CHAPTER ONE
1.0 INTRODUCTION
Aquaculture, the farming of aquatic organisms including fish,
mulluscs, crustacean and aquatic plant is necessary to meet the protein
need of Nigerians. Overtime, there has been increase in fish production
in Nigeria. Despite this increase in fish production, the desired result
has not been attained. Quantitatively, details of fish production as at
2005 stood at 490,600 tons (FAO, 2003) from the artisan fishery, 56,300
tons from industry fishery through the use of trawlers, while fish
importation stood at 61,150 tons. In meeting up with the growing need
for fish production, aquaculture practice has been identified as a
possible alternative, the reasons being that the activities of artisans
and industrial fishery in our natural waters have led to over
exploitation and degradation due to human activities in our coastal
water. To fully bring aquaculture to its desired level, four production
challenges have been identified. These are the challenges of feeding the
fish stock in the pond, management of pond water supply, fish seeds
provision and pond construction/establishment. The first two challenges:
fish feeding and water quality management affect each other. The level
of feeding of the stocks affects the water quality and the level of
water quality affect the feeding performance of fish in the pond
(George, 2001).
Fish like other animals need food to be able to carry out their
metabolic activities. In aquaculture, fish feeding is either
supplemental or complete (total supply). Supplemental feeding is when
feeds are given to the animal at a minimal level to add to the natural
food available for the fish in the pond water. These natural foods are
in the form of phytoplankton and zooplanktons. The complete feeding is
when the source of food fed to the fish is solely supplied by the
farmer. In whichever case, the type of feeding practiced depends on the
nature of the pond and the type of production the farmer is involved
with (Michael, 1987; Michael et al., 2005).
The most popular cultured fish in Nigeria is the Catfish. It is
naturally carnivorous, a bottom pond dweller, nocturnally very active
and belongs to the family of Claridae (Willian, 1967; Idoho-Umeh, 2003).
However, with the fish domestication, its modes of feeding and
activities have been destabilized and modified. To this end, the feeding
regime has become diverse but the thumb rule of feeding stock at
optimum level should be very economical so as to have savings in feed
cost and the overall economic justification. Webster et al.,
(1992) reported that catfish can be fed once or twice daily and rainbow
trout at three times a day. In whichever case, the type of feeding
practiced depends on the nature of the pond and the type of production;
climatic condition and economic status of the farmer dictate the feeding
requirement.
Various studies have been done in fish feeding (Collins and Delmendo,
1979; Sena and Brain, 1992) but much is still to be done in the area of
the best time of the day and frequency to feed catfish so as to have
good growth performance that will justify the high cost of feeding
provided by the farmer. Determining the best frequency of feeding the
catfish is therefore expected to help to maximize performance,
discourage waste, and ensure the success of the enterprise. This will
help to discourage the deterioration of water quality which may arise
from the decomposition of feeds fed to the fish due to feeding at
inappropriate time and frequency. This in turn is expected to help to
minimize fish mortality due to pond water quality deterioration. The
Overall production of the stock will also be enhanced (Norm, 2000).
Hence, the need to study the growth performance of Clarias gariepinus fed
at a frequency of once and twice daily for an enhanced yield derived
from better and faster growth for production of the catfish.
1.1 AIM AND OBJECTIVES
The aim of this research is to feed Clarias gariepinus at different frequencies of once and twice daily with the following specific objective:
· to determine which of the feeding frequencies is more economical in the rearing of Clarias gariepinus.
1.2 JUSTIFICATION
This study is useful to fish farmers as it is expected to create
awareness on the appropriate feeding frequency that can yield better
growth in Clarias gariepinus culture. It is also expected to
enable aqua culturists to be aware of the best economical method that
yields better growth in different feeding frequencies within a short
production period. Finally, the results are expected to be useful to
commercial fish farmers in making managerial decisions in the production
of Clarias gariepinus