Haematology and gonad histology of Oreochromis niloticus (Linnaeus, 1758) fed Carica papaya seed meal

This research investigated the effect of Pawpaw (Carica papaya) seed meal (PSM) on haematological parameters and gonad histology of Oreochromis niloticus (Linnaeus, 1758). Freshly hatched fry of O. niloticus were fed blended commercial diet (35%CP) mixed with varying levels of PSM (0, 2, 4, 6 and 8gkg-1) for 28days in fifteen aquarium tanks (30×30×20cm3). Resultant fingerlings were maintained in outdoor concrete tanks (1×1×1m3) for 140days till they gained an average weight of 30g. Haematological analysis and gonad histology was done to determent the effect of the PSM on the fish. Haematological changes observed in this study did not revealed detrimental effect of feeding of PSM. However, histological evaluation of the gonads showed various degrees of deformities and tends to increase in severity as the levels of PMS increased. It was concluded that PSM might not affect the health status of the Nile tilapia but lead to sterility of the fish

UJECAJ OBNAVLJANJA VODE NA RAST MLAĐI Clarius gariepinus

The aim of this study was to determine the effect of different water change frequency on the growth of African catfish Clarias gariepinus. Fingerlings with initial mean weights of 7.02 ± 0.05g were stocked (50 fish each) in fifteen concrete tanks (2x2x2m) and were conditioned under five different treatments of water renewal, namely: TRT1 (no water change), TRT2 (water renewed daily), TRT3 (water renewed after four days), TRT4 (water renewed after eight days) and TRT5 (water renewed after fourteen days). After 56 days of feeding, results revealed best growth performance of fingerlings in tanks with water renewal frequency of TRT3 and TRT4. Similarly, survival was higher in these frequencies compared to the others; the control treatment, however, had the least performance for all parameters measured. It is therefore recommended that water renewal should be done once between four and eight days to enhance growth of African catfish fingerlings reared in a static system.Cilj ovog istraživanja je utvrditi utjecaj različitih frekvencija promjene vode na rast afričkog soma, Clarius gariepinus. Mlađ s početnim srednjim težinama od 7,02 ± 0,05 g je bila smještena (po 50 riba u svaki) u petnaest betonskih spremnika (2x2x2 m) koji su tretirani s pet različitih tretmana obnavljanja vode i to: TRT1 (bez promjene vode), TRT2 (dnevna promjena vode), TRT3 (voda se obnavljala nakon četiri dana), TRT4 (voda se obnavljala nakon osam dana) i TRT5 (voda se obnavljala nakon četrnaest dana). Nakon 56 dana hranjenja, najbolje rezultate rasta je pokazala mlađ u spremnicima s frekvencijom obnavljanja vode od TRT3 i TRT4. Slično tome, preživljavanje je bilo više u tim frekvencijama u usporedbi s ostalima. Međutim, kontrolni tretman je imao najmanji učinak za sve mjerene parametre. Stoga se preporučuje da se radi obnova vode nakon četiri do osam dana kako bi se poboljšalo rast mlađi afričkih somova uzgojenih u statičkom sustavu

CANNIBALISM AND PERFORMANCE EVALUATION OF HYBRIDS BETWEEN Clarias batrachus AND Clarias gariepinus

Kanibalizam je važna karakteristika afričkog soma koji je značajno smanjio broj uzgojenih riba u ribnjačarstvima. Ova studija procjenjuje učinak uzajamne hibridizacije Clarius batrachus i Clarius gariepinus na kanibalizam i brzinu rasta njihovih potomaka u zatvorenom uzgojnom sustavu. Dobiveni rezultat ukazuje na odličnu performansu rasta hibrida C. gariepinus ♂ i C. batrachus ♀ u odnosu na izvorne vrste. Međutim, recipročni hibridi između C. gariepinus ♀ i C. batrachus ♂ ugibaju nekoliko sati nakon izlijeganja. Kanibalizam je značajno smanjen križanjem C. gariepinus ♂ i C. batrachus ♀, sa 100%-tnim preživljavanjem nakon pet mjeseci uzgoja. Dakle, to bi moglo koristiti uzgajivačima ribe pri komercijalnom uzgoju afričkog soma za smanjenje kanibalizma i povećanje uzgoja.Cannibalism is an important characteristic of African catfish that significantly reduces the number of stocked fish at harvest. This study evaluates the effect of reciprocal hybridization of Clarias batrachus and Clarias gariepinus on cannibalism and growth performance of their progenies in an indoor rearing system. The result obtained reveals excellent performance of hybrids of C. gariepinus ♂ and C. batrachus ♀ over the purebreds in terms of growth. However, the reciprocal hybrids between C. gariepinus ♀ and C. batrachus ♂all died few hours after hatching. Cannibalism was significantly reduced in the crosses between C. gariepinus ♂ and C. batrachus ♀ with 100% survival after five months of culture. Hence, this could be exploited in commercial production of catfish to reduce cannibalism and increase harvest size of fish farmer

