Replicate Ponds of 0.02ha stocked at 500 catfishes with 20,000 tilapia/ha were used to assess growth performance of O.niloticus, average weight 50.4g with (i) darted catfish; H.longifilis (shooters) average weight 60.3g (ii) non-shooters of H.longifilis, average weight 35.4g. Final mean weight, mean growth rate, specific growth rate and food conversion ratio were 499.5g 26g/day, 1.36% and 5.58% respectively for O.niloticus stocked with longifilis (shooters) and 440.4g 2.3g/day 1.23% and 5.58% respectively for O.niloticus stocked with H.longifilis (non- shooters) and 246.9g, 1.2g/day, 0.93, 6.30% respectively for tilapia in monoculture. The least growth was noted for O. niloticus in monoculture while the best growth was recorded O. niloticus in polyculture with darted catfis

Ayotunde, A.

Ikpi, G.

Ofem, B.

English

Aquatic Commons

EFFECT OF DARTING PHENOMENON OF AFRICAN CATFISH HETEROBRAiVCHUS
LONGIFILIS (BURCHELL, 1822) ON GROWTH PERFORMANCE OF NILE TILAPIA;
OREOCHNOMIS NILOTICUS (LINNAEUS, 1758).
B. OFEM*, G. IKPI, A. AYOTUNDE.
DEPARTMENT OF FISHERIES, FACULTY OF AGRIC AND FORES TY, CROSS RIVER
STATE UNIVERSITY OF TECHNOLOGY, OBUBRA C.R.S. NIGERIA
INTRODUCTION
Many fish farmers in Nigeria stock their ponds with tilapia in monoculture, but sometimes
with African catfish, although tilapia is always the focus of the enterprise in the country. It is liked
by many, and attracts good cash value; the feeds are cheap and affordable. The main problem in
tilapia culture is the early spawning and rapid overpopulation in ponds, which leads to, stunted
growth and poor performance (Dadzie, 1982). There is therefore need to improve in the system
especially if intended to capture more market.
The Polyculture of tilipia with catfish is well documented (Madu et al, 1987; pastastico et
al, 1982). In most of these culture catfish is used as predators to control tilapia population and
improve growth.
However, experiments have revealed low predatory performance of catfish in certain
stocks resulting in growth performance of tilapia that are not significantly (P<0.05) different from
those of monocultures. (Taege in press).
The occurrence in African catfish of offspring's with high growth superiority (darting) over
individuals of same age bracket; with more aggressive sibling connibalism have been reported
(Madu et al, 1987; Ewa-Oboho, 1998), but no research had been carried .out to assess the
performance of tilapia in polyculture with these fast growing (shooters) African catfish. This
research therefore attempts to isolate the fast growers of and to determine their effect on growth
performance of the nile tilapia (Oreochromis nilotocus).
METI-10DOLOGY
This study was carried out in the fish farm complex of the Institute of Oceanography
UniVersity of Calabar. Water source was a perennial reservoir and the experiment was performed
in a system with water flow of 2-3 Ilsec.
Matured breeders of H. longifilis and O. niloticus were collected from brood stock earthed
ponds and transferred to the indoor hatchery where they were sexed and tested for ripeness as
described by Daget and litis (1965) and teugels (1982, 1990).
24 BREEDING OPERATION
Breeding of catfish (H. logifilis) was carried out by hypophysation according to 'the
method described by legendry (1986) using purified carp pituitary extract at a dose of 4g/kg body
weight. Fertilized eggs were incubated in water with flow-through rate 1-3 Lrnin. Mean hatching
percentage was 80%.
2.2 LARVAL REARING AND GROWTH MONITORING
Hatchlings of H. longifilis were measured for total length and weight and distributed into
two 501 aquaria at dentisy of 18 larval/C and fed at 3% body weight (Ewa-Oboho etal 1998). Fry
869
were fed exclusively on live food (Zooplankton) within first 14 days (Hecht et al 1988) then later
wiih dry food in the form of crumbled non-pelletised feeds formulated according to Balogon and
Ologhobo (1989) with 40% protein. Fast growing (darting ) fish were identified and removed
every 7 days
2.3 FATTEHING (IF FRY
The two types of fry (shooters and non-shooters) of H. longifilis were transferred
separately into outdo& tanks at density 15 larva/m2 fed diet of 40% crude protein at 5% body
weight thrice daily, supplemented with zooplankton. Fingerlings were harvested 6 weeks later at
average weight; 35.4 and 60.3g for "non-shooter" and "shooter" respectively.
