Repository of the Department of Marine Studies at the University of Split
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Taxonomic identification and determining abundance of dinoflagellate cysts Lingulodinium polyedra (F. Stein) J. D. Dodge, 1989 in sediment core from Kastela bay
No full textU ovom diplomskom radu su predstavljeni rezultati istraživanja trajnih cista Lingulodinium machaerophorum dinoflagelata Lingulodinium polyedra. Identificiranje trajnih cista te opažanje i mjerenja morfoloških značajki istih provedeno je na invertnom mikroskopu (LEICA) pri povećanju od 200 puta. Trajne ciste identificirane su po veličini i obliku nastavaka koji su šuplji i zašiljeni na vrhu. Potvrđeno je da salinitet utječe na morfološke promjene kod ciste L. machaerophorum, točnije proporcionalno sa salinitetom povećava se dužina šiljastog nastavka u rasponu od 12 do 25 μm. Priprema uzoraka za mikroskopiranje provedena je po standardnoj palinološkoj metodi. Za praćenje gubitka broja cista prilikom pripreme uzoraka dodana je Lycopodium tableta koja sadrži spore koje se također broje pri mikroskopiranju u cilju procjene gubitka cista u procesu pripreme uzorka. Rezultati su pokazali da je 76 % spora izgubljeno u pripremi uzorka za mikroskopiranje što upućuje na potrebu dorade same metode kako bi se smanjili gubitci.This Master's thesis presents results from investigation of resting cyst Lingulodinium machaerophorum of dinoflagellate Lingulodinium polyedra. The identification of resting cysts, observations and measurements of their morphological features were conducted on an inverted microscope (LEICA), using 200x magnification. Resting cysts were identified by the size and shape of the processes that are hollow and pointed at the apex. The salinity was found to have the greatest influence on changes of morphological features, more precisely, in proportion to the salinity the length of processes increased in range from 12 to 25 μm. Sample preparation for microscopy was performed according to the standard palynological preparation method. To monitor the loss of cysts during preparation, a Lycopodium capsule with known amount of spores was added and the spores counted. We found that 76 % of the spores were lost during the sample preparation, therefore it is necessary to improve the method in order to reduce losses
Adaptation of marine organisms to environment and environmental changes
No full textU ovom radu su prikazane promjene koje se događaju u morskom okolišu te adaptacije organizama na te promjene. Globalno zatopljenje i prekomjerni ribolov samo su neki od uzročnika promjena u morskom okolišu koje prisiljavaju neke od vrsta na adaptacije. Odgovori organizama variraju od vrste do vrste. Kod nekih vrsta se ukazuje znatna mogućnost prilagodbi na nagle promjene bilo to zbog velike genetske raznolikosti ili drugih mehanizama, dok kod nekih vrsta to nije slučaj. Sposobnost adaptacije uvelike ukazuje na to koji bi organizmi mogli preživjeti a koji ne, nastavi li se trend naglih promjena u morskom okolišu.This thesis presents the changes that occur in the marine environment and the adaptation of organisms to these changes. Global warming and overfishing are just some of the causes of changes in the marine environment that force species to adapt. The way of adaption varies from species to species. Some species show a noticeable ability to adapt to rapidly changing environments, either because of high genetic variability or some other mechanisms, while other species dont show that ability. The ability to adapt gives the insight on what type of organisms could survive or not, in case the trend of a rapid changing sea environment continues
Technological procedure of Venus verrucosa Linnaeus, 1758
