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Showing posts from October 15, 2017

THREE MAJOR EDIBLE SNAIL SPECIES OF AFRICAN ORIGIN

by Chigbogu, Nnachetam The two most popular edible snails in West Africa are the giant snail, Achatina achatina , and the big black, Archachatina marginata . Most studies on snails in West Africa have concentrated on these two species and on the garden snail, Achatina fulica . In Ghana Achatina achatina is considered the most prized species for eating, followed by Archachatina marginata and then Achatina fulica . Other edible species exist, but they are of minor, local importance. Achatina achatina Common name: giant snail, tiger snail (Ghana)\ Description: Achatina achatina can be considered a good candidate for snail farming in most areas of West Africa, although it requires higher humidity than the other two species and needs a longer growing time to reach sexual maturity. They are reputedly the largest land snails in the world. Although usually much smaller, they can grow up to 30 cm in body length and 25 cm in shell height. Average adult shell length is 18cm,

CANNIBALISM AMONG CATFISHES

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by Chigbogu, Nnachetam Catfishes exhibit the EAT OR BE EATEN contest , which this term cannibalism describes. Cannibalism is the process whereby a fish eats another fish. This is a very common phenomenon among catfishes. Because, catfishes are omnivorous in nature, they tend to cannibalize on themselves, and because, although they are hatched the same time but do not have uniform growth rate, they tend to be cannibalistic in nature. Due to the lack of uniformity in their growth rate, the ones that shout-out faster (shooters) tend to predate on the smaller and weaker ones. Catfishes cannibalize a lot, when they are left for a long time in a pond without sorting, or when they are not being fed adequately. Catfishes start cannibalizing early in their life time (from fry/post-fry stage), and this has been a major and common problem for catfish farmers. Types of Cannibalism There are two major types of cannibalism among catfishes, namely; a.        Head cannibalism, and