2.4 EXPERIMENT ON POLYCULTURE
Fast growing fingerlings (shooters) of H. longiflis (60.3g) and non-shooters (35.4g) were
separately stocked with mixed tilapia breeders (50.4g) in 0.02ha replicate ponds at density of
5000 catfish/ha with 20,000 tilapia/ha at 1:3 male: female sex ratio. Mixed sex tilapia in
monoculture at density 20,000 tilapia/ha and 1:3 male; female sex ratio was the control. Fish
were fed at 5% biomass with crumbled non-palletized feeds with 40% crude protein twice daily.
Twenty randomly selected fish were sampled for weight bi-weekly and at the end of 168 days
ponds were drained, total numbers and weight of fish noted. Physico-chemical parameters of
water used for all experiments were determined according to standard methods (APHA, 1985)
and presented in table 1. One-way analysis of variance (ANOVA) was used for all statistical
comparison of growth indices.
3 RESULTS
3.1 GROWTH PERFORMANCE
Table 2 shows the growth performance of 0. niloticus in Polyculture with "shooters" and
"non-shooters" of H. longifilis. The best performance was recorded in 0.nilotiacus stocked with
"shooters". The mean weight gained was significantly different (P<0.05) from 0. niloticus in
monoculture. However, no significant difference (P< 0.05) exists between 0. niloticus in
polyculture with shooters and those with non-shooters and between tilapia in monoculture and
those in Polyculture with non-shooters. Tilapia in monoculture show the least growth
performance. (Table II)
TABLE 1
Mean values of some ph sical and chemical parameters of water used for ex eriments.
870
Parameters Aquaria Outdoor ponds Growth ponds
Dissolved Oxygen Ing/IL 6.8 7.0 7.8
.
-1
Ammonia (mg/I) 0.1 0.04 0.06
__1
i___F_'H 7.5 8.8 8.0
----,-
Temp. (°C) 26.8 28.0 25.8
TABLE 2:
Growth performance of tilapia Orecochnonius niloticus in polyculture with catfish Heterobranchus
longifilis
871
Figures in a column followed by the same superscript are not significantly different.
SPECIFIC GROWTH RATE
The highest specific growth rate (SGR) was recorded in tilapia stocked with shooters
(1.14%). Tilapia in monoculture shows the least SGR. Significant difference (P<0.05) exit
between SGR of tilapia stocked with shooters and those in monoculture. There was however* no
significant difference (P>0.05) between tilapia in polyculture with shooters and those with non-
shooters and between tilapia stocked with non-shooters and the ones in monoculture.
3.2 FOOD CONVERSION EFFICIENCY
The FCE was generally lower for tilapia stocked with shooters, non-shooters and those in
monoculture (5.58, 5.70 and 6.30 respectively). The highest FCE was recorded for tilapia in
monoculture (6.3). This was not however significantly different (P<0.05) from those in polyculture.
3.3 DISCUSSION
The relatively low mean daily growth rate 1.2g/day of tilapia in monoculture agree with
low rates (0.8g/day, 0.6g/day) recorded in monocultures with T.zilli and T. nilotica respectively by
Dadzie (1982) and can be attribtued to the absence of predatory fish to check prolific breeding
habit of tilapia and reduce density. Also, the difference between daily growth rate of tilapia in
monoculture and those with "non-shooters" of H. longifilis was not significant (P>0.05). Properly
because the "non-shooters" could not mature fast enough to effectively prey upon tilapia before
they reproduce and increase density. The significantly higher (P<0.05) daily growth rate 2.6g/day
.of tilapia stocked with "shooters" of H. longifilis could be due to higher predatory potential of the
later to reduce density of tilapia populaiton. In a similar experiment, Hulata et al (1982) using
European and Chinese races of common carp established that highest densities gave least body
weights as a result of competition for space and food. The highest F.C.E (6.3%) recorded for
tilapia in monoculture in this study agrees with results of Maldonado et al (1979) Villarreal (1980)
and pastastico et al (1982) that fish reared in higher densities consumed less food and converted
far less efficiently spending greater energy on surfacing resulting in low.growth performance and
vice versa.
