Repository of the Department of Marine Studies at the University of Split
Not a member yet
318 research outputs found
Sort by
Fish diseases caused by viruses
No full textU ovom radu opisani su virusi i bolesti koje uzrokuju kod riba. Virusi su infektivni entiteti na granici živog svijeta. U jednoj litri morske površinske vode se nalazi 10 milijardi mikroorganizama i 100 milijardi virusa. Virusnoj infekciji podložne su sve skupine živih organizama, od jednostaničnih do višestaničnih. Većinom su virusi korisni u ekosustavu, no određene vrste su patogene što se može negativno odraziti na uzgoj važnih morskih organizama. Ribe su izložene stresu kako u prirodnom okruženju tako i u umjetnom uzgoju. U kontroliranom uzgoju ribe su podložnije infekcijama virusa, za razliku od jedinki koje se nalaze u divljini. Kada dođe do pojave bolesti u populaciji, ne obolijevaju i ugibaju odmah sve ribe. Mnogo je čimbenika koji utječu na reakciju potencijalnih patogenih virusa. Patogen mora uzrokovati bolest, a riba mora biti u osjetljivom stanju da se pojavi bolest. Simptomi virusnih bolesti riba u kontroliranom uzgoju se lakše mogu pratiti nego kod riba na slobodi. Virusne bolesti su dugotrajne i zahtijevaju praćenje, istraživanje i kontroliranje zaraženih jedinki riba.In this thesis are described the viruses and diseases they cause in fish. Viruses are infectious entities at the edge of the life. In one liter of sea surface water there are 10 billion microorganisms and 100 billion viruses. All groups of living organisms, from unicellular to multicellular are susceptible to viral infections. Most viruses are useful in ecosystem, but certain species are pathogenic, which can have a negative impact on the breeding of important marine organisms. Fish are exposed to stress in the natural environment and in fish farming. When the disease is present in one of the fish population, all fish are not affected immediately. There are many factors that affect the response of potential pathogenic viruses. The pathogen must cause the disease and the fish must be in a sensitive condition for disease. Fish that are controlled in cultivation are more susceptible to virus infections than others in the wild nature. Symptoms of viral fish diseases in controlled breeding can be more easily monitored than in the wild fish. Viral diseases are long-lasting and require monitoring, researching and controlling of infected fish species
The effect of fishing gear and postmortem handling on quality changes in fish
No full textU ovom radu dan je pregled novije literature o utjecaju različitih alata i tehnika ribolova na kvalitetu ulova s posebnim osvrtom na utjecaj udičarskih i povlačnih alata kao i postulovnih manipulacija koje mogu pridonjeti kvaliteti ribe u daljnjem rukovanju. Dodatno, opisan je i indeks oštećenja tijekom ulova (engl. catch damage indeks) kao primjer novije metode za procjenu oštećenja komercijalnih vrsta u ulovu. Promjene koje se javljaju tijekom lova i u postulovnoj manipulaciji imaju značajan utjecaj na smanjenje kvalitete ribljeg mesa na način da ubrzavaju posmrtne promjene te dovode do denaturacije dijela bjelančevina, smanjuju kapacitet zadržavanja vode i utječu na okus i boju te prezentaciju mesa ribe. Literatura opisuje mnoge eksperimentalne ribolovne tehnike i poboljšanja alata kojima je za cilj umanjiti djelovanje alata kako bi na tržište došao što bolji i kvalitetniji proizvod. Primjena postulovnih metoda za smanjenje stresa i odgodu posmrtnih reakcija (odmaranje ribe, ošamućivanje ribe strujom, kvalitetno iskrvarenje odmah po ulovu, te uklanjanje utrobe) iziskuje dodatno vrijeme i ljudstvo ali umanjuje posmrtne promjene na mesu čime je i plasman ribe olakšan.In this thesis a review of the latest literature on the effects of fishing gear and catching methods on quality of catch was given, with a particular dedication on the effect of hooks, lines and trawls on post-mortem quality changes in fish. A recently developed catch damage index method was described as a useful tool for assessment of injuries sustained during fishing activities in commercially important species. Impact of fishing and post-mortem handling on the quality of fish flesh is significant and reflected in acceleration of post-mortem changes, denaturation of proteins, reduction in water holding capacity, flash color and taste as well as overall presentation of the fish. Literature describes many experimental fishing methods and gear improvements aimed at reducing the impact of the fishing gear and there for improve the product’s quality on the market. Application of the post-catch methods for reduction of stress and delay of post-mortem reactions (recovery from exhaustive swimming, stunning the fish with electricity, proper exsanguination immediately after catch and evisceration) reduce the post-mortem changes in fish resulting in better quality and easier marketing, however, require additional time and personnel
