Repository of the Department of Marine Studies at the University of Split
Not a member yet
318 research outputs found
Sort by
Endangered species of Adriatic phytobenthos
No full textNapredak civilizacije i ekološka ravnoteža na Zemlji direktno ovise o stanju biološke
raznolikosti. Iako je do sada utvrđeno preko 7000 biljnih i životinjskih vrsta u Jadranskom
moru, važno je istaknuti da je biološka raznolikost i dalje nedovoljno istražena. Posljednjih
desetljeća dolazi do promjene u brojnosti i sastavu bentoske flore Jadranskog mora, a neke od
ugroza predstavljaju ljudska djelatnost, razvoj ježinaca, pojava invazivnih vrsta te klimatske
promjene. U radu je naglašena važnost očuvanja biološke raznolikosti, rizici ugroženosti te
kategorije ugroženosti. Također, pojašnjena je definicija fitobentosa sa pripadajućim
značajkama. Detaljno su opisane odabrane skupine ugroženih alga i morskih cvjetnica te je
istaknuto da do danas nije provedeno detaljno kartiranje morske flore, a svi podaci o
rasprostranjenosti svojti Jadranskog mora, neovisno o razini ugroženosti, su zapravo
nepotpuni.The progress of civilization and the ecological balance on Earth directly depends on the state of
biological diversity. Although over 7,000 plant and animal species have been so far identified
in the Adriatic Sea, it is important to point out that biodiversity remains insufficiently studied.
Recently, there have been changes in the number and composition of the benthic flora of the
Adriatic Sea, due to threats like human activities, sea urchin grazing, the emergence of invasive
species and climate change. This paper emphasizes the importance of biodiversity, the risks,
and categories of endangerment, as well as phytobenthos definition with its features. Selected
groups of endangered algae and sea grasses are elaborated in detail, and it is emphasized that
even today a detailed mapping of marine flora has not been conducted, independently of level
of endangerment, and the data on the species distribution in Adriatic Sea are still incomplete
The role of transposable genetic elements in adaptation
No full textU ovom završnom radu opisana je uloga pokretnih genetičkih elemenata, transpozona (TE), u
evoluciji genoma, stvaranju genetičke raznolikosti, adaptaciji i invazivnosti vrsta.
Transpozoni se dijele na DNA transpozone i retrotranspozone koji se razlikuju prema načinu
premještanja u genomu. DNA transpozoni se uglavnom premještaju tzv. „isijeci i prenesi“
mehanizmom, a retrotranspozoni „kopiraj i prenesi“ mehanizmom i sličniji su virusima.
Transpozoni su snažni insercijski mutageni te mogu imati i pozitivne i negativne utjecaje na
domaćina. Prisutni su u genomima svih organizama, a kod nekih čine većinu sadržaja
genoma. Kralježnjaci su skupina organizama koji su evolucijski jako uspješni i imaju
strukturno i funkcionalno složene genome koji sadrže sve vrste TE elemenata. Smatra se da su
oni imali značajnu ulogu u njihovoj evoluciji. Kontrola transpozicije u genomu se
prvenstveno odvija epigenetski, putem RNA interferencije ili DNA metilacije. Aktivacija TE
elemenata može biti posljedica relaksacije epigenetske kontrole uzrokovane promjenama u
okolišu, posebno u uvjetima stresa. Smatra se i da je prilagodljivost invazivnih vrsta, unatoč
smanjenoj genetičkoj raznolikosti zbog učinka uskog grla, u vezi s aktivnošću transpozona
koji stvaraju nove varijacije i raznolikost. Opisani su primjeri kod različitih vrsta.In this thesis, the role of mobile genetic elements, transposons (TEs), in genome evolution,
genetic diversity creation, adaptation and species invasiveness is described. Transposons are
classified as DNA transposons and retrotransposons, which differ in the way they move in the
genome. DNA transposons move by the so-called. "cut and paste" mechanism and
retrotransposons employ "copy and paste" strategy and are more similar to viruses.