Ponds Species Stocking Initial Final Mean SpecifiC growth rate %
Rate of weight weight Daily
Tilapia ha (9) (9) weight
(g)
O. niloticus with 20,000 50.46 499.5 2.6 b 1.36 b
catfish (shooter)
O. niloticus with 20,000 50.4b 440.4 2.3 bc 1.23 bC
catfish (non-
shooters)
O. niloticus in 20,000 50.4b 246.9 c 1.2 0.93 cci
monoculture
4. CONCLUSION AND RECOMMENDAITON
Although tilapia in Polyculture performed better than in monoculture in all cases, in this
study, the mean growth rate depended on the predatory potential of fish co-stocked. Only tilapia
stocked with efficient predatory fish can effectively reduce tilapia densities and significantly
(Pe-0.05) improve the growth performance in ponds.
ACKNOWLEDGEMENT
The authors wish to thank the management of !BB College of Agriculture for the financial
at,:isistance.
REFERENCES
APHA '1985: Standard method for the Examination of water and waste water, 16' editiori
Washington D.C.
Balogon, A.M.; Ologbobo, A.D 1989: Growth performance and Nutrient utilization of
fingerlings Claris eariepinus fed row and cooked soyabean diets. AquacultureY
76.119-126.
Dazie, S; 1982: Species combination in the tilapia culture. Aquaculture vol. 27.295-299.
aaget, J; Litis, A; 1965: Poisson de cote d Ivoire (eaux douces et eaux samumtres) mem. InsL Fr
Afr. Noire No. 74. 385pp.
Ewa-Oboho I, O.: Enyenihi. U. K. 1998: Aquacuiture implications of growth variation in the
African Catfish: Heterobranchus. Longifilis reared under controlled conditions. J.: appl.
Ichthyol. 14. 000-000.
Hecht, T; Appelbuan, S; 1988: Observation on infraspecific aggression and sibling connibálisms
by larvae of,Clarias gariepinus under controlled conditiona J. zool London. 21.21-44:
HuHate, G; Moar, R; VVohlfarth, G: 1982: Effect of Crowding and availability of food on growth rate
in the European and Chinese races of common carp (Cyprinus Carpio). Fish Biol. 20 323-
327.
Le.genclre. M. 1986: seasonal changes in sexual maturity ara.-.1 fecundity, and HCG-induced
breeding of the catfish: Heterobranchus longifilis reared in Ebrie Lagoon (Ivory COast).
Aquaculture. 55, 201-213.
Production of Glades anquillaris (Madfis) fry and fingerlings under indoor and outdoor hacthery
conditions. KLR1 annual Report 1987.36-40PP.,
Maldonaido, R. C, Pagan-Front, FA; 1979: Evaluation of polyculture in plastic fish
ponds utilizing channel catfish (Icatalurus eunotatual and blue . tilipia
(Sarotheroidon aurea) fed with bird food. CARIB, Vol 14.36.
Paritastico, J. 13, Espegedara, C: Reyes, D: 1982: Report on the polyoulture of Serotherodoe
niloticus and prochilodus reticulates. KALIKASAN Vol. 11 245-254.
Primavera, J. H: Eldoni, A 1981: Effect of stocking combination on growth, Production and
survival of,Milk fish (chanos Chanos) forski and pawn (penas rnonociou) fpbriCus in
polyculi.urein Brackis water ponds. Aquaculture 23.59-72.
Soinpatte K., Pandian, T.J; 1976; Effect of density on food utilization and surfacing behaviOur in
the obligatory air-breathing fish (Channa Striatus). J. Sch. Bio./Sci. 10.11pp
-eugels G. F; 1982: preliminary results of a !Morphological study of five African species of the
subgenus Clariae. J. Nat. History 6. 439-464.
