UTJECAJ CIJEPLJENJA NA RAST KALIFORNIJSKE PASTRVE U KOMERCIJALNOJ PROIZVODNJI

The effect of intraperitoneal (ip) vaccination upon the performance of rainbow trout (n = 1611), maintained under commercial production conditions (aerated spring water, 9.8 ºC, 150 L/min), was evaluated over a 7-week period. Vaccine impact was examined with reference to control (n = 1683) and injected control (sterile filtered water; n = 1537) animals. All groups were run in triplicate (i. e., n 500 fish per gorup). Animals were fed to satiation twice daily. Vaccination suppressed (P500 riba/grupi). Riba je hranjena do sitosti dva puta dnevno. U usporedbi s kontrolnim grupama, cijepljenje je utjecalo na smanjeni prirast (P<0.05) u vrijeme istraživanja. Odgovarajući pad dnevnog prirasta težine (P<0.05), kroz prvih 29 dana pokusa, također je zapažen kod cijepljenih riba. Konverzija hrane, kao i količina obroka bili su slično negativni kod cijepljenih životinja 29 dana nakon cijepljenja (P<0.05). Cjepivo je uzrokovala abdominalnu adheziju, no razlike u kemijskom sastavu tijela nisu ustanovljene

DETEKCIJA RENIBACTERIUM SALMONINARUM U TKIVU POTOČNE ZLATOVČICE (SALVELINUS FONTINALIS) METODOM »NESTED« RT–PCR

Pathogenic bacterium Renibacterium salmoninarum causes kidney disease with high mortality rate and considerable economic losses in salmonid farming. Thus, application of fast and sensitive method for R. salmoninarum diagnosis is of great importance. This paper describes detection of R. salmoninarum in brook trout tissue with gross clinical signs of disease by nested RT–PCR. Determination of partial sequence of bacterial msa gene was done prior to comparison with similar sequences from different R. salmoninarum isolates. Nested RT–PCR proved to be a rapid and valuable diagnostic tool for R. salmoninarum detection, and sequence analysis confirmed previously reported genetic uniformity of this bacteria.Bakterija Renibacterium salmoninarum uzrokuje bakterijsku bolest bubrega karakteriziranu visokom stopom smrtnosti i značajnim ekonomskim gubitcima u uzgoju salmonidnih riba. Zato je primjena brze i osjetljive metode za detekciju R. salmoninarum veoma važna. U radu je opisan nalaz R. salmoninarum u tkivu potočne zlatovčice s karakterističnim kliničkim znakovima bolesti metodom »nested« RT–PCR. Određen je nukleotidni slijed dijela bakterijskog gena msa, koji je zatim uspoređen sa sličnim sljedovima iz različitih izolata R. salmoninarum. »Nested« RT–PCR pokazao se brzom I korisnom dijagnostičkom metodom u detekciji R. salmoninarum, a analiza nukleotidnoga slijeda msa potvrdila je prije uočenu genetičku jednolikost ovih bakterija

GENOTIPIZACIJA VIRUSA IZOLIRANIH IZ KALIFORNIJSKIH PASTRVA (Oncorhynchus mykiss) U HRVATSKOJ

Infectious hematopoietic necrosis virus (IHNV) and infectious pancreatic necrosis virus (IPNV) are important pathogens in rainbow trout aquaculture. Detection of these viruses in Croatia initiated investigation of their genetic relatedness to the worldwide IHNV and IPNV isolates. For this purpose, determination of nucleotide sequences of G and NV genes for IHNV and VP2/NS region for IPNV was performed. Phylogenetic analyses revealed that Croatian IHNV isolate was clustering within European clade most closely related to the North American M genogroup. Croatian IPNV isolate appeared in the cluster of genogroup III, together with French, English, Danish and Norwegian isolates. These results are important for further epidemiological studies of IHNV and IPNV outbreaks in Croatia.Virusi zarazne hematopoezne nekroze (ZHN) i zarazne nekroze gušterače (ZNG) važni su patogeni u uzgoju kalifornijskih pastrva. Nalaz tih virusa u Hrvatskoj potaknuo nas je na istraživanje suodnosa hrvatskih izolata virusa ZHN i ZNG sa svjetskim izolatima. U tu svrhu odre|eni su nukleotidni sljedovi gena G i NV virusa ZHN, te vezne regije VP2/NS virusa ZNG. Filogenetske su analize pokazale da se hrvatski ZHN izolat grupirao u europsku skupinu ZHN izolata, srodnih sjevernoameričkoj genogrupi M. Hrvatski ZNG izolat pripadao je genogrupi III, zajedno s francuskim, engleskim, danskim i norveškim izolatima akvabirnavirusa. Rezultati su značajni za daljnja epidemiološka istraživanja virusa ZHN i ZNG u Hrvatskoj

