This information bite illustrates the accumulated gain over generations through selection. The bite also describes the factors that influence the response to selection which are namely heritability coefficient and selection differential. The illustration shows the declining gain (response to selection) till reaching the plateau whereas no gain could be achieved unless variation is created naturally …
Category: A.A. EL GAMAL
Items under ownership of Abdel Rahman El Gamal, PhD
Permanent link to this article: https://fishconsult.org/?p=3497
May 13 2012
Genetic Environment Interaction (GxE) in Fish
This illustrated bite shows how the growth rate of two strains of a given species when grown in two different farming environments. The examples of the “No GxE) as well as the existence of the GxE has been illustrated. The two experimental environments are defined. The bite emphasized that these information should result of well designed experiment …
Permanent link to this article: https://fishconsult.org/?p=3488
Apr 28 2012
Longevity in Fishes
This large bite does not only address the definition of longevity and related terms (e.g. lifespan) but also covers with examples the factors affecting longevity. For a valid illustration, a Table with maximum longevity has been included whereas clear differences among various fish groups could be easily noticed. The application of longevity in fishery and aquaculture practices has …
Permanent link to this article: https://fishconsult.org/?p=3431
Apr 22 2012
Water transparency measurements using Secchi disk
This information bite handles a practical pond management issue as well as a field tool which is Secchi disk. The use of Secchi disk in measuring water transparency has been covered in the attached information providing adequate background such as sources of turbidity in water as well as factors to considered during measurement. Relating the …
Permanent link to this article: https://fishconsult.org/?p=3404
Apr 07 2012
Artificial reproduction of African catfish (Clarias gariepinus) – Egg stripping (Video)
Credit for the clip: Samuel Simon Zigizo (South Sudan) – Description: Abdel Rahman El Gamal This video shows the stripping of a female of African catfish, Clarias gariepinus. This practice takes place in artificial reproduction of the species and should be followed by artificial fertilization using testes taken from a sacrificed male. We are able to see …
Permanent link to this article: https://fishconsult.org/?p=3272
Mar 17 2012
Artificial fertilization of the eggs of African catfish, Clarias gariepinus (Video)
Credit for the video: Emmanuel Ohene Marfo (Ghana) Description: Abdel Rahman El Gamal Such as the case with silurid fishes, it is almost impossible to hand strip the sperm from the male of African catfish, Clarias gariepinus. Therefore and as seen in this video, testes of a sacrificed male are used for the artificial fertilization of catfish eggs. Testes …
Permanent link to this article: https://fishconsult.org/?p=3023
Feb 27 2012
Culture of Nile tilapia in integration with banana in Egypt
The two photos cover the overall integrated aquaculture-horticulture project. In this specific project, horticulture is represented by banana while Nile tilapia (Oreochromis niloticus) represents the aquaculture component. Because of water scarcity in Egypt, the surface irrigation of banana farming is not encouraged due to its high water consumption. In order to compromise between the restrictions …
Permanent link to this article: https://fishconsult.org/?p=2644
Feb 24 2012
Rigor mortis in fish and its relation to quality
This 4-slide information bite starts with an intoductory slide on the rigor mortis in animal in general including its causes and feautures. The remaining part of the bite focuses more on the rigor mortis in fish having in consideration the specific nature of fish as well as fishing and aquaculture practices. Emphasis has been placed on …
Permanent link to this article: https://fishconsult.org/?p=2620
Feb 21 2012
Possible use of plant compost in aquaculture
Credit of the photos: Photos used in this information bite have been taken from a pool of photos which was given to me by friends who participated in Warm water fish production during 2009 and 2010. Identified names are: shared with me from El-Sadig Arbab Hagar (Sudan) and Lylian Wilfred Mguhi Lugobola (Tanzania). Thanks to …
Permanent link to this article: https://fishconsult.org/?p=2598
Feb 05 2012
Fish ovulation and egg overripe
This 2-slide information bite addresses the ovulation of fish female in regard to timing and indicators. Focus has been placed on the importance of collecting the spawn short time after ovulation before eggs turn overripe which means losing the chance for fertilization. The period from ovulation and eggs turn overripe vary according to some factors …
Permanent link to this article: https://fishconsult.org/?p=2367