MACROZOOBENTHOS IN CARP FISH FRY

Kvalitativni i kvantitativni sastav makrozoobentosa i kemizam vode istraživani su u 6 ribnjaka, pojedinačne veličine 8-10 ha-1, na ribnjačarstvu »Donji Miholjac«. Istraživani su ribnjaci bili nasađeni s 200 000 ind•ha-1 trodnevnih ličinki šarana. Mlađ je u tijeku uzgojne sezone prihranjivan životinjskim bjelančevinama. Kvalitativni i kvantitativni sastav makrozoobentosa formirao se uglavnom na račun sistematskih skupina Oligochaeta i Chironomidae. Prosječna količina Oligochaeta varirala je u pojedinim ribnjacima od 119 do 944 ind•m-2 od 2,18 do 14,09 g.m-2, a ličinki Chironomidae od 174 do 1 086 ind•m-2 i od 2,66 do 14,09 g.m-2. Variranje ukupnog makrozoobentosa bilo je unutar amplitude do 28 do 5 805 ind•m-2 i od 0,11 do 73,72 g.m-2. U sredini ljeta utvrđen je nagli pad količine makrozoobentosa u svim ribnjacima (tabl. 1-6).Qualitative and quantitative components of macrozoobenthos was investigated on six fish farms with 8-10 ha-1 each at "Donji Miholjac". The ponds were stocked with 200,000 individuals per ha! of three-day-old carp larvae. The fry were fed with animal protein throughout the culturing season. The qualitative and quabtitative macrozoobenthos components formed mainly due to systematic groups of Oligochaeta and Chironomidae. The average size of Oligohaeta varied in each pond from 119 to 944 individuals per m-2 and from 2.18 to 14.09 g per m-2, and the larvae of Chironomidae from 174 to 1086 ind. per m-2 and from 2.66 to 14.09 g per m-2. Variation s of the total macrozoobenthos was within the amplitude of from 28 to 5805 ind. per m-2 and from 0.11 to 73.72 g. per m-2. In mid summer it was determined that there was a fall in the amount of macrozoobenthos in all fish ponds (Table 6)

ECONOMIC FEASABILITY OF CULTURE OF CONSUMPTION FISH UNDER DIFFERENT FEEDING CONDITIONS

U pokusnim ribnjacima pojedinačne veličine 0,1•ha-1 u ribnjačarstvu „Draganići“ istražena je ekonomska opravdanost uzgoja konzumnog šarana u polikulturi s ribama biljojedima (b. glavaš, s. glavaš, b. amur). Gustoća je nasada iznosila 3.250 ind.ha-1 ukupno jednogodišnjega ribljeg mlađa, i to: šarana 77% i biljojeda 23%. Istraživalo se tijekom uzgojne sezone od 25. travnja do 4. listopada 1990. Istražena su tri tretmana: I - prihranjivanje šarana žitaricama, bez gnojidbe ribnjaka, II - prihranjivanje riba žitaricama uz gnojidbu ribnjaka mineralnim gnojivom NPK formulacije 17:8:9 s ukupnom količinom 400 kg. ha-1 i III - prihranjivanje šarana industrijskim briketima s 20% životinjskih proteina. Iz rezultata istraživanja vidi se da su tretmani II i III pozitivno djelovali na priraste i prinose svih vrsta riba u polikulturi. Najbolji je ekonomski rezultat postignut u tretmanu II u kojem je šaran prihranjivan žitaricama. U toj je varijanti postignuta najveća ekonomičnost proizvodnje, akumulacije i dobit. Najveći ukupni prihod postignut je u III. varijanti uz prihranjivanje bjelančevinama. Rezultati istraživanja upućuju na povoljnu primjenu životinjskih proteina u prehrani konzumnog šarana, uz pravilan izbor polikulture i gustoće nasada.In experimental ponds of individual sizes 0.1 ha-1 the fish farm Draganići, the economic feasibility of the culture of consumption carp fish in poli culture with herbivorous fish was investigated (Hypophthalmichthys, molitrix, Val. Aristichthys nobilis Rich. Ctenopharyngodon idella Val.). The stock density was 3250 ind.ha-1of total one year old fish: carp 77%, herbivorous 23%. Investiga- tions were investigations were carried out during the culturing season, from 25 April to 4 October 1990. Thre treatments were investigated: I - feeding the carp with grains, without fertilizig the pond, II - feeding the fish with grains and fertilizing the pond with mineral fertilizer NPK of the formula 17:8:9 with the total quantity of 400 kg.ha-1, and III - feeding the carp with industrial brickets with 20% animal protein. The results show that treatments II and III had appositive affect on the growth and amount of all species of fish in poli culture. The most favorable economic result was reached with treatment II where the carp were fed with grains. The fish treated in this variation reached the highest economic production, accumulation and gain. The highest total gain was reached in the III variation along with supplement protein feeding. The result of investigations showed a satisfactory application of animal proteins in food of consumption carp, along with the proper choice of polyculture and stock density