No full textU ovom radu predstavljena je važna, autohtona jadranska vrsta, brbavica Venus verrucosa, Linnaeus, 1758, opće biologijske karakteristike vrste, njen rast, reprodukcija i životni ciklus. Rad također, obrađuje problematiku vezanu za održivo gospodarenje vrstom V. verrucosa kao i na pokušaj integracije iste u proces uzgoja . Do danas, djelomično uspješan uzgoj brbavice ostvaren je samo u Španjolskoj. Dosadašnja istraživanja na uzgoju brbavice su omogućila bolju upućenost o uzgojnom ciklusu vrste, ishrani i reprodukciji. Premda potencijal postoji, u Hrvatskoj uzgoj brbavice nije uspostavljen. Daljnji napredak u istraživanjima na ovoj vrsti i njeno uključenje u akvakulturu, može zadovoljiti tržišne potrebe, a na taj način i smanjiti ribolovni pritisak na populacije u divljini. Međutim, za uspješan uzgoj ove vrste primarno je uspostaviti kontrolirani mrijest u uzgojnim jedinicama.This paper presents an important, autochthonous Adriatic species, warty venus, Venus verrucosa Linnaeus, 1758, the general characteristics off this species, its growth, reproduction and life cycle. In addition, the paper deals with issues related to sustainable management of this species as well as the attempt to engage in aquaculture. which has so far been partially successfully achieved only in Spain. Previous research on the conditioning of warty venus has provided a better understanding of the breeding cycle of the species, nutrition and reproduction. Although there is potential, the cultivation of warty venus has not been established in Croatia. Further progress in research on this species and its inclusion in aquaculture, can meet market needs and reduce fishing pressure on wild populations. However, for successful breeding of this species, spawning control in breeding units is the priority
The impact of different nutrition of seabass juveniles Dicentrarchus Labrax (Linnaeus, 1758) on the growth and quality of the fillet
No full textGlavni izvori hrane za akvakulturu su riblje brašno i ulje što nije dugoročno održivo te se danas intezivno istražuje mogućnost uvođenja alternativnih izvora poput biljaka i kukaca. U ovom istraživanju testirano je pet pokusnih ishrana mlađi lubina Dicentrarchus labrax s različitim udjelom i podrijetlom biljnih/animalnih obroka, uz komercijalnu hranu. Dvije su predstavljale negativnu (CVEG), odnosno pozitivnu kontrolu (CFISH) te su sadržavale visoki udio biljnih, odnosno ribljih proteina i ulja. Ostale hrane su sadržavale glavninu biljnih proteina s dodatkom proteina kukca Hermetia illucens (CVEG+HM), kombinaciju biljnih proteina, nusproizvoda iz industrije peradi i kukca (CVEG+PBM+HM) i visoki udio ribljeg proteina i ulja s dodatkom kukca (CFISH+HM). Na kraju pokusnog razdoblja od 125 dana, skupina hranjena komercijalnom hranom imala je najveći rast u dužinu (49,11%) i u masu (85,95%), dok je najmanje povećanje dužine (42,2%) i mase (80,41%) zabilježeno u skupini CVEG. Skupina CFISH je imala sličan rast kontrolnoj skupini. Najviša vrijednost indeksa kondicije je zabilježena za CFISH+HM (1,28 ± 0,01). Skupina CFISH je imala najbolji indeks konverzije hrane (0,97 ± 0,02), najnižu energetsku vrijednost fecesa (234,54 ± 7,12 kcal), odnosno najveću iskoristivost hrane, te najveći sadržaj ukupnih lipida u filetima. Kod ishrane s većim sadržajem omega-3 i -6 masnih kiselina podrijetlom iz kukca, odnosno ulja repice i lana (CFISH+HM, odnosno CVEG), zabilježen je i veći sadržaj istih u filetima mlađi lubina. Rezultati ukazuju na važnost ribljih obroka u ishrani mlađi lubina i u ovoj fazi razvoja alternativni izvori proteina i ulja se nisu pokazali jednako učinkovitima.Given that the main sources of food for aquaculture are fishmeal and oil, which is not sustainable in the long run, the nutritional potential of alternative sources such as plants and insects is being intensively explored. In this study, five experimental diets of juvenile sea bass Dicentrarchus labrax were tested with different proportions and origins of plant/animal meals, in addition to the commercial diet. Two were negative (CVEG) and positive control (CFISH) and contained a high proportion of vegetable and fish proteins and oils, respectively. Other diets contained the majority of plant proteins with the addition of insect protein from Hermetia illucens (CVEG+HM), a combination of plant proteins, by-products from the poultry industry and insect meal (CVEG+PBM+HM) and a diet with high proportion of fish protein and oil and insect meal (CFISH+HM). After 125 days of the feeding trial, the group fed commercial diet demonstrated largest increase in length (49.11%) and weight (85.95%), while the smallest increase in length (42.2%) and weight (80.41 %) was recorded for the CVEG group. The CFISH group had similar growth to the control group. The highest value of the condition index was recorded for CFISH+HM (1.28 ± 0.01). The CFISH group had the best food conversion index (0.97 ± 0.02), lowest fecal energy value (234.54 ± 7.12 kcal), i.e. the highest food utilization rate, and the highest total lipid content in fillets. Experimental groups fed diets with a higher content of omega-3 and -6 fatty acids originating from insect meal or rapeseed and flaxseed oil respectively (CFISH+HM and CVEG) demonstrated a higher content of these acids in sea bass fillets. The results underline the importance of fish meals in the diet of juvenile sea bass and alternative sources of dietary protein and oil cannot meet the demands of fish at this developmental stage