PHYTOPLANKTON OF VRANSKO LAKE ON THE ISLAND CRES

Kao osobiti prirodni fenomen Vransko jezero s površinom od 5,7 km2 i zapremninom od oko 220 milijuna m3 slatke vode izuzetne kakvoće slabo je istraženo s biološkoga gledišta. Ihtiološka, fizikalnokemijska i bakteriološka istraživanja provedena su u tijeku god. 1989. (lipanj, rujan i prosinac) i 1990. (travanj). Posebna je pozornost posvećena istraživanju strukture fitoplanktona kao pokazatelja kakvoće vode. Uz sakupljanje uzoraka fitoplanktona, mjerene su temperatura i prozirnost vode na pet mjesta (sl. 1). Uzorci fitoplanktona uzimani su na dubinama od 0,5 m, 10 m, 20 m i 40 m. Rezultati srednjih vrijednosti izmjerenih temperatura vode i prozirnosti jezera prikazani su na sl. 2. Temperatura vode uglavnom je bila pod utjecajem okolne temperature zraka. Zapažena je termička stratifikacija u ljetnim mjesecima i pojava izotermije u hladnijem dijelu godine. U kvalitativnom sastavu fitoplanktona utvrđeno je 60 planktonskih alga koje su pripadale sistemnim skupinama: Cyanophyceae, Euglenophyceae, Dinophyceae, Chrysophyceae, Bacillariophyceae i Chlorophyceae (tabl. 1). Iako su brojčano prevladavali predstavnici skupine Bacillariophyceae, u svim uzorcima fitoplanktona Vranskog jezera prevladavala je vrsta Ceratium hirundinella, pripadnik skupine Dinophyceae, indikator oligosaprobnoga stupnja. Osim ove, važnu ulogu u strukturi fitoplanktona imale su vrste Cyclotella comta, indikator oligosaprobnoga stupnja, i Dinobryon diuergens, indikator betamezosaprobnoga stupnja. Na osnovi kvalitativnih analiza fitoplanktona u Vranskom jezeru prevladavali su predstavnici oligosaprobnoga stupnja, što upućuje na dobru kakvoću vode, a kvantitativne analize upozoravaju na oligotrofni karakter jezera. Prema zastupljenosti pojedinih fitoplanktonskih vrsta u vrijeme istraživanja dominantna fitoplanktonska zajednica u jezeru pripadala je tipu Cyclotella--Dinobryon Ceratium.As a special nature phenomenon, Vransko Lake with its ackreage of 5.7 km2 and cubic capacity of 220 million m3 fresh-water of extraordinary quality has been unsufficiently biologically examined. Ichthyological, physical, chemical and bacteriological examination were conducted in 1989 (June, September and December) and 1990 (April), Special attention was given to the examination of phytoplankton structure as an indicator of water quality. In addition to collecting phytoplankton specimen, the temperature and transparency of water were measured at 5 different places (Picture 1). The phytoplankton specimen Were taken at the depths of 0.5 m, 10 m, 20 m and 40 m. The results of medium values of measured water temperature and lake transparency are showed on the Picture 2. The water temperature s was mostly under the influence of surrounding air temperature. The thermic stratification in summer and the manifestation of isotherm in the colder period of year were observed. In the qualitative composition of phytoplankton there were stated sixty plankton algae which belonged to the following system groups: Cyanophyceae, Euglenophyceae, Dinophyceae, Chryslophyceae and Chlorophyceae (Table 1). While representatives of Bacillariophyceae outnumbered other groups, the species Cera- tium hirundinella which belongs to the Dinophyceae group and the indicator of olighosaprobnog degree dominated in all phytoplankton specimen of Vransko Lake. Besides that group, the significant role in the phytoplankton structure had the species Cyclotella comta, the indicator of olighosaprobnog degree and Dinobryon divergens, the indicator of bethamesosaprobnog degree. On the basis of qualitative analysis of phytoplankton, the representatives of olighosaprobnog degree dominated in Vransko Lake what implies good water quality and the quantitative analysis show the olighothrophic lake character. According to representation of particular phytoplankton species at the time of examination, the dominant phytoplankton group in the lake belonged to the type Cyclotella-Dinobryon-Ceratium