872
Teugles G. F., 1990: A systematic revision of the African Catfish Heterobranchus Geogray Saint
Hilade (1809) Pisces: Clariidae. Zool J. Liman Soc. 98:237-257.
Villareal Z. W., 1980: culture of tilapia and Cyorinus in fortaleza Bennales Pisco (Peru)
Documenta, Vol. 8, No. 74.
873


Effect of darting phenomenon of African catfish Heterobranchus longifilis (Burchell 1822) on growth performance of Nile tilapia: Oreochromis niloticus (Linnaeus, 1758)

Replicate Ponds of 0.02ha stocked at 500 catfishes with 20,000 tilapia/ha were used to assess growth performance of O.niloticus, average weight 50.4g with (i) darted catfish; H.longifilis (shooters) average weight 60.3g (ii) non-shooters of H.longifilis, average weight 35.4g. Final mean weight, mean growth rate, specific growth rate and food conversion ratio were 499.5g 26g/day, 1.36% and 5.58% respectively for O.niloticus stocked with longifilis (shooters and 440.4g 2.3g/day 1.23% and 5.58% respectively for O.niloticus stocked withH.longifilis (non- shooters) and 246.9g, 1.2g/day, 0.93, 6.30% respectively for tilapia in monoculture. The least growth was noted for O. niloticus in monoculture while the best growth was recorded O. niloticus in polyculture with darted catfis

EFFECT OF DARTING PHENOMENON OF AFRICAN CATFISH HETEROBRANCHUS
LONGIFILIS (13URCHELL, 1822) ON GROWTH PERFORMANCE OF NILE TILAPIA:
OREOCHNOMIS NILOTICUS (LINNAEUS, 1758).
B. OFEIVr, G. IKPI, A. AYOTUNDE.
DEPARTMENT OF FISHERIES, FACULTY OF AGRIC AND FORESTY, CRQSS-RI VER STATE
UNIVERSITY OF TECHNOLOGV OBUBRA C.R.S. NIGERIA
ABSTRACT
Replicate Ponds of 0.02ha stocked at 500 Catfish/ha with 20,000 tilapia/ha were used to.assess
growth performance of 0.niloticus. average weight 50.4g. with (i) darted catfish;
(shooters) average weight 60.3g (ii) .non-shooters of H. lengifilis Average weight 35 4g Final
mean weight, mean growth rate. specific growth rate and food conversion ratio were 499.5g
26g/clay. 1.36% and 5 58% respectively for 0 niloticus stocked with lon_gAls (shooters-and
440 4g 2 3g/day 1.23% and 5.58% respectively for O.nilticus stocked with H gifj (non
shooters) and 246.9g. 1.2g/day. 0.93. 6.30% respectively for Napa in monoculture. Theeleast
growth was noted for aniloticus in monoculture while the best growth was -recorded 0.nilet(O.US.:in
polyculture with darted catfish.
INTRODUCTION
Many fish farmers in.Nigerta:stock their ponis with.tilapia.0.monoculture, but sofletitres -
with African''catfish, although: tilaPia::JS.-always the locus of the enterprise in the cOuntry,
by man.y, and attraCts good.caSrt:,,iattid; the feeds are cheap and atfor0abié. The main prOWetif0
tilapia cUlture is-the early spawri.14.!:and rapid overpopulation in .ponds, w.hich leads to;:jkilited.
growth and -poor performance (D..a.dx. e, 1982). There is therefore need tO improve in the:.,S4Strn
especially if intended to capture more .market
The Polyculture of tilipia.,.:With .catfish is well docUmented (Madu et al. 1987: pastasircp et
al. 1982), In most of 'these culture'..:CatfiSh is used as predator§ to control Napa populatiOn and
Improve growth.
