FEEDING OF CATFISH OLARIAS LAZERA IN EXPERIMENTAL PONDS

FEEDING OF CATFISH OLARIAS LAZERA

IN EXPERIMENTAL PONDS

By
A.E. hIAM
Institute of Inland Waters and Fish Oulture

Barrage Fish Farm

and
H.M. ;ROUSRDY
Department of Radiobiology, U.A.R. Atomic Energy Establishment
and
A. l’HILIS’l’EEN
Institute of Inland Waters and Fish Oulture
Barrage Fish Farm

INTRODUCTlO:N
In fish culi-mc, the fecdirg prohl( ms COllBtit’lIte HCill’.e oftlle lllajor diffil-lIlties.
It is kEown t·}mt a S11 itll,ble did is th:.t whicb cal] provido thc fi..’:h with the raw
materinlR r,ece~;s[l,fy f(il’ n:e 1′]( dudi(,1\- (if flesh md to keep them in a llealthy
condition. Fn,m tl,C ppint cf \’iew pf pond Cll Iti\’at.ion cUJ)’Obl.y, food metabolism
in fish consists of tv.’O (‘r.mper.eds: a part or th(‘ metabolism serves to
sustain the body of the fi h and its funtie.]’ s, a1’d the other part cnters into
gro\vth a:r..d furtlier devdopn”J’rt. NpJUl a1)y, t1:e DEee l’ d fu1’ction is the
primary concern e,f the pond cultivator.
In order to fulfil almr darec of tre food requircment s of t1:e reared fh’lh in the
experimental pord,:. (,itIer the biJ,8ic production capncity of t·he pords may be
enharced through artificip.] f,·rtili7,iJ1g IT.eHods ny din t} i.’l \Vlwt!’.e nl:.tural food for
the fulh may he Dmliiplied ; or tlw r:aJl1r2.] foeld may he suppiimented or substituted with artificial aFd (‘coromic food. In hoth ca,sC’s a knowledge of t,he basic
llutritive rC’qllireIY’.<‘] ts of ille fi,;}l i,: rC’cded.
The individwd (‘ompe’IlC’llts of f1.1l food must he evaluated according to their
importance in Hie fi’,h rnek.bolism. Al t·ificia} food should in its composit,ion be
similar, aB far ns Jlos~.ib;e, to 1ktt of 1110 J1p,tura} food. For the composition, the
same basic rllkB apply for fish as for oiber animals. The orgar’ic nutrients;
protein, fat, carhe,Lydlate, minem]s ard vitamiNl are tlle d,ief constituents.
Proteirs a:r:d ol.rbu};ydrates pIny a n:.a.jor pm·tin determining the succeBS
or f8,ilure of any fiHh diet. Though fe\\’ studies have been made on Nle functions
ot proteins in t·he fiRh body, yet it may b8 2ossurr.ed that j hey are similar to those in
t,he bodeis of higher anim.als (PhJJipR nt a.l 1956).
It is known. however, that the pcrcent,age offood prot·ein that can be utilized
to Ratif\fy the protein needs of the fish body depends on the protein qua.lity of 1he
food. A protein food c,”n 1>e cnrr:idrred ,$ hifhest pTotrin quality if its ltm.]y,:is
is approxim?,ting to t·hat of the body pl’Otein, or if this protein food produceb the
best rate of growt.h (Wood, 1952).
Moreover, 1·he digestibilit’Y of a protein determinC’R the degree of its utiliRation
by a pa,rticular animal. Fresh meat products W8re found to be highly digestible
by carnivorous fish. F’esh lUNtt haR bcC’n found to promote trout growth and provide it with ccrt:.in diota.ry (‘”senti;],]:, (Phillips, 1956).
In contrast to 1,he In3,ny functions of protein in 1,}lC animal body, the role
of cp,rbollydrate is limited.
The amount of carbohydrate that may be added to fisll dietB BccmB to be
limited by t·he phy~iology of t,11e fish itDelf.
Moreover, f:\ts and miJlerals are know]’ to fonn t,wo ()f the ma.jor groups of
8uhstancefl 1,hat mllst be represented in the diet of fishes. It is }lOwever assllllled
that the illformation about the role of fa.ts in higher animals also gpplies to