Otolith morphology and morphometry of the juvenile fish species from genus Symphodus from the Adriatic
No full textTijekom ovog istraživanja, u priobalnom dijelu istočnog Jadrana, ulovljeno je ukupno 58 jedinki nedoraslih stadija riba roda Symphodus, i to tri vrste: Symphodus melanocercus, Symphodus ocellatus i Symphodus cinereus. Raspon ukupne dužine tijela jedinki vrste S. melanocercus nalazio se između 6,0 i 9,0 cm, dok je ukupna dužina tijela jedinki vrste S. ocellatus bila u rasponu od 3,6 do 9,8 cm. Dužinsko – maseni odnosi vrsta S. melanocercus (b = 2,996) i S. ocellatus (b = 3,037) su izometrijski. Dvije nedorasle jedinke vrste S. cinereus imaju ukupnu dužinu tijela 6,6 cm i 7,0 cm. Otoliti nedoraslih jedinki vrsta S. melanocercus i S. ocellatus su ovalnog do klinastog oblika dok su otoliti vrste S. cinereus ovalni. Najbolja veza je utvrđena između dužine otolita i ukupne dužine tijela ribe za vrste S. melanocercus i S. ocellatus, a u radu su prikazane i predikcijske jednadžbe. Dvije jedinke vrste S. cinereus su izostavljene iz morfometrijske analize otolita.During this research, in the coastal eastern Adriatic area 58 juveniles from the genus Symphodus were sampled: Symphodus melanocercus, Symphodus ocellatus and Symphodus cinereus. Total body length ranges of S. melanocercus and S. ocellatus were between 6,0 and 9,0 cm and 3,6 and 9,8 cm, respectively. Length-weight relationships of the S. melanocercus (b = 2.996) and S. ocellatus (b = 3.037) were isometric. Total body length of two juveniles S. cinereus were 6,6 cm and 7,0 cm. Otoliths of the juveniles S. melanocercus and S. ocellatus are oval to sphenoid and of the S. cinereus oval. The best correlation was determined between otolith length and fish total body length for species S. melanocercus and S. ocellatus and in this thesis predictive equations were presented. Two juvenile S. cinereus were left out from the morfometric analysis of otoliths
Development of cancer
No full textRak može nastati zbog pojačane proliferacije različitih vrsta stanica koja se ogleda u poremećenoj kontroli staničnog ciklusa i nepostojanju dodirne inhibicije u kontaktu s drugim stanicama. Razlikujemo dobroćudne tumore koji ostaju ograničeni na mjestu na kojem su nastali od zloćudnih koji se mogu proširiti na ostale organe u tijelu. Fizikalni i kemijski karcinogeni mogu oštetiti DNA i uzrokovati mutacije te pridonijeti nastanku raka stimulirajući proliferaciju stanica. Virusi također mogu uzrokovati nastanak raka. Cilj ovog završnog rada je dati općeniti pregled procesa nastanka raka na molekularnoj i staničnoj razini.Cancer may result as a consequence of increased cell proliferation of any type which is manifested in aberrant cell cycle control and absence of contact inhibition upon physical contact with other cells. The tumors can be benign, remaining at the place of origin, and malignant which can spread on other bodily organs. Physical and chemical carcinogens can damage DNA causing mutations and contributing to growth of cancer by stimulating cell proliferation. Viruses can also cause cancer. Purpose of this paper is to give a general overview of cancer growth process on molecular and cellular level
Associations between fishes and bivalves
No full textU ovome radu opisane su zajednice školjkaša i riba. Ribe formiraju tri tipa partnerstva sa školjkašima: školjkaši ribama služe kao inkubator, kao privremeno sklonište ili kao stalno sklonište. Europska gavčica (Rhodeus amarus) je vrsta ribe iz porodice šarana (Cyprinidae) koja tvori obavezne odnose sa slatkovodnim školjkašima. Školjkaši služe kao inkubatori, pružajući jajima i ličinkama kisik i zaštitu, oslobađajući time ribe od bilo kojeg oblika roditeljske skrbi. U središnjoj i zapadnoj Europi gavčice se mrijeste u četiri vrste školjkaša: Unio pictorum, U. tumidus, Anodonta anatina i A. cygnea. Ženke europske gavčice polažu jaja u unutarnje i vanjske parne škrge školjkaša. One su razvile morfološke, fiziološke i psihološke prilagodbe na inkubaciju jaja u školjkašima. Razvojem unutar školjkaša gavčice izbjegavaju suočavanje s predatorima na početku svog životnog ciklusa. Gavčice polažu manji broj jaja u različite jedinke školjkaša i na taj način mnogi potomci ovih riba preživljavaju čak i ako ugine jedan ili više školjkaša u koje su položili svoje spolne produkte.This thesis presents the relationship between mussels and fish. Fishes form three basic types of partnerships with bivalves: the mussel serving as an incubator, as a temporary shelter or as a permanent shelter. European bitterlings (Rhodeus amarus) are small cyprinid fishes that form obligatory associations with freshwater mussels. The mussels serve as incubators, providing the eggs and larvae with oxygen