ATTACHMENT OF LARVA, SURVIVAL AND GROWTH OF JUVENILE VARIANT SCALLOPS (Chlamys varia Linnaeus, 1758) IN CONTROLLED BREEDING IN ŠARINA DRAGA BAY — MOUTH OF THE KRKA RIVER

Kontrolirani uzgoj male kapice (Chlamys varia Linnaeus, 1758) u Hrvatskoj ne postoji, a iz prirodnih se populacija izlovljava sezonski, sporadično i neorganizirano. Istraživanja indeksa kondicije adultnih malih kapica, prihvata ličinki, stupnja preživljenja i rasta juvenilnih školjkaša provedena su radi utvrđivanja mogućnosti njezina kontrolirana uzgoja. Rezultatima istraživanja utvrđeno je da mala kapica ima dualni tip mriješćenja, s primarnim maksimumom u proljeće (ožujak/svibanj) i sekundarnim u jesen (listopad). Najpovoljnije razdoblje za kolektiranje mlađi jest srpanj/rujan, a najpovoljnija dubina 2–10 m iznad morskoga dna. Najniži salinitet na kojem su utvrđeni prihvat i preživljenje ličinki jest oko 20 x 10–3, a uspješno kolektiranje moguće je uglavnom pri salinitetima višima od 30 x 10–3. U pokusnom su uzgoju male kapice, srednje veličine od 16,4±2,1 do 17,6±2,2 mm i srednje mase 0,95 do 1,35 g, nakon godinu dana postigle srednju veličinu od 42,7±3,2 do 47,5±3,0 mm i srednju masu od 12,1 do 17,5 g. Ukupna smrtnost za vrijeme istraživanja iznosila je od 25 do 57%.In Croatia, the capture of scallop (Chlamys varia Linnaeus, 17583) from natural populations are sporadic and unorganized, while there is no controlled cultivation of this species. To determine the possibility of the establishment of their commercial cultivation, the research comprehended the condition index of adults, larval attachment, juvenile survival and growth in Šarina draga Bay, in a locality with dense scallop populations. The changes of condition index shoved on main spawning season in spring (March–May) and second one, but less intensive, in autumn (October). According to results, the best season for juvenile collection is recommended the period from July to September at depths between 2 to 10 m, and salinities above 30 x 10–3. Low larval settlement at 2.5 m depth is surely result of salinity decrease by Krka river intensive fresh water inflow. Shellfish mean size from 16.4±2.1 to 17.6±2.2 mm and with a mean mass from 0.95 to 1.35 g reached mean size from 42.7±3.2 to 47.5±3.0 mm and mean mass from 12.1 to 17.5 g in one year. Total mortality during this study was ranged from 25 to 57%

First Record of Infectious Haematopoietic Necrosis Virus in Rainbow Trout Fry in Croatia

The paper describes the first diagnosis of infectious haematopoietic necrosis virus (IHNV) in Croatia. The viral causative agent was detected in pooled organ samples from the imported rainbow trout fry on the fish farm. Reverse transcriptase - semi-nested polymerase chain reaction (RT- snPCR) was applied directly on the infected tissue for rapid virus detection. After isolation on cell cultures, IHNV isolate was characterised on the basis of the 303 nt region of the glycoprotein gene (Mid-G) sequence. Phylogenetic comparison to North American and European IHNV isolates revealed that this Croatian isolate belongs to the M genogroup, confirming the prediction of the M genogroup origin of European IHNV isolates. The introduction of the virus presents a threat of further spreading of the disease in Croatia, as the infected farm is in a direct contact with the open waters

POSSIBILITIES OF EXTRACTION AND CULTURE OF RED CORAL (Corallium rubrum, Linnaeus, 1758) IN CROATIA

U radu je prikazano povijesno i religijsko značenje crvenog koralja. Dani su podaci o načinu i količinama vađenja. Detaljno su opisane biologija i fiziologija te životinje. Prikazana je mogućnost kontroliranog uzgoja, te potrebe za daljnjim razvojem. Dane su osnovne smjernice potrebnih znanstvenih istraživanja kako bi se dobili odgovori na niz nepoznanica u biologiji i fiziologiji, pa i patologiji ovoga zanimljivog organizma. Izneseni podaci upozoravaju na nužnost pažljivog pristupa u iskorištavanju toga prirodnog bogatstva.The historical and religious significances of the red corals are presented in the paper. Its biology and physiology are described in details. The possibility of the controlled culture is shown as well as the needs of further development. To get some answers on many unknowns of biology, physiology and pathology of this very interesting organism, the basic trends of the scientific investigations are presented. Obtained data point at the careful exploitation of this natural resources