UČINCI UVJETA SKLADIŠTENJA NA ODLIKE KVALITETE KOMERCIJALNE RIBLJE HRANE I RASTA AFRIČKOG SOMA Clarius gariepinus

This study was conducted to determine the effect of storage conditions on the quality of feed and the aftermath effect of feeding fish with such feeds. Three commercial diets used for this study included Coppens®, Multifeed® and Vital feed®. Feed was stored either by opening the bag to the atmosphere (WO), the bag opened with neck tied using a rubber ring to prevent exposure to the atmosphere (OT) or sealed (SC) until the start of the feeding trials. The feed was stored under these conditions for six months. Nutrient analyses revealed significant changes in feeds held under the WO condition when compared with other storage conditions. Nutritive changes also varied with commercial feed type. Mould infestation of the feed was noticeable more in the WO condition of storage compared to the SC condition. After feeding C. gariepinus for fifty-six days, lesions were observed on fish fed mouldy feed held under the WO condition, which led to mass mortalities. Growth performance was higher in all fish fed SC stored feed, and for those fed Coppens® and Multifeed® under OT storage conditions. It is advised that storage of fish feeds up to six months should be undertaken with considerable care and attention.Istraživanje je provedeno kako bi se utvrdio utjecaj uvjeta skladištenja na kakvoću hrane i posljedica učinka hranidbe ribe s takvom hranom. Tri komercijalna hranjiva su korištena u ovom istraživanju su: Coppens®, Multifeed® i Vital feed ®. Hrana je uskladištena: otvaranjem vreća u atmosferu (WO), otvaranjem vreća vezanih gumenim prstenom kako bi se spriječilo izlaganje atmosferi (OT) ili hermetički zatvorene vreće (SC) do početka hranjenja. Hrana je pohranjena u tim uvjetima tijekom šest mjeseci. Analiza hranjiva pokazala je značajne promjene u hrani koja se održava u WO stanju u usporedbi s drugim uvjetima skladištenja. Nutritivne promjene također su varirale s vrstom komercijalne hrane. Pojava plijesni na hrani je bila primjetno viša u WO uvjetima čuvanja u odnosu na SC uvijete. Nakon hranjenja C. gariepinus tijekom pedeset i šest dana, uočene su lezije na ribi koja je hranjena pljesnivom hranom, koja se skladištila pod WO uvjetima, što je dovelo do masovnih uginuća. Karakteristike rasta su bile veće kod svih riba hranjenih u SC uvjetima pohranjene hrane, kao i za one hranjene Coppens® i Multifeed® pod uvjetima COT skladištenja. Preporučljivo je da se skladištenju riblje hrane do šest mjeseci treba posvetiti znatnu brigu i pažnju

EFFECTS OF TANK BACKGROUND COLOUR ON GROWTH PERFORMANCE AND FEED UTILIZATION OF AFRICAN CATFISH Clarias gariepinus (Burchell, 1822) FINGERLINGS

