LOGIN TO YOUR ACCOUNT

Username
Password
Remember Me
Or use your Academic/Social account:

CREATE AN ACCOUNT

Or use your Academic/Social account:

Congratulations!

You have just completed your registration at OpenAire.

Before you can login to the site, you will need to activate your account. An e-mail will be sent to you with the proper instructions.

Important!

Please note that this site is currently undergoing Beta testing.
Any new content you create is not guaranteed to be present to the final version of the site upon release.

Thank you for your patience,
OpenAire Dev Team.

Close This Message

CREATE AN ACCOUNT

Name:
Username:
Password:
Verify Password:
E-mail:
Verify E-mail:
*All Fields Are Required.
Please Verify You Are Human:
fbtwitterlinkedinvimeoflicker grey 14rssslideshare1
*(1), Mohsen Abdel-Tawwab (2005)
Publisher: Turkish Journal of Fisheries and Aquatic Sciences
Journal: Turkish Journal of Fisheries and Aquatic Sciences
Languages: English
Types: Article
Subjects: Nile catfish, Clarias gariepinus, predator, Nile tilapia, Oreochromis niloticus, prey, stocking ratio, artificial feeding, macrophytes
The overpopulation of tilapia in confined ponds is an obvious problem, and causes stunted growth due to the shortage of natural food, particularly in semi-intensive culture. However, the control of tilapias population by predator culture has been practiced worldwide. The factors affecting predation efficiency of Nile catfish, Clarias gariepinus (B.) for controlling the overpopulation of Nile tilapia, Oreochromis niloticus (L.) were studied in four indoor experiments. Nile catfish with different sizes was stocked with tilapia fry (2-3 g) at the ratios of 1:10 or 1:15 (catfish : tilapia) without feeding. In another trial, Nile catfish : tilapia (1:15 ratio) with different sizes was frequently fed to satiation with fish diet (25% crude protein). The number of eaten fry was counted after 6, 24, 48 and 72 hours. The predation rate of Nile catfish at different predator sizes increased at the ratio of 1:15 more than 1:10 (catfish : tilapia) ratio. Predation rate of large Nile catfish was greater than small ones. Artificial feeding reduced the predation rate of Nile catfish at different predator sizes, while it increased with increasing predator size and tilapia stocking. In the fourth experiment, the leafless stems of phragmites plants (0.7 m long and 0.5 cm diameter) were used in this study at densities of 0, 5, 10, 20, 30 and 50 stems/m2. The aquarium was stocked with 15 fry (2.2 g) and 1 catfish (400 g). The number of eaten fry was counted closely for 6, 24, 48 and 72 hours. The fry used the submerged macrophytes as a refuge to protect themselves from predator attack. It was concluded that predation rate of Nile catfish is dependent on predator size, prey stocking density, supplemental feeding and period of stocking. Moreover, the presence of submerged vegetation at moderate density (20-30 stem/m2) may reduce the number of eaten fry.
  • No references.
  • No related research data.
  • No similar publications.

Share - Bookmark

Cite this article