AEROMONAS SPP BACTEREMIA OF RAINBOW TROUT FRY (ONCORHYNCHUS MYKISS): BIOCHEMICAL CHARACTERIZATION OF THE CAUSATIVE ORGANISM AND ANTIMICROBIAL SUSCEPTIBILITY

Aeromonas hydrophila i druge bakterije roda Aeromonas ubikvitarne su u vodenom okolišu i dio su normalne bakteriološke flore mlađi kalifornijske pastrve. Infekcije uzrokovane tim bakterijama registrirane su u mnogim zemljama svijeta. U ovom su radu prikazana naša iskustva i spoznaje s aeromonasnom bakterijemijom, kao uzrokom uginuća mlađi kalifornijske pastrve. U studenome 2003. pastrvska mlađ u dobi od 7 mjeseci počela je iznenada ugibati. U Laboratorij za istraživanje i razvoj akvakulture dostavljeno je 17 uzoraka riba, uginulih i moribundnih pastrvica, koje su odmah i pregledane. Primjenom Api 20 NE testova identificiran je Aeromonas hydrophila / caviae tip I s 99,9 % točnosti (1 test protiv), odnosno Aeromonas hydrophila / caviae tip II s 99,5 % točnosti (1 test protiv) iz uzoraka uzetih iz jetre, slezene, bubrega, crijeva i očnih lezija. Svi izolirani i identificirani sojevi testirani su na osjetljivost prema antibioticima disk difuzijskom metodom. Utvrđena je najveća osjetljivost na flumekvin, a relativno slabija prema kloramfenikolu i enrofloksacinu. Liječenje je uspješno provedeno Flubactinom®.Aeromonas hydrophila and other members of Aeromonas genus are ubiquitus in aquatic environment and make part of normal bacterial flora of rainbow trout. Aeromonas spp. infections are worldwide registered. Here we present our experience and knowledge on Aeromonas bacteremia, which causes mortality of rainbow trout fry. Rainbow trout fry, 7 month old, started to die in November 2003. Fish samples (17 samples) of dead and moribund fish were delivered to the Laboratory for aquaculture. With Api 20 NE tests Aeromonas hydrophila / caviae type I was identified with an average probability of 99.9 % (one test against), as well as Aeromonas hydrophila / caviae type II with an average probability of 99.5 % (one test against) from liver, spleen, kidney, intestines and damaged eye. All of isolated and identified samples were tested for antibiotic susceptibility by disc diffusion method. The test showed that specimens were most sensitive on flumequin, and relatively less sensitive on chloramphenicol and enrofloxacin. Therapy was successfully applied with Flubactin®

BACTERIAL FLORA OF RAINBOW TROUT LARVAE AND FRY (ONCORHYNCHUS MYKISS)