U ovom radu istraživana je brzina rasta mlađi Clarius gariepinus (Burchell, 1822) uzgajanih u bijelim, zelenim, plavim, crnim i crvenim bazenima. Svaka boja testirana je na triplikatu 1 m3 bazenu s početnom gustoćom mlađi od 100 jedinki po bazenu (1,07 g). Ribe su dnevno hranjene komercijalnom hranom na 5% tjelesne težine tijekom osam tjedana. Težina ribe je mjerena svaka 2 tjedna kako bi se prilagodila stopa ishrane. Boja bazena imala je značajan utjecaj (P <0,05) na ukupne performanse mlađi. Uzgoj u crnim bazenima rezultirao je većim dnevnim unosom hrane (0,44 g) i boljom performansom rasta u usporedbi s drugim bojama bazena, dok je najslabiji rast zabilježen u plavim i zelenim bazenima. Kretanje proteina i masti kroz osam tjedana imalo je sličan trend kao i rast. Također, testovi glukoze u serumu za koju se smatra da je pokazatelj stresa pokazali su veću razinu u svijetloj pozadini bazena. Na postotak preživljavanja boja bazena nije utjecala. Zaključeno je da su bazeni tamne boje, poput crne ili crvene, bolji u odnosu na svijetlo obojene bazene za uzgoj mlađi afričkog soma.The performance of Clarias gariepinus (Burchell, 1822) fingerlings reared in white, green, blue, black and red coloured tanks was investigated. Each colour was tested in triplicate 1 m3 tanks with an initial stocking density of 100 fingerlings per tank (1.07 g). Fish were fed a commercial diet at 5% body weight per day for eight weeks. Fish weights were sampled every 2 weeks to adjust feeding rates. Tank colour had a significant effect (P < 0.05) on the overall performance of the fingerlings. Rearing in black tanks resulted in a higher daily feed intake (0.44 g) and better growth performance when compared to other tank colours, while the poorest performance was observed in blue and green tanks. Carcass protein and fat content at 8 weeks revealed a trend similar to that observed for growth. Also, serum glucose tests showed higher levels in light background tanks and were thought to be an indication of stress. Survival was not affected by tank colour. It was concluded that dark-coloured tanks such as black or red were better in comparison to light-coloured tanks for the rearing of African catfish fingerlings

EFFECTS OF TANK BACKGROUND COLOUR ON GROWTH PERFORMANCE AND FEED UTILIZATION OF AFRICAN CATFISH Clarias gariepinus (Burchell, 1822) FINGERLINGS

U ovom radu istraživana je brzina rasta mlađi Clarius gariepinus (Burchell, 1822) uzgajanih u bijelim, zelenim, plavim, crnim i crvenim bazenima. Svaka boja testirana je na triplikatu 1 m3 bazenu s početnom gustoćom mlađi od 100 jedinki po bazenu (1,07 g). Ribe su dnevno hranjene komercijalnom hranom na 5% tjelesne težine tijekom osam tjedana. Težina ribe je mjerena svaka 2 tjedna kako bi se prilagodila stopa ishrane. Boja bazena imala je značajan utjecaj (P <0,05) na ukupne performanse mlađi. Uzgoj u crnim bazenima rezultirao je većim dnevnim unosom hrane (0,44 g) i boljom performansom rasta u usporedbi s drugim bojama bazena, dok je najslabiji rast zabilježen u plavim i zelenim bazenima. Kretanje proteina i masti kroz osam tjedana imalo je sličan trend kao i rast. Također, testovi glukoze u serumu za koju se smatra da je pokazatelj stresa pokazali su veću razinu u svijetloj pozadini bazena. Na postotak preživljavanja boja bazena nije utjecala. Zaključeno je da su bazeni tamne boje, poput crne ili crvene, bolji u odnosu na svijetlo obojene bazene za uzgoj mlađi afričkog soma.The performance of Clarias gariepinus (Burchell, 1822) fingerlings reared in white, green, blue, black and red coloured tanks was investigated. Each colour was tested in triplicate 1 m3 tanks with an initial stocking density of 100 fingerlings per tank (1.07 g). Fish were fed a commercial diet at 5% body weight per day for eight weeks. Fish weights were sampled every 2 weeks to adjust feeding rates. Tank colour had a significant effect (P < 0.05) on the overall performance of the fingerlings. Rearing in black tanks resulted in a higher daily feed intake (0.44 g) and better growth performance when compared to other tank colours, while the poorest performance was observed in blue and green tanks. Carcass protein and fat content at 8 weeks revealed a trend similar to that observed for growth. Also, serum glucose tests showed higher levels in light background tanks and were thought to be an indication of stress. Survival was not affected by tank colour. It was concluded that dark-coloured tanks such as black or red were better in comparison to light-coloured tanks for the rearing of African catfish fingerlings

ODNOS IZMEĐU KOMBINACIJE MASE MATIČNOG STOKA I USPJEŠNOSTI MRIJESTA AFRIČKOG SOMA (Clarias gariepinus)