- -.1-
However, experiments have revealed low predatory performance of catfish in certain
stocks resulting in growth performance of tilapia that are not significantly (13-z0 05) different from
those of monocultures. (Taege in press)
The occurrence in African catfish of offspring's with high growth superiority (darting) over
individuas of same age bracket; with more aggressive sibling connibalisin have been reported
(Madu et al 1987: Ewa-Oboho, 1998). but no research had been carried out to assess the
performance of tilapia in polyculture with these fast growing (shooters') African catfish. This
research therefore attempts to isolate the fast growers of and to determine their effect on growth
performance of the nile tilapia (preechromis nilotocus).
METHODOLOGY
This study was carried out in the fish farm complex of the Institute of Oceanography
Univeisity of Calabar. Water source was a perennial reservoir and the experiment was performed
in a system with water flow of 2-3 Usec.
Matured breeders of Ft lenatilis and O. niletigus were collected from brood stock earthed
ponds and transferred to the indoor hatchery where they were sexeci and tested for ripeness as
described by Daget and I tis (1965) and teugels (1982. 1990).
0)
2.1 BREEDING OPERATION
Breeding of catfish (H. logifilis) was carried out by hypophysation according to the
method described by legendry (1986) using purified carp pituitary extract at a dose of 4g/kg body
weight. Fertilized eggs were incubated in water with flow-through rate 1-3 Lmin. Mean hatching
percentage was 80%.
2.2 LARVAL REARING AND GROWTH MONITORING
Hatchlings of H. longifilis were measured for total length and weight and distributed into
two 501 aquaria at dentisy of 18 larval/C and fed at 3% body weight (Ewa-Oboho etal 1998). Fry
were fed exclusively on live food (Zooplankton) within first 14 days (Hecht et al 1988) then later
with dry food in the form of crumbled non-pelletised feeds formulated according to,E3alogon and
Ologhobo (1989) with 40% protein.' Fast growing (darting ) fish were identified and removed
every 7 days.
2.3 'FATTENING OF FRY
The two types of fry (shooter§ and non-shooters) of H. lonqifilis were transferred
separately into outdoor tanks at density 15 larva/m2 fed diet of 40% crude protein at 5% body
weight thrice daily, supplemented with zooplankton. Fingerlings were harvested 6 svveeks later at
average weight; 35.4 and 60.3g for "non-shooter" and "shooter" respectively.
2.4 EXPERIMENT ON POLYCULTURE
Fast growing fingerlings (shooters) of H. longiflis (60.3g) and non-shooters (35.4g) were
separately stocked with mixed tilapia breeders (50.4g) in 0.02ha replicate ponds at density of
5000 catfish/ha with 20,000 tilapialha at 1:3 male: female sex ratio. Mixed sex tilapia in
monoculture at density 20,000 tilapia/ha and 1:3 r'-ale: female séx' ratio was the Control. Fish
were fed at 5% biomass with crumbled non-palletized feeds with 40% crude protein tvvice daily.
Twenty randomly selected fish were sampled for weight bs-weekly and at the end Of 168 day§
ponds were drained, total nuMbers and weight of fish noted. Physico-chemical parameters of
water used for all experiments were deterrhined according to standard methods (APHA, 1985)
and Presented in table 1. One-way analysis of variance (ANOVA) was used for all statistical
comparison of growth-indices.
3. RESULTS
3.1 GROWTH PERFORMANCE
Table 2 shows the growth performance of 0. niloticus in Payculture vvith "shooters" and
"non-shooters" of H. longifilis. The best perfOrrhance was recorded in 0.nilotiaCus stocked with
"shooters". The mean weight gained was-signifiCantly different (P<0.05) from O. niloticus in
monoculture. However, no significant difference (P< 0.05) exists between 0. niloticus in
polyculture with shooters and those with non-shooters and between tilapia in mOnoculture and'
those in Poiyoulture with non-shooters:- Tilapia in monoculture show the least growth
performance. (Table II)
331
TABLE 1:
Mean values of some physical and chernical,pararneters of water used for exppriments
Growthyonds
7.8
0:66-
8.0
.