U dostupnoj literaturi nema podataka o strukturi bakterijske flore kod ličinki i mlađa kalifornijske pastrve u prvim danima života. Zadatak je našeg rada bio pratiti bakterijsku floru od 3. do 8. tjedna života. Tijekom 35 dana pokusa utvrđivana je bakterijska flora kalifornijske pastrve uz praćenje fizikalno–kemijskih parametara kvalitete vode i njezina utjecaja na zdravlje. Uzorci za bakteriološku pretragu uzimani su sa škrga, srca i područja bubrega i inokulirani na podloge. Bakterijske su kolonije pregledane makroskopski, razmazi su obojeni po Gramu, a zatim su načinjeni biokemijski testovi. Pri identifikaciji primjenjivan je APILAB Plus program (bio Mérieux, France). Bakterijska flora ličinki i mlađa kalifornijske pastrve mijenjala se je sa starošću. Fizikalno–kemijske karakteristike vode kretale su se unutar optimalnih vrijednosti. Od inokuliranog materijala najviše je izraslo bakterijskih kolonija s izolata škrga (64,4 %), zatim iz srca (21,8 %) i iz područja bubrega (13,8 %). Bakterijsku floru ličinki u inkubatoru većim su dijelom tvorile gram–pozitivne bakterije (64,7 %), i to vrste: Renibacterium salmoninarum (23,5 %), Lactobacillus spp. (11,8 %), Staphilococcus spp. (17,6 %) i Corynebacterium aquatile (11,8 %). Premještanje ličinki iz inkubatora u bazene reduciralo je bakterijsku floru (–66,7 %) nakon 45 minuta boravka u bazenu. Gram–negativne bakterijske vrste koje su u ličinki u inkubatoru bile zastupljene u niskom postotku (35,3 %), premještanjem ličinki u bazene postale su dominantne i činile su više od 95 % bakterijske flore ličinki, odnosno mlađa kalifornijske pastrve. Flavobacterium, Acinetobacter i Yersinia bili su pretežiti gram–negativni rodovi u ličinki u inkubatoru, dok su Aeromonas, Pseudomonas, Flavobacterium i Pasteurella glavni izolati iz ličinki, odnosno mlađa u bazenima do kraja pokusa. Bakterijska flora ličinki u inkubatoru većinom se sastoji od gram–pozitivne flore, a u ličinaka i mlađa kalifornijske pastrve u bazenima od gram–negativne bakterijske flore.There are no information in available literature about the structure of bacterial flora in rainbow trout larvae and fry in the first days of their lives. The objective of our work has been to follow bacteroflora between the third and the eighth week of their lives. During 35 days of experiment bacteroflora of rainbow trout has been examined, along with following physico–chemical characteristics of water quality as well as it’s influence on health. Samples for bacteriological examination were taken from gill, heart and kidney areas and innoculated on the plates. Bacterial colonies were examined macroscopically, slides with Gram staining, and afterwords biochemical tests were performed. For identification, APILAB Plus programme (bio Mérieux, France) was used. Bacterial population of rainbow trout larvae and fry changed in dependence with their age. Physico–chemical characteristics of water ranged within optimal values. Most of bacterial colonies originated from gill isolates (64,4 %), than from heart (21,8 %) and kidney areas (13,8 %). The bacterial flora of larvae in incubator was composed mostly of Gram–positive bacteria (75,1 %), genera: Renibacterium (25 %), Lactobacillus (16,7 %), Staphilococcus (16,7 %) and Corynebacterium (16,7 %). The transfer of larvae from incubator into the pools resulted in reducing bacterial flora (–66,7 %) after 45 minute stay in the pool. Gram–negative bacteria, which have been represented in larvae in incubator with low percent (24, 9 %), after the transfer of larvae to the pools became dominant and represented more than 95 % of rainbow trout larvae and fry bacterial flora. Flavobacterium, Acinetobacter and Yersinia were the predominant Gram–negative genera in larvae in incubator, whereas Aeromonas, Pseudomonas, Flavobacterium and Pasteurella were the main isolates from rainbow trout larvae and fry until the end of experiment. Bacterial flora of larvae in incubator mostly consists of Gram–positive bacteria, whereas in rainbow trout larvae and fry in pools Gram–negative bacterial flora prevail

PATHOGENIC MICROORGANISMS AND TOXINS THAT SHELLFISH CAN TRANSFER FROM POLLUTED AREAS — ZOONOSES

Školjkaši su često krivci za otrovanje ljudi hranom. U sat vremena jedan školjkaš može profiltrirati osam litara vode. U njoj se tijekom filtriranja vode zadržavaju hrana, akumuliraju se čestice fitoplanktona i razni mikroorganizmi. Neki od mikroorganizama mogu preživjeti u dagnji tako što prijeđu u vegetativni stadij. Ako takvog školjkaša pojede čovjek, u njegovu organizmu mikroorganizam prelazi iz vegetativnog u aktivni stadij i počinje se umnožavati. To u ljudi često rezultira bolestima kao što su trbušni tifus, hepatitis A, salmoneloze, šigeloze, gastroenteritisi i sl. Nadalje, konzumiranje školjkaša kontaminiranih toksičnim algama (dijatomejama, dinoflagelatima) uzrokuje različita otrovanja, a konzumiranje školjkaša iz područja onečišćenih produktima antropogenoga djelovanja može uzrokovati otrovanje teškim metalima.Shellfishes are often responsible for food poisoning. In one hour, one mussel may filtered eight liters of water. During the filtering, in that shellfish are accumulated all sorts of microorganisms and particles. Some of these microorganisms can survive in mussel by converting to vegetative stage. If such shellfish is eaten by human, in his body the microorganism pass from vegetative to active stage and starts to multiply. That in peoples often results in diseases like typhus abdominalis, hepatitis A, salmonella, shigella, gastroenteritis etc. Furthermore, by consuming shellfish that are polluted by the products of anthropogenic action may cause intoxication with hard metals