CATFISH PRODUCTION IN NIGERIA

O' GRACIOUS E-PLUS CATFISH FARM

Fish caught for production with scope net

In O’ Gracious E-Plus Farm artificial reproduction is the only practice use in production of fish. Before production of fish the following are to be ready:

·         Female brood-stock

·         Male brood-stock

·         Ovaprim

·         Saline

·         Mesh net

Female brood-stock

Matured female fish are selected according to the following criteria:

A well distended, swollen abdomen, sometimes reddish or rose coloured genital papilla from which ripe eggs can be obtained by slightly pressing the abdomen towards the genital papilla.

Male brood-stock

Mostly male that are above 1k is used in fish production at “OGEPF” ideally male fish should be larger than 500 grams and not less than 7¹/₂ months.

Ovaprim

Is the hormone use in the farm and is administered at 0.5m per 1kilogram of fish body weight. This is most common hormone use by fish farmers in Delta region.

Saline

This is prepare by mixing 9gram of NaCl with 1 liter of boiled water, or prepared. It is also sold in the market

Preparation of saline

Mesh net

This is made up of plastic pipe and a net (size 1mm).

 

 Mesh net use in incubation

Administration of Hormone

The most common method of administering the hormone is by intra-muscular injection into the dorsal muscle. The females are injected in the evening and are kept (separated from the males) in holding facility.

Administration of hormone in catfish dorsally

Note: Cover the head of the breeder with a towel in order to keep it quite during injection. In general most fish keep still if their eyes are covered and the holding facility which they are separated from can be a simple plastic bucket, vat or a half oil drum e.t.c for easy cash in the morning so as to avoid spoilage of eggs.

The time between injection and stripping depends on the water temperature. The time it takes egg to ovulate in accordance to temperature is presented below:

WATER TEMPERATURE		TIME BETWEEN INJECTIONS AND STRIPPING (HOURS)
20		21
	21	18
22		15.5
23		13.5
24		12
25		11
26		10
27		9
28		8
29		7.5

Extraction of Sperm

The milt is taken from a male spawner and diluted with a physiological salt solution (9g of kitchen salt (NaCl) dissolved in 1 litre of boiled water) about half an hour before the females are stripped.

                                                   Milt extraction process

Stripping

Stripping of the female spawners is carried out by gently pressing their abdomen with a thumb from the pectoral fin towards the genital papilla.

                                                                                   During stripping

Fertilization process of stripped Eggs

The sperm is added to the stripped eggs, is mixed with the eggs by gently shaking the bowl they become fertilize and an equal volume of water is added to the eggs to enable the damage eggs to flow on the water then we decant.

Note: Egg must be stirred continuously until they are placed in the hatching tanks reason is that the eggs become sticky and without stirring it will stick together into one clump. About 60 seconds after fertilization has taken place the sperm lost its activities; the fertilized eggs are then ready for incubation.

Incubation of fertilized eggs

The eggs are spread out on a screen (mesh size 1mm) which is placed on the hatchery and this process is called Casting. This method works well as the hatched fish will pass through the screen living the dead eggs and shells on the screen, the screen is removed from the basin separation the hatched fish and dead eggs.

Incubating of eggs by casting it on a mesh net

Time interval of incubation in relation to water temperature:

WATER TEMPERATURE IN CELSIUS	TIME INTERVAL OF INCUBATION (HOURS)
20	57
21	46
22	38
23	33
24	29
25	27
26	25
27	23
28	22
29	21
30	20