, synthetic kisspeptin -10 responded well in females but not in males (especially during final spermiation). The effect of synthetic kisspeptin -10 tested on the induced breeding of Indian Major Carps was found satisfactory.
Murrel (Channa Striatus)
Injection of Hormone
Implantation of Hormone
Matured Ovary
Section of Ovary at the End of Experiment
Section of Testis at the End of Experiment
Effect of synthetic kisspeptin-10 (mammalian) on the gonadal maturation of Striped Murrel, Channa striatus (Bloch)
In three synthetic kisspeptin-10 injected male fishes at the rate of 0.4 µg/g of body wt, the level of testosterone increased to 10.53 ng/ml of blood, as compared to control with 2.2 ng/ml of blood.
Estradiol level increased and the maximum level was 9662 pg/ml of blood (at 1 µg/g of body wt), 9681 pg/ml of blood (at 0.2 µg/g of body wt) and 9693 pg/ml of blood (at 0.4 µg/g of body wt).
GSI value fluctuated and the maximum GSI at the end of the sampling period was 1.11 at 0.2 and 0.4 µg/g body wt in synthetic kisspeptin-10 injected male fishes. Maximum GSI of > 6 was observed at higher concentrations in female fishes.
Maximum fecundities of 10124, 10224 and 10426 were observed from the synthetic kisspeptin-10 injected fishes at 0.1, 0.2 and 0.4 µg/g body wt, respectively in December, 2012, and lower fecundities from January, 2013 to March 2013. Maximum fecundity of > 12000 was observed at all concentrations of hormone treated fishes in May 2013.
Assessment of indigenous ornamental fishery resource of Tamiraparani River
A total of 12 ornamental fish species have been collected and recorded during the study. The species recorded includes Puntius sarana, P. chola, bimaculatus, P. filamentosus, P. tamiraparani, Etroplus suratensis, E. maculatus, Glassogobius giurus, Mystus oculatus, Ompak bimaculatus, Salmobhasia bacaila and Danio aequipinnatus.
In the present study, the numbers of species and their occurrence have been observed to be more in Tirunelveli than other two studied sites of Tamiraparani riverine system. Of the twelve species, Etroplus suratensis and Puntius sarana are abundant in all the three stations. Etroplus suratensis and Puntius sarana showed year round occurrence at Tamiraparani riverine