Research of biological and ecological characteristics of invasive species Magallana gigas in Adriatic sea
No full textPacifička kamenica Magallana gigas (Thunberg, 1793) unesena je 1960-ih godina u Europu za potrebe akvakulture. U Jadranu je prvi put opisana 1970-ih godina u Limskom zaljevu, ali nije nikad uzgajana u Hrvatskoj. Do danas je zabilježeno jako malo dostupnih podataka o ovoj invazivnoj vrsti u Jadranu. Cilj ovog diplomskog rada bio je opisati reproduktivni ciklus te brojnost i strukturu populacije pacifičke kamenice u Limskom zaljevu. Istraživanje je provedeno u periodu od veljače 2017. do listopada 2018. godine tijekom kojeg se pratio reproduktivni ciklus pacifičke kamenice putem histološke analize gonadnog tkiva. Nadalje, na četiri lokacije unutar Limskog zaljeva provela se analiza brojnosti te duţinske strukture ove vrste. Rezultati su pokazali da su uvjeti u Limskom zaljevu pogodni za razmnoţavanje vrste M. gigas te se ona mrijesti uglavnom u ljetnom periodu. Muţjaci i ţenke imali su sinkroni reproduktivni ciklus s malim razlikama u procesu gametogeneze. Brojnost ove vrste u Limskom zaljevu bila je jako visoka te se kretala od 33 do 248 jedinki/m2. Raspon veličina kretao se od 21 do 89 mm. Navedeni podatci predstavljaju prve kvantitativne podatke za ovu vrstu u Jadranu te zajedno s rezultatima reproduktivnog ciklusa potvrĎuju da je pacifička kamenica u Limskom zaljevu uspostavila samoodrţive divlje populacije.Pacific cupped oyster Magallana gigas (Thunberg, 1793) was introduced to Europe in the 1960s for aquaculture purposes. It was first described in the Adriatic Sea in the 1970s, in the Lim Bay, though this species has never been cultivated in Croatia. There are still very limited available information about this invasive species in the Adriatic. The aim of this thesis was to describe the reproductive cycle, size and structure of population of the Pacific cupped oyster in the Lim Bay. The research was carried out in the period from February 2017 to October 2018 during which the reproductive cycle of the Pacific cupped oyster was followed through the histological analysis of the gonadal tissue. Furthermore, on four locations along the Lim Bay analysis of the size of the length structure of this species was conducted. The results showed that the conditions in the Lim Bay are suitable for reproduction of this type of M. gigas and that it spawns mainly in the summer period. Male and female oysters had a synchronous reproductive cycle with minor differences in the process of gametogenesis. Population of this oyster species in the Lim Channel was very high and ranged from 33 to 248 individuals/m2. The range in size varied from 21 to 89 mm. The given data represents the first quantiative figures for this species in the Adriatic Sea and prove, together with the reproductive cycle results, that the Pacific cupped oyster in the Lim Bay has developed self-sustaining wild populations
Viral infections in aquaculture
No full textVirusi zauzimaju posebno mjesto u okolišu jer ih svakodnevno na milijarde unosimo u naš organizam disanjem ili jedenjem. U okolini imaju osobine neživih molekula, dok u inficiranoj stanici domaćina postaju živi preuzimanjem translacijskog mehanizma. Svaki mililitar morske vode sadrži preko milijun virusnih čestica. U morima inficiraju sve organizme, od jednostaničnih bakterija pa do višestaničnih kralježnjaka. Jedan dio virusa u moru su potencijalni patogeni koji mogu inficirati komercijalno važne uzgojne vrste. Povećavanjem broja značajnih komercijalnih morskih vrsta riba u kontroliranom uzgoju sve je veći broj patoloških stanja uzrokovanih virusima. Kako bi spriječili pojavu virusnih infekcija potrebno je proučiti njihove osobine koja će nam koristiti za buduća