The purpose of the current study was to examine the effects of different feeds/nutrients and temperature on the gonadal development of Clarias gariepinus. The gonadosomatic index (GSI) HCT (29.06 ± 3.54%), PLT (90.75 ± 9.18/mm3), and MCV (118.08 ± 10.3 g/l). Fish meal diet revealed the most significant (p<0.05) increase in weight gain, female GSI, and also exerted significant increases on most of the blood parameters. This study revealed that animal-based protein diet and temperature around 28℃ were the critical requirements for the physiological performance and relative gonadal weight of C. gariepinus. GSI and blood parameters were useful indicators of stress exerted by nutrition and temperature on fish, and their study is critical for fish health and mass production of viable seeds for aquaculture enterprise.
The present work was conducted to elucidate the relationships between chronological age, testosterone concentration and testis size of Najdi and Naemi ram lambs under desert conditions to determine the reproductive capacity of the above two breeds. The postnatal development of the seminiferous epithelium of the testes was also monitored. A total of 90 (45 Najdi and 45 Naemi lambs) aged between one and nine months, with five lambs at each month of age for each breed were used. The results showed that the testosterone concentration increased dramatically and rapidly between five and six months, followed by a period of gradual growth where testicular size was increased from 3 to 6 months of age. There was a significant (P > 0.05) difference in testosterone concentration (TC) and testis size (TS) in ram lambs between different age groups, similarly there were significant differences between body weights and lamb age between one and nine months. A positive correlation between the increasing body weight and the size of the testicle was observed. The testicles of lambs at each age-group had a different histological appearance except those of Najdi lambs at 2, 3 and 4 months and Naemi lambs at 2, 3, 4 and 5 months, where few differences were apparent. Small quantities were of spermatozoa appeared at the eighth month of age and increased in the ninth month. In conclusion, the current findings indicate that puberty in Najdi and Naemi rams occurs at the 8th and 9th month of age, respectively.
The reproductive biology of the horned viper, Cerastes cerastes gasperettii, in Riyadh region of Saudi Arabia was investigated over a period of one year. Study of reproductive cycle of male and female C. c. gasperettii revealed that the breeding season is relatively short (April and May). Thereafter females laid eggs by mid of July and hatching probably had taken place by the end of September. No activity was observed during winter, this may indicate just a single clutch per year. Relative testis weight to body weight was drastically increased ([Formula: see text] = 0.88%) during the peak of reproductive activity (May) where maximal expansion of seminiferous tubules was also attained during April and May ([Formula: see text] = 209 μm and 191 μm, respectively). Likewise, the ovarian activity was the highest during May where ovarian parameters were greater in terms of relative ovarian weight to body weight and ova diameter being 0.46% and 2.29 mm, respectively. Fat body weight was increased drastically just before the peak of reproductive activity then started to decline during June. It could be concluded that the harsh desert conditions and similar environments certainly affect reproductive activity of Saudi Arabian reptiles including snakes.
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