and protection thus releasing the fish from any form of parental care. In central and western Europe bitterlings spawn in four species of freshwater mussels: Unio pictorum, U. tumidus, Anodonta anatina and A. cygnea. Female European bitterlings deposit eggs into both inner and outer paired gills of mussels. They display remarkable morphological, physiological and behavioral adaptations for using mussels as incubators for their eggs. Due to their development inside the mussel the bitterlings were relieved from coping early in their life with predators. Many of the bitterling species, place a few eggs into different mussels, thus many offspring still survive even if one or several mussels, in which they laid their sex products, died
Determining selectivity of picarel in diamond mesh netting using modified fishselect metodology
No full textZa potrebe ovog rada uzorkovane su 82 jedinke gire, Spicara smaris (Linnaeus, 1758) uhvaćene obalnom potegačom migavicom na području Hvara. Dužinski raspon uzorkovanih gira iznosio je od 7,5 cm do 16,4 cm. Testom propadanja svaka gira se pokušala provući kroz niz romboidnih oka točno definirane veličine i kuta između susjednih stranica. Na temelju rezultata provlačenja kreiran je model za predikciju selektivnosti oka upotrebljenih u testu propadanja. Prediktivni model je zatim iskorišten za utvrđivanje distribucije mrežnih oka u vreći pridnene povlačne mreže koće izrađene od romboidnog oka veličine 42,4 mm za koju nam je poznata selektivnost. Za navedenu vreću ustanovljeno je da kutovi od 25° do 45° najviše doprinose objašnjavanju eksperimentalne krivulje.For this study, a total of 82 specimens of picarel Spicara smaris (Linnaeus, 1758), were collected in the Adriatic Sea, using the small coastal boat seine “migavica”. The specimens were ranging from 7,5 to 16,4 cm in total length. Fall-through experiments were carried out to decide if each fish can physically pass through series of diamond meshes with defined sizes and opening angles. The results of the fall-through experiment were used to create a predictive size selection model for the meshes used in the fall-through experiment. The predictive model was used to determine the distribution of the mesh opening angles in 42,4 mm diamond bottom trawl codend for which size selection is known. The angles mostly varied from 25 to 45 degrees
The influence of hook type on catch efficiency of hook-based fishing gears
No full textUdica je osnovni element udičarskih alata. Odabir adekvatne udice prvenstveno ovisi o vrsti i veličini ciljane lovine, a ribolovcima je trenutno na tržištu dostupan jako velik broj udica različitih veličina i oblika. U ovom radu pozabavit ćemo se usporedbom dva karakteristična oblika udica, tradicionalnim „J“ i okruglim „O“ oblikom udice. Jedna od osnovnih prednosti okrugle udice u odnosu na tradicionalni „J“ oblik je što okrugla udica ima manju vjerojatnost dubinskog kačenja lovine, što je posebno važno kod „ulovi i pusti“ ribolova. Generalno gledajući, okrugla udica nije toliko efikasna u ulovu u odnosu na tradicionalni oblik udice, ali to prvenstveno ovisi o vrsti koja se izlovljava. U gospodarskom ribolovu pelagičnim parangalima upotreba okruglih udica pokazala se značajnim faktorom, koji doprinosi smanjenju ulova neciljanih vrsta poput morskih kornjača, zbog čega je u nekim ribarstvima upotreba okruglih udica postala zakonska obaveza.Fish hook represents one of the most important tools in human history. Today, fishermen have huge number of fish hooks available to them when preparing for fishing. The size and shape of hooks mostly depend on the size and species of targeted fish. In this paper, we are concentrating on the comparison of traditional „J“ and circle „O“ shape hooks. The use of circle hooks often results in shallow hooking compared to traditional “J” type hooks, what has been recognized as a major advantage in “catch and release” fisheries. In general, results showed that circle hooks have significantly lower catch efficiency compared to “J” type hooks. In pelagic trawl fishery, the use of circle hooks proved to be a significant factor affecting mortality of bycatch species such as sea turtles, which is the reason why in some countries circle hooks are mandatory
LC-MS / MS DETERMINATION OF GYMNODIMINE IN MUSSELS, Mytilus galloprovincialis (Lamarck, 1819) FROM AQUACULTURE and WILD WARTY VENUS, Venus verrucosa (Linnaeus, 1758)
No full textGimnodimin (GYM) je neurotoksin iz grupe cikličkih imina koji primjenom biološkog testa na miševima (MBA) rezultira neurološkim simptomima. Istraživanjem kontaminiranih školjkaša na Novom Zelandu ustanovljeno je da ne predstavlja opasnost za ljudsko zdravlje. Do danas nisu određeni dozvoljeni maksimalni maseni udjeli GYM-a. S obzirom da nema dovoljno istraživanja i prikupljenih informacija o ovom toksinu, potrebna su temeljita i konstantna praćenja. U ovom radu ispitali smo vremensku i prostornu raspodjelu GYM-a u Jadranskom moru na 8 kontolnih točaka važnih za gospodarstvo školjkaša kroz 4 termina. U svim područjima uzorkovane su dagnje (Mytilus galloprovincialis) osim u Mlinicama gdje su uzorkovane brbavice (Venus verrucosa). Identifikacija i kvantifikacija GYM-a ustanovljene su metodom tekućinske kromatografije i masene spektrometrije (LC-MS/MS). Mjerenja su obavljena u metanolskom ekstraktu ukupnog jestivog mekog tkiva školjkaša. Rezultati su pokazali da brbavice Kaštelanskog zaljeva (Mlinice) sadrže veće masene udjele, dok dagnje iz Malostonskog zaljeva sadrže manje prosječne masene udjele GYM-a. Mjerenja su također pokazala različite nepredvidive oscilacije zbog kojih se nije mogla definirat ovisnost o prostorno-vremenskim karakteristikama.Gymnodimine (GYM) is a emerging toxin from the cyclic imine group that in mouse bioassay experiments (MBA) results in neuorological symptoms. Accidental human consumption of contaminated shellfish in New Zealand concluded that GYM does not pose a risk for human health. Maximum permitted level of GYM are not established. Since there is not enough research and information collected about this toxin, thorough and constant monitoring is required. In this paper, we investigated the temporal and spatial GYM distribution in the Adriatic Sea at eight control points which are shellfish breeding areas. During four samplings mussels (Mytilus galloprovincialis) were collected from all investigated control points except for one (Mlinice) where clams (Venus verrucosa) were collected. Identification and quantification of GYM were confirmed by the liquid chromatography and mass spectrometry (LC-MS/MS) in methanol extract of whole edible soft tissue of the shellfish. The results showed that clams from Kaštela bay (Mlinice) have higher concentrations than the mussels from Malostonski Bay (presented lower average concentrations of GYM). The measurements also showed different unexpected temporal oscillations, therefore, spatial-temporal GYM dependence could not be define
Meiofauna and climate change
No full textKako bi se što bolje prikazali utjecaji globalnih promjena na morske ekosustave, od obalnih do dubokomorskih staništa, koriste se organizmi-modeli koji prikazuju posljedice tih promjena. U ovom radu su navedeni primjeri istraživanja u kojima se koriste organizmi meiofaune kako bi se prikazale posljedice klimatskih promjena i antropogenih utjecaja.In order to describe better the impacts of global change on marine ecosystems, from coastal to deep-sea habitats, model organisms are used as thay show the consequences of these changes. This paper provides examples of researches using meiofauna organisms in order to show the effects of climate change and anthropogenic impacts
Microbiological degradation of oil in the marine environment
No full textNafta se koristi kao izvora za dobivanje goriva već od 1860. godine, te se njezina eksploatcija povećava sa godinama. Razlog tomu je što, se otkrićem njezinih derivata i njihovom preradom, dolazi do njihovog korištenja u proizvodima za svakodnevni život poput plastike, odjeće, namještaja, izolacija, kuhinjskih potrepština, automobila, pa čak i u hrani. S povećanjem potražnje nafte u industriji dolazi do izrazitog povećanja njene eksploatacije iz tla koja se kasnije proširuje i u morski okoliš. Nažalost s povećanjem eksploatacije dolazi do povećanog rizika zagađenja i havarija koje mogu imati katastrofalne posljedice u okolišu u kojem se dogode. Zato prijašnje (fizičke i kemijske) metode postaju sve neprihvatljivije u ekološkim krugovima, te dolazi istraživanja i razvitka bioloških metoda. One koriste mikroorganizme i biljke koje imaju sposobnost razgradnje nafte i njenih derivata, te mogućnost obogaćivanja i obnove zagađene okoline.Oil has been used as a fuel source since 1860, and its exploitation has increased with age. The reason is that, with the discovery of its derivatives and their processing, they are used in everyday life products such as plastics, clothing, furniture, insulation, kitchen supplies, cars and even food. With the increase in oil demand in industry, there is a marked increase in its exploitation from the soil, which later expands into the marine environment. Unfortunately, with increased exploitation, there is an increased risk of pollution and damage, which can have catastrophic consequences in the environment in which they occur. That is why the previous (physical and chemical) methods are becoming more and more unacceptable in ecological circles, and the research and development of biological methods is more favoured. They use microorganisms and plants that have the ability to break down oil and its derivatives, and the ability to enrich and restore polluted environments