istraživanja.Viruses hold a special place in the everyday life because a billion of them is brought inside our bodies every day with breathing or eating. In the environment, they have the properties of inorganic molecules, while in an infected host cell, they become alive by taking over the translational machinery. Each millilitre of seawater contains over one million viral particles. In the marine environment, they infect all organisms, from unicellular bacteria to multicellular vertebrates. Part of marine viruses is potential pathogens that can infect commercially important aquaculture species. With the increase of aquacultured marine organisms in a controlled environment, the number of viral pathogens is also increasing, thus causing the illness and eventually a problem in the aquaculture. To prevent the occurrence of viral infections, it is necessary to study viruses, which will useful for future research
Tumor viruses
Get PDFU ovom radu prikazan je pregled značajnijih vrsta tumorskih virusa koji su podijeljeni s obzirom na osnovnu morfologiju, kemijski sastav i način replikacije. Onkogen je stanični ili virusni gen koji može inducirati transformaciju stanica, a onkogeni virusi su oni koji mogu inducirati tvorbu tumora. Članovi šest različitih obitelji virusa sposobni su izravno uzrokovati zloćudni tumor u životinjama ili ljudima. Virusi, koji pripadaju pet od tih obitelji, imaju DNK genom i nazivaju se DNK tumorskim virusima. Članovi šeste obitelji tumorskih virusa, retrovirusi, imaju RNK genom u virusnim česticama. DNK tumorski virusi su Hepatitis B virus, SV40 i poliomavirus, Papilomavirusi, Adenovirusi i Herpesvirusi, a u RNK tumorske viruse ubrajaju se Retrovirusi. Put od virusne infekcije do onkogeneze je spor i samo mali broj zaraženih osoba napreduje do zloćudnih tumora, budući da primarna infekcija virusom općenito nije dovoljna za zloćudni tumor.A review of the types of tumour viruses is presented in this thesis. Viruses are divided based on basic morphology, chemical composition and replication. Oncogene is a cell or viral gene that can induce cell transformation, and oncogenic viruses are viruses that can induce tumour formation. Members of six different family of viruses are capable of directly causing cancer in animals or humans. Viruses that are part of five of these families have DNA genomes and are called DNA tumour viruses. Members of the sixth family of tumour viruses, retroviruses, have RNA genomes in viral particles. DNA tumour viruses are Hepatitis B virus, SV40 and poliomavirus, Papillomaviruses, Adenoviruses and Herpesviruses, and RNA tumour viruses are Retroviruses. The path from viral infection to tumorigenesis is slow and only a small number of people are progressing to cancer, since primary infection with the virus is generally insufficient for cancer
Sediments and sedimentation changes at one station in Kaštela Bay
No full textU ovom su diplomskom radu predstavljeni rezultati tri uzorkovanja (2015., 2017. i 2018. godine) na centralnoj postaji u Kaštelanskom zaljevu. Obradom 69 uzoraka sedimenta ustanovljeno je da na istraživanoj postaji prevladava taloženje čestica veličine gline (54,95± 7,18%) i silta (43,63 ± 7,34%). Prevladavanje loše sortiranog sedimenta ukazuje na različito podrijetlo istaloženih čestica u sedimentu koje su najčešće nekarbonatne (41,08± 6,62% karbonata). Prema Shepardovoj klasifikaciji najzastupljenija je siltozna glina, a prema Folkovoj klasifikaciji najzastupljeniji je neznatno šljunskoviti mulj. Promjene duž jezgara, kao i između njih, upućuju na postojanje tri ekološka uvjeta u sedimentaciji koji nastaju kao posljedica pretaloživanja sedimenta iz plićeg područja u centralni dio Kaštelanskog zaljeva, ali i njegovog odnošenja u izlazni, dublji dio.This thesis presents the results of three samplings (2015, 2017 and 2018) at the Central station in Kaštela Bay. Analysis of 69 sediment samples showed that precipitation of clay particles (54,95 ± 7,18%) and bridge (43,63 ± 7,34%) prevalied in the investigated station. Prevalence of poorly sorted sediments indicates different origins of precipitated particles in the sediments that are most commonly uncarbonated (41,08 ± 6,62%). According to the Shepard classification, silty clay is most common, and according to Folk classification the most common is slightly gravelly mud. The changes along the cores, as well as between them, indicate existence of the three ecological conditions in sedimentation from the shallow part of the central part of the Kaštela Bay, as well as its displacement into the outgoing, deeper part