BREEDING OF ONE YEAR OLD CARP FRY IN VARIED SETTING DENSITY

Istraživanja su se provela u dvije inačice pokusnih ribnjaka pojedinačne veličine 1ha-1 na ribnjačarstvu »Draganići«. U pokusnim se ribnjacima uzgajao šaranski mlađ od dobi 45 dana do dobi 4 mjeseca u dvije gustoće nasada: 30.000 ind. ha-1 (I) i 60.000 ind. ha-1 (II). Šaranski mlađ (Cyprinus carpio L.) uzgajao se je u polikulturi sa 5.000 ind. ha-1 b. glavaša (Hypophthalmichthys molitrix Val.) i 10.000 ind. ha-1 b. amura (Ctenopharingodon idella Val.). Tijekom uzgojne sezone (82 dana) istražilo se je hidrokemijsko i hidrobiološko stanje te ihtioprodukcija (prinosi i prirasti riba, prosj. ind. masa riba, hranidbeni koeficijent, Fultonov i Klarkov koeficijent kondicije). U kemizmu vode utvrđena je povremena tendencija pada količine kisika ispod razine 50% saturacije. Utvrđene su određene razlike u količini ukupnog zooplanktona (745±67 ind. l-1 - varijanta I i 497±53 ind. l-1 - varijanta II) i makrozoobentosa (9,48±1,36 g m-2 - varijanta I i 5,72±0,05 g m-2 - varijanta II), ali one nisu signifikantne (p>0,05 i p>0,01). Prirast šaranskoga mlađa u manjoj gustoći nasada iznosio je 918,8 kg ha-1 , a u većoj gustoći nasada 1.123,3 kg ha-1 , a prosječna ind. masa šarana u manjoj gustoći nasada 44 g i u većoj gustoći nasada 29,5 g. Preživljavanje šarana iznosilo je 73% (var. I) i 67% (var. II). Hranidbeni koeficijent u objema varijantama bio je oko 1, Fultonov koeficijent kondicije u objema varijantama oko 4, a Klarkov koeficijent kondicije oko 3. Ukupni prirast riba povećao se je na račun riba biljoždera u polikulturi za 440 kg ha-1 u varijanti I i za 413 kg ha-1 u varijanti II.The research was carried out on the fish-farm »Draganići« during the breeding season of the year 1993 (from 19th July to 13th November). In two variants (four exprerimental fish-ponds of 1 ha each) 40 days old carp fry of average individual masa of 0.0009 kg were bred in two setting densities: 30,000 ind. ha -1 (variant I) and 60,000 ind. ha-1 (variant II) in policulture with one month old fry of silver carp (5,000 ind. ha-1 ) and one month old fry of grass carp (10,000 ind. ha-1 ). Throughout the breeding season the research included observations of ecological factors (water chemism, zooplankton quantity, macrozoobenthos quantity) and of ichthyoproduction (yield growth, survival rate of fish, average individual mass of fish, Klark’s condition coefficient, Fulton’s condition coefficient and feeding coefficient). The research results show that all fish-ponds had similar water chemism. Average zooplankton quantity was in variant I 581 ind. l-1 , and in variant II 501 ind. l-1 while the average quantity of macrozoobenthos was 9.49 g m-2 in variant I, and 5.7 g m-2 in variant II. In the carp setting density of 30,000 ind. ha-1 the average survival rate of carp fry was 72.54%, and the average growth of carp was 919.1 kg ha–1 with an average individual mass of 0.044 kg. Klark’s condition coefficient was 3.18±0.02, Fulton’s condidion coefficient was 4.04±0.02 and feeding coefficient was 1.045. With the carp fry setting density of 60,000 ind. ha-1 the survival rate of carp was 66.75%, total growth was 1150.6 kg ha-1 with an average individual mass of 0.0295 kg. Klark’s condition coefficient was 3.32±0.02, Fulton’s condition coefficient was 4.21±0.03 and the feeding coefficient was 1.09. The above presented research results show that in these breeding conditions the setting of carp increased by 100% resulted in a 24.5% greater total growth of carp, but with a 49% smaller individual mass of carp with similar results in other fish farming indicators