25,8
TABLE 2:
Growth performance of tilapia Orecochnonius niloticus in polyculture with catfish
Hetp!ob ranshRtionaiti,Ii
_
5-0.46 499.5' I 2.6 1.3-61)
50.44 4404b Lt.", r 1 23
50.4b 246.9's 1.2 c 0.93
Figures in a column followed by the same superscript are not significantly different
SPECIFIC GROWTH RATE
The highest specific growth rate (SGR) was recorded in tilapia stocked with shooters
(1.14%) Tilapia in monoculture shows the least SGR. Significant difference (P<0 05) exit
between SGR of tilapia stocked with shooters and those in monoculture There was however no
significant difference (P>0.05) between tilapia in polyculture with shooters and those with non-
shooters and between tilapia stocked with non-shooters and the ones in monoculture.
3.2 FOOD CONVERSION EFFICIENCY
The [CE was generally lower for tilapia stocked:wiWshooters, non-shooters and those in
monoculture (5 58. 5.70 and 6.30 respectively). The highiSt FCE was reCorded for tilapia in
monoculture (6.3) This was not however significantly diffet0.(1P<O:05) from those in polyculture.
3 3 DISCUSSION
The leiatively low mean daily growth rate 1.2g/daY of tilapia in monoculture agree with
low rates (0 8gday, 0.6g/day) recorded in monocultures with T.zilli and T. nilotica respectively ,by
Dadzie (1982) and can be attribtued to the absence of predatory fish to check prolific breeding
habit of tilapia and reduce density. Also, the difference between daily growth rate of tilapia in
monoculture and those wrth -non-shooters" of H. langifilis was not significant (P>0.05). Properly
l),L:ause the non-shooters" could not mature fast enough to effectively prey upon tilapia before
h
-tey reproduce and increase density. The significantly higher (0<0.05) da.ily growth rate 2.6g/day
oftipa stocked with -shooters" of H. longifilis could be due to higher predatory potential of the
latcg to rediice density of tilapia populaiton. In a similar experiment, Hulata et al (1982) using
.
Fur,..pean and Cninese races of common carp established that highest densities gave least body:
wt,i ;hts LpF.-, a resillt of competition for space and food. The highest F.C.E (6 3%) recorded for
Parameters Aquaria Outdoor ponds
Dissolved Oxygen (mg/l) 6.8 7.0
Ammänjojmg/1) 0.04'
PH 7.5 8.8
28.0Temp. CC) -2-6.8
Ponds I oc ing Rate o Initial Final Mean Specific
Tilapia ha weight weight Daily growth
(9) (9) weight rate %
0. niloticus with 20,000
catfish (shooter)
2- . 0. nilotxus with 20,000
_catfish_(non7shooteris)
3 0 niloticus in 20,000
L._ L monoculture_
tilapia in monoculture in this study agrees with results of Maldonado et al (1979) Villarreal (1980)
and pastastico et al (1982) that fish reared in higher densities consumed less food and converted
far less efficiently spending greater energy on surfacing resulting in low growth performance and
vice versa.
4. CONCLUSION AND RECOMMENUAITON
Although tilapia in Polyculture performed better than in monoculture in all cases, in this
study, the mean growth rate depended on the predatory potential of fish co-stocked. Only tilapia
stocked with efficient predatory fish can effectively reduce tilapia densities and significantly
(P.(0.05) improve the growth performance in ponds.
ACKNOWLEDGEIVIENT
The authors wish to thank the management of !BB College of Agriculture for the financial
assistance.
REFERENCES
APHA 1985: Standard Methed for the Examination of water and wastewater, 16tn edition
Washington D.C. ,)',
Balogon, AM.; Ologbobo, A.p 1989: Growth performance and Nutrient utilization of .ringeriinge
Cleris gariepinus fed row and cooked soyabean diets. Aquaculture 76.119-126'.
. Dazie, S; 1982: Species cornbination in the tilapia culture. Aquaculture vol. 27.295-299.
Daget, J; Litis, A; 1965: Pois4On de cote d lvoire (eaux douces et eaux sarriurntres) rnern. Inst. Fr
Afr. Noire No, 74. 38,$pp.