Analysis of the flood of 29 October 2018
No full textOvaj rad donosi pregled oceanografske situacije od 29. listopada 2018. godine kada je značajni broj mjesta na Jadranskoj obali pogodila poplava. Za promatranje i analizu situacije korišteni su minutni podaci sa mareografskih i meteoroloških postaja. Obradom podataka dobiveni su odgovori na pitanje o meteorološkim i oceanografskim uvjetima koji su vladali taj dan i koji su prouzročili značajno podizanje razine mora. Značajnije podizanje razine mora zabilježeno je na postajama stacioniranim na području sjevernog Jadrana, u usporedbi sa postajama na području južnog Jadrana. Analizom su utvrđeni značajniji utjecaji produbljenja tlaka zraka te pojačanja brzine vjetra na poplavu od 29. listopada 2018. godine.This paper gives an overview of the Adriatic ocean state on October 29, 2018, when a significant number of places on the Adriatic coast were hit by the flood. Minute data from mareographic and meteorological stations were used to analyze the situation. The processing of the data provided answers to a question about the meteorological conditions which prevailed that day and which caused a significant rise in sea level. Significant sea-level rise was observed at stations stationed in the northern Adriatic, while sea-level rise was not significant at stations in the southern Adriatic. The analysis identified significant impacts of deepening air pressure and wind speed increasea on floods of October 29, 2018
The circulation of water massen in the Adriatic sea and an overwiew of the measuring methods
No full textU ovom radu opisana je cirkulacija vodenih masa Jadranskog mora. Uz to prikazani su faktori koji utječu na nastanak morskih struja, njihove različitosti i metode mjerenja kroz povijest. Jadransko more relativno je plitko i poluzatvoreno more koje je duboko usječeno u kopno ukupne površine 138,595 km2. Jadran je izduženi bazen dužine oko 800 i širine od 250 km, položen približno u smjeru jugoistok-sjeverozapad s nerazvedenom zapadnom i vrlo razvedenom istočnom obalom. Zbog njegovog oblika i smještaja sustav površinskih struja u Jadranu posljedica je razdiobe termohalinih svojstava. Uz istočnu obalu Jadrana javlja se ulazna struja koja transportira slanu mediteransku vodu u Jadran, dok se uz zapadnu obalu Jadrana odvija istjecanje manje slane vode iz Jadrana. Gradijenti gustoće osnovni su uzrok generalne ciklonalne cirkulacije, pri čemu je ulazna struja zimi više izražena uz istočnu, a izlazna struja ljeti uz zapadnu obalu Jadrana. Mjerenja vodenih masa u Jadranu obavljaju se korištenjem direktnih i indirektnih metoda. Pod direktnim metodama možemo navesti mjerenja Ekmanovim i autonomnim strujomjerima, a pomoću indirektnih metoda određuju se geostrofičke struje.This paper describes the circulation of the water masses in the Adriatic Sea. In addition, factors affecting the occurrence of sea currents, their differences, and methods of measurement throughout history are presented. The Adriatic Sea is a relatively shallow and semi-enclosed sea that is deeply incised into the continent with a total surface area of 138,595 km2. It is an elongated basin about 800 km long and 250 km wide, lying approximately southeast-northwest with undeveloped west and very indented east coast. Due to its shape and position, the system of surface currents in the Adriatic is a consequence of the distribution of thermohaline properties. Along the east coast of the Adriatic, there is an incoming current that transports saline mediterranean water into the Adriatic, while less salty water flows from the Adriatic along its western coast. Density gradients are the main cause of general cyclonic circulation, with the incoming current being more pronounced in winter along the eastern and the outflowing current in summer along the west coast of the Adriatic. Measurements of water masses in the Adriatic sea are performed using direct and indirect methods. By direct methods, we can indicated measurements by Ekman and autonomous current meters, and by indirect methods, we can state geostrophic currents