SOME HEMATOLOGICAL VALUES OF TWO-YEAR OLD CARP (Cyprinus carpio L.)

Istraženo je djelovanje različitih tehnologija (I - bez gnojidbe, prihranjivanje riba žitaricama, II - gnojidba, prihranjivanje riba žitaricama i III - bez gnojidbe, prihranjivanje riba briketima s 20% životinjskih proteina) u uzgoju šarana u polikulturi s bijelim i sivim glavašem i bijelim amurom na neke hematološke pokazatelje (hematokrit, koncentracija hemoglobina, srednja koncentracija boje, ukupni proteini i ukupni lipidi). Gustoća je nasada bila 3.250 ind˙ha-1, a od toga šaran s 2.500 ind˙ha-1 (772). Prosječna vrijednost hemoglobina u krvnom serumu šarana bila je u kontrolnoj varijanti I 111,80±18,38 gr1, u varijanti II s gnojidbom mineralnim gnojivom NPK (17: 8: 9) i prihranjivanjem žitaricama 121,60±15,86, a u varijanti III bez gnojidbe i uz prihranjivanje briketima s 20% proteina 122,00±15,61 g˙l-1. Vrijednost je hematokrita iznosila pripadajuće 0,25±O,03, O,30±0,03 i O,28±0,00 L˙L-1, te srednja koncentracija boje 0,23±0,01, 0,23±O,01 i O,25±0,01 L˙L-1. Prosječna količina ukupnih proteina u krvnom serumu šarana iznosila je 27,OO±O,32 (varijanta I), 32,00±0,52 (varijanta II) i 34,00±1,02 (varijanta III). Prosječna vrijednost ukupnih lipida u krvnom serumu šarana bila je 1O,10±O,29 gr1 (varijanta I), 11,20±1,60 g˙l-1 (varijanta II) i l1,20±1,60 g˙l-1 (varijanta III). Statistički opravdane razlike utvrđene su samo u količini ukupnih proteina u serumu šarana (P>0,05), i to u korist varijante III u kojoj je šaran prihranjivan bjelančevinama životinjskog porijekla.An investigation was carried out in three variants of experimental fish ponds in which different technologies were applied (l - without fertilizing, feeding of carp with cereals; II - fertilizing, feeding of carp with cereals; III - without fertilizing, feeding of carp with pellets containing 20% of protein). Carp was reared under conditions of policulture with total stock density 3250 ind. ha-1 (2500 ind•ha-1 carp 250 ind•ha-1 silver carp, 250 ind•ha-1 bighead and 250 ind•ha-1 grass carp. Average weights of fishes were from 29 to 77 g. The values of some hematological and biochemical indices of carp were estimated (hematocrit, hemoglobin, MCHC, total protein and total lipids). The mean value of concentration of hemoglobin was 111,80±18,38 gl-1 (variant I); 121,60±15,86 gl-1 (variant II) and 122,00±15,61 gl-1 (variant III). Hematocrit value was 0,25±0,03 L˙L-1 0,30±0,03 L˙L-1 0,28±0,02 L˙L-1, and MCHC 0,23±0,01 L˙L-1; 0,23±0,01 L˙L-1; 0,25±0,01 L˙L-1 resp. The concentration of total protein in blood plasma of carp was 27,00±0,32 g˙L-1 (variant 1), 32,00±0,52 g˙L-1 (variant II) and 34,00±1,02 g˙L-1 (variant III). The concentration oftotallipids was 10,1O±0,29 g˙L-1,11,20±1,60 g˙L-1 and 1l,20±1,60 g˙L-1 resp. The differences between means values of these indices found in carp of different variants were significant (P>0.05) only for values of total protein (table 3) in variant III where carp was fed with protein of animal origin

THE CHANGE OF WATER CHEMISM IN CARP POUNDS

Istraživanja su provedena u ribnjačarstvu »Draganići« u pokusnim ribnjacima pojedinačne veličine 0,1 ha-1 i dubine oko 1 m. Tijekom uzgojne sezone godine 1991. istraženo je djelovanje mineralnog gnojiva NPK (12:12:12) i prihranjivanje riba bjelančevinastim briketima (»Gloria«) na kemizam vode u pokusnim ribnjacima. Utvrđene su određene razlike u količini 02, NH4+, N03-, P043- i potrošku KMn04 među pojedinim varijantama različito tretiranih ribnjaka idotočnom vodom potoka Stojnica (tabl, 1., 2.-6.), te znatne oscilacije svih kemijskih pokazatelja u tijeku uzgojne sezone. Prosječna količina 02 u pojedinim varijantama ribnjaka smanjila se u odnosu na dotočnu vodu od 5% do 13%, a količina N03- od 24% do 43%. Potrošak KMn04 povećao se je u usporedbi s dotočnom vodom od 6% do 22%. Smanjenje 02 i N03- te povećanje potroška KMn04 u pokusnim ribnjacima nije bilo signifikantno (P>O,05). Količina NH4+ i P043- povećala se u svim varijantama pokusnih ribnjaka od 36% do 82% i od 49% do 113% pripadajuće, u usporedbi s dotočnom vodom. Razlike su signifikantne (P<0,05). Utvrđene razlike o količini pojedinih kemijskih parametara u varijantama II. i III. u usporedbi s kontrolnom varijantom 1. bile su signifikantne (P>O,05) samo za količinu NH4+ i P043-.The researches has been conducted in the test ponds of fishfarming „Draganići“ each of them O.25 ackres great and 1 meter deep. During the breeding season of 1991, there have been examined the effect of mineral fertilizers NPK (12: 12: 12) and the reinforced nutrition of the fish with the protein briquettes (»Gloria«) on the chemism in the test ponds. During the breeding season, there have been stated certain differences in the quantity of the 02, NH4+, NO-, P043- and the outgoings of KMn04 among the separate variants of the treated ponds and the inflow water of the brook Stojnica (Tables 1, 2-6) and also the significant oscillations of all chemical indicators. The average quantity of 02 in the separate pond variants has reduced between 5% and 13% in relation to inflow water and the quantity of N03- between 24% and 43%. The outgoings of KMn04 has increased between 6% and 22% as compared with the inflow water. The reduction of 02 and N03- and the incensement of outgoings of KMn04 in the test ponds has not been significant (P 05). The quantity of NH4+ and P043- has increased between 36% and 82% and between 49% and 113% in all variants of test ponds respectively as compared with the inflow water. The differences are significant (PO. 05). The asserted differences about the quality of separate chemical parameters in the variants II. and III. as compared with the control variant I. has been significant (PO. 05) only for the quantity of NH4+ and P043-

THE INFLUENCE OF DIFFERENT FOOD ON THE PRODUCTION OF MARKET CARP (Cyprinus carpio L.)