Pearson\u27s correlation and regression analysis were used in this study to test the relationship between broodstock weight combination and broodstock characteristics for African catfish (Clarias gariepinus) such as fecundity, weight of egg, weight of testis and their relationship with breeding parameters such as fertilization and hatchability. The result obtained reveals that broodstock size correlated positively with fecundity, weight of egg and weight of testis. Though the same strong relationship was observed for fertilization and hatchability, low r2 values were obtained in regression analysis between these parameters, suggesting an insignificant regression. Fecundity also correlated positively with fertilization (0.764) and hatchability (0.494). The regression between fecundity and weight of female was significant (r2 = 0.9558). Multiple regression showed significant regressions between % Fertilization and Fecundity, Egg Weight and Weight of Testis as a whole, between % Fertilization and Weight of Male and Weight of Female and between % Hatchability and Fecundity, Egg Weight, Weight of Testis and % Fertilization. The present study therefore advanced the thought that larger African catfish broodstocks are better for breeding activities.U ovom istraživanju korištena je Pearsonova korelacijska i regresijska analiza za ispitivanje odnosa kombinacije mase matičnog stoka i osobina matičnog stoka afričkog soma (Clarias gariepinus) kao što su: plodnost, masa jaja, masa testisa i njihov odnos s uzgojnim parametrima, oplodnjom i valjenjem. Dobiveni rezultat otkriva pozitivnu korelaciju matičnog stoka s plodnošću, masom jaja i masom testisa. Iako je podjednako jak odnos zabilježen za oplodnju i valjenje, dobivene su niske r2 vrijednosti u regresijskoj analizi navedenih parametara, označavajući neznatnu regresiju. Plodnost je također u pozitivnoj korelaciji s oplodnjom (0,764) i valjenjem (0,494). Regresija između plodnosti i mase ženke je značajna (r2 = 0,9558). Višestruka regresija pokazala je značajne regresije između postotka oplodnje i plodnosti, mase jajeta i mase testisa kao cjeline, zatim između postotka oplodnje i mase mužjaka te mase ženke, a također i između postotka valjenja i plodnosti, mase jajeta, mase testisa i postotka oplodnje. Ovo istraživanje dokazalo je da veći matični stok afričkog soma pozitivno utječe na uzgojne aktivnosti

Effect of Various Levels of Raw Citrullus lanatus Seed Meal Diets on Growth Performance of Cyprinus carpio Fingerlings

Abstract The nutritional value of feeding Cyprinus carpio various levels of raw watermelon seed meal was evaluated in this study. Five diets of 35% crude protein were formulated with different levels of raw seed meal at 0%, 5%, 10%, 15% and 20% inclusion. Twenty fingerlings were randomly allocated in triplicate for each treatment in 70 liters plastic bowls, aeration was provided to culture bowls throughout the 12-week trial period. The results revealed that the inclusion level of 10% raw watermelon seed meal in the diet gave the best mean weight gain, feed conversion ratio, feed conversion efficiency, protein efficiency ratio, apparent net protein utilization, specific growth rate and survival rate. The growth performance decreased with increasing the inclusion level of raw seed meal beyond 10% (P&lt;0.05). The inclusion level of 10% raw watermelon seed meal in the diet of common carp is found to be ideal for enhancing growth and better nutrient utilization

Optimization of the cytogenetic protocol for Pangasianodon hypophthalmus (Sauvage, 1878) and Clarias gariepinus (Burchell, 1822)

To obtain well spread chromosomes, the cytogenetic protocol for Pangasianodon hypophthalmus and Clarias gariepinus were optimized. This includes, the colchicine concentration (0.01%, 0.025%, 0.05%)/exposure duration (1, 3, and 5 h), hypotonic solution (distilled water or 0.075M KCl solution)/exposure duration (30 min, 1, and 2 h), the time of cell suspension preparation (at hypotonic treatment or before slide preparation) and chromosome aging period (0, 3, and 7 days in Carnoy’s fixative). In addition, the type (i.e., fin, gill or kidney) and the amount of tissue (10, 50, 100 or 150 mg) were also investigated. Regardless of the species, the result obtained showed that well-spread chromosomes could be obtained using the following optimized protocol: Juveniles are injected with 0.05% colchicine (at one ml kg−1) and allowed to swim for 3 h. Then, 50 mg of gill tissue is made into cell suspension in 0.075M KCl for 1 h. The cell suspension is treated in Carnoy’s fixative (changed three times at 20 min interval) and then aged for 3 days. Finally, chromosome slides are made and stained with 10% Giemsa for 1 h