Ewa-Obotio I. O.: Enyenihi. U.K. 1998: Aquaculture implications of growth variation in the Afric:an
Catfish: HeterobranchLis. Longifilis reared under controlled conditions. J. eppl. lchthyol.
14. 000-000.
Hecht, T; Appelbuan, S; 1988 .Observation on infraspecific, aggression aria eibiing connibaliems
by larvae of aeries gartepinus under controlled conditions J. zool London. 21.2144.
Hullata, G: Moar, R; Wohlfarth,i 0: 1982: Effect of Crowding and availability of food on growth rate
in the European and Chinese races of cernmon carp (penprinus Carpio). Fish Bici. 20 323-
327,
Legendre. M. 1986: seascinal changes in sexual maturity and feceindity, and HCC'e-induced
breeding of the catfish: Heterobranchus lio.ngifilis reared in Ebrie Lagoon (Ivory Coast).
Aquaculture. 55, 201-213.
Production of Clarias anquillarislMadfiel fry and fingerlings under indoor and outdoor hacthery
conditions. KLRI annual Report 1987.36-40pp,
Maldonaldo, R. C, Pegan-Front, FA; 1979: Evaluation of pelyculture in plastic; fi eh ;ponds utilizing
channel catfish (Icataluruseeurictatual and blue tilipia (Sprotherpcipn aurea) Pad with bird
food. CAPdB, Vol 14.36.
Fantastic°, J. B, Espegedara, C; Reyes, D: 1982: Report on the polyculture of Serotheredon
niloticus and prochilodus reticulates. KALIKASAN Vol. 11 245-25e,
Primavera, J H; Eldoni, A 1981: Effect of stocking combination on growth, Production z,;(-11
survival of Milk fish (canos 'Chanos) forski and pawn (pgagees monodon) iebricus
polyculture in Brackis water ponds. Aquaculture 23.59-72.
Sornpath, K Panchen, T.J; 1976: Effect of density on food utilization and surfacing behaviULIf in
the obligatory air-breathing fish (Channel Striatus). J. Sch. Bio./Sci. 10.11pp
Teugels G. F; 1982: preliminary results of a Morphological study of five African epecies of te
subgenus Clariae. J. Nat. History 6. 439-464.
333
Teugles G. F., 1990: A systematic revision of the African Catfish Heterobranchus Geogray Saint
Hilarie (1809) Pisces: Clariidae. Zool J. Liman Soc. 98:237-257.
Villareal Z. W., 1980: culture of tilapia and Cyprinus in fortaleza Bennales Pisco (Peru)
DOcumenta, Vol. 8, No. 74.
GROWTH RESPONSE AND SURVIVAL OF F1 HYBRID FRY OF HETEROBRANCHUS
LONGIFILIS AND CLARlAS GARIEPlAlUS REARED IN GLASS AQUARIA AND PLASTIC
BASINS
BY
NLEWADIM, A. A. AND MADU, O. C.
Fisheries Department, Michael Okpara University of Agriculture, Umudike,
P. M. B. 7267, Umuahia, Abia State.
The growth response of F1 hybrid fry of female Heterobranchus longifilis and male Ciarías
gariepinus were investigated under laboratory conditions in glass aquana glass tanks and plastic
basins. The larvae were' produced artificially after inducement with Ovaprim. The hatching
percentage was very high. Weekly mean length and weight were monitored for 6 weeks. The
average length increase was higher in aquaria glass tanks than in plastic basin. However, there
wet-e depressed and irregular weight increases in both types of rearing troughs while significant
weight increase (p < 0.05) was recorded at week 6 in the plastic basin. Generally, the growth
rate and survival in both containers were not significantly different
OCLICTION.
The breeding goal of any aquaculture programme should be to adopt methods that will
produce quality seed which can survive better, grow faster and resist some routine or common
diseases and adverse environmental conditions. Fish hybridization seems to achieve optimum
culture characters from different species as a result of heterosis (Hickling, 1966; Moav, 1979;
334


Effect of darting phenomenon of African catfish Heterobranchus longifilis (Burchell 1822) on growth performance of Nile tilapia: Oreochromis niloticus (Linnaeus, 1758)

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