Istraživalo se je na ribnjačarstvu »Draganići« tijekom uzgojne sezone god. 1990., u 8 pokusnih ribnjaka pojedinačne veličine 0,1 ha-1. Uzgajao se konzumni šaran u polikulturi s bijelim i sivim glavašem i bijelim amurom, s ukupnom količinom nasađenih riba 3.250 ind×h-1 (77% šarana, 23% biljojedi). Istraženo je djelovanje gnojidbe i različitog prihranjivanja na ribe s obzirom na: prinos i prirast ribe, individualnu masu riba, gubitke, hranidbeni koeficijent, Fultonov i Klarkov koeficijent uhranjenosti. Istražilo se i biokemijsko stanje u pojedinim ribnjacima. Utvrđena su jaka osciliranja pojedinih biokemijskih parametara u tijeku uzgojne sezone, napose količine kisika čije su vrijednosti povremeno bile ispod poželjne razine. Ukupni prirast riba iznosio je u prosjeku 703 kg ha-1 (kontrola bez gnojidbe, prihranjivanje riba žitaricama), 1.302 kg ha-1 (gnojidba, prihranjivanje riba žitaricama) i 2.573 kg ha-1 (bez gnojidbe, prihranjivanje riba bjelančevinama životinjskog porijekla). Rezultate ilustriraju tablice 3, 4 i 5. Gubici šarana bili su slični u svim varijantama pokusnih ribnjaka, ipak nešto veći u kontrolnoj, nepovoljnoj varijanti. Prosječna individualna masa šarana bila je uz gnojidbu veća 30%, a uz prihranjivanje bjelančevinastim briketima (20% bjelančevina) 154%. Hranidbeni je koeficijent u gnojenoj varijanti bio 26% niži, a uz prihranjivanje bjelančevinama 13%. Fultonov i Klarkov koeficijent uhranjenosti bio je sličan u svim ribnjacima, s iznimkom boljih vrijednosti Fultonova koeficijenta u varijanti koja je prihranjivana bjelančevinama i koje su bile statistički opravdane (p<0001). U toj je varijanti utvrđena i najveća dužina i težina šarana (p<OOOl). Dodatni prirast riba na račun biljojeda iznosio je 92 kg ha-1 (var I), 404 kg ha-1 (var II) i 650 kg ha-1 (var III), bez nepovoljna djelovanja na prirast šarana.This research was carried out on 8 experimental fish-pounds with individual sizes of 0,1 ha-1 on fish farm Draganići during 1990 culturing season. Carp was reared under conditions of polyculture with total stock density 3250 ind × ha-1. (77 % carp, 2500 ind × ha-1 ; 23% -- 250 ind × ha-1 each species of herbivorous fish – silver carp, bighead, grass carp). The influence of fertilization and different feeding of fish was researched through these parameters: yield and increment of fish, individual weight, losses, food conversion, Fultons and Clark’s coefficient of carp. The hydrochemical conditions in individual pounds where researched too (tabl 2). The total increment of fish was 703 ind × ha-1 (I variant, without fertilization, feeding of carp with cereals), 1302 ind × ha-1 (variant II, fertilization, 500 kg × ha-1 NPK 17: 8: 9, feeding with cereals) and 2537 kg × ha-1 (variant III, without fertilization, feeding carp with pellets containing 20% protein of animal origin). The increment of carps was 611.4; 897.8 and 1923.5 kg × ha-1 resp. The results of production are shown on tables 3, 4 and 5. The losses of carp were similar in all variants of fish-pounds (tabl. 4). The average individual weight of carp was 30% bigger in the fish pond with fertilization, and 154% in fish pond with feeding carp with pellets containing 20% protein of animal origin in compare to control variant 1. Food conversion was lower for 26% in the variant which was fertilized, and for 13% in the variant fed with protein pellets, in compare to control variant l. The Fulton\u27s and Clark\u27s condition coefficient of carp was similar in all experimental ponds except in the variant III. In this variant the Fulton\u27s condition coefficient was significantly better (P<O,OOOl) as well as the length and weight of carp (P). The presence of herbivorous fishes in this polyculture enlarged the total increment of fishes for 92 kg\u27ha-1 (variant I), 404 kg\u27ha-1 (variant II) and 650 kg\u27ha-1 (variant II!), without an inhibitory effect on the growth rate of carp