Transposons are potent insertional mutagens and can have both positive and negative effects
on the host. They are present in the genomes of many organisms, and most of the times
constitue a large proportion of the genome. Vertebrates are a group of organisms that are
evolutionarily very successful and have structurally and functionally complex genomes that
contain all types of TE elements. They are thought to have played a significant role in their
evolution. Transposons are controlled at the epigenetic level, via RNA interference or DNA
methylation. Activation of TE elements may be due to relaxation of epigenetic control caused
by changes in the environment, especially under stress conditions. The adaptability of
invasive species, despite their reduced genetic diversity due to the bottleneck effect, is also
related to the activity of transposons that can create new variations and diversity. Examples of
different species are given
Age determination of banded murex Hexaplex trunculus using statolith reading method
No full textU diplomskom radu se koristila analiza mikrostrukture statolita za određivanje starosti kvrgavog volka Hexaplex trunculus (Linnaeus, 1758) (Gastropoda: Muricidae) na području istočnog srednjeg Jadrana. Statociste su vrećaste strukture i ključni organi za ravnotežu kod mekušaca, a unutar njih se nalaze tvrde vapnenaste strukture zvane statoliti koji su korisni za direktnu procjenu starosne strukture istraživane populacije. Tijekom istraživanja obrađena je 91 jedinka, raspona dužine kućice (SL) od 37,53 do 96,51 mm, mase tijela (BW) između 6,34 i 95,04 g te raspona promjera statolita (SD) od 0,23 mm do 0,39 mm. Procijenjena starost volaka je iznosila od 3 do 8 godina (N = 81). Dužinsko-maseni odnos je pokazao pozitivni alometrijski rast za mužjake (b = 3,1) te negativni alometrijski rast za ženke (b = 2,9). Između mužjaka i ženki nije utvrđena statistički značajna razlika u dužini kućice kao ni u masi tijela, dužini i širini zavoja kućice, kao ni kod ukupne dužine aperture, dužine aperture niti dužine sifonalnog kanala. Gore navedeno ukazuje da kod volka ne postoji sekundarni spolni dimorfizam. Rezultati rada mogu poslužiti za daljnja istraživanja starosne strukture jadranskog volka.In this thesis the analysis of statolith microstructure was used to determine the age of the banded murex Hexaplex trunculus (Linnaeus, 1758) (Gastropoda: Muricidae) in the eastern central Adriatic. Statocysts are saccular structures, key organs for balance in mollusks, and within them are hard calcareous structures called statoliths that are useful for direct assessment of the age structure of the studied population. During this research 91 individuals were sampled, with shell length (SL) range from 37.53 to 96.51 mm, the body weight between 6.34 and 95.04 g and statolith diameter (SD) range from 0.23 mm to 0.39 mm. The estimated age of whelks ranged from 3 to 8 years (N = 81). The length-weight relationship showed positive allometric growth for males (b = 3.1), while negative allometric growth was recorded for females (b = 2.9). No statistically significant difference was found between males and females in the length of the shell, nor in body weight, spire length and width, nor in the total length of the aperture, the length of the aperture or the length of the siphonal canal. All of the above indicates that there is no secondary sexual dimorphism in the whelks. The results of this work can be used for further research into the age structure of the adriatic banded murex
Sediments and sedimentation changes at one station in eastern part of the Kaštela bay
No full textU ovom su diplomskom radu predstavljeni rezultati uzorkovanja A i B jezgre srpanjskog i
prosinačkog razdoblja 2012. godine na istočnom dijelu Kaštelanskog zaljeva. Obrađeno je 65
uzoraka sedimenta čime se ustanovilo da na istraživanoj postaji prevladava taloženje čestica
veličine silta (51,51± 6,32%) i gline (37,43 ± 7,87%). Prevladavanje vrlo loše sortiranog
sedimenta ukazuje na različito podrijetlo (terigeno i biogeno) istaloženih čestica u sedimentu
koje su podjednakim udjelom karbonatne i nekarbonatne komponente (49,12 ± 4,86%
karbonata). Prema Shepardovoj klasifikaciji najzastupljenija je glinoviti silt, a prema Folkovoj
klasifikaciji mulj. Ustanovljene promjene duž jezgara sedimenta, kao i između njih, upućuju
na postojanje tri ekološka uvjeta koji upućuju osim na miran okoliš u kojem su povremeno
prisutni bentički organizmi i na antropogeni utjecaj s pretaloživanjem sedimenta.The thesis presents the results of A and B core samplings done in the eastern part of Kaštela
Bay in July and December 2012. From 65 processed sediment samples it was determined that
precipitation of silt particles (51.51 ± 6.32%) and clay particles (37.43 ± 7.87%) prevalied in
the examined station. Prevalence of very poorly sorted sediments indicated different origins
(terrigenous and biogenic) of precipitated particles in the sediments that are equally made of
carbonated and uncarbonated components (49.12 ± 4.86%). According to the Shepard
classification, clay silt is most common, and according to Folk classification the most
common is mud. The changes along the cores, as well as between them, indicated existence of
three ecological conditions what showed not only that there is a stable enviroment where
bentic organisms are occasionally found but also an antropological impact with precipitation
of sediment
Comparative nutrition analysis of native oyster Ostrea edulis and invasive oyster species Magallana gigas
No full textPacifička kamenica Magallana gigas (Thunberg, 1793) je vrsta koja se pojavila u Jadranskom moru krajem 1970-ih. Iako se uzgaja u ostatku Europe, u istočnom Jadranu se ne uzgaja te se smatra invazivnom vrstom. Pacifička kamenica prisutna je u velikoj brojnosti na području Limskog zaljeva koji predstavlja jedno od najvažnijih područja za uzgoj kamenice Ostrea edulis Linnaeus, 1758 i dagnje Mytilus galloprovincialis Lamarck, 1819. Utjecaji koje pacifička kamenica može imati na autohtone vrste u smislu kompeticije za hranu do sada nisu istraživani na ovom području, stoga je cilj ovog diplomskog rada bio pružiti prve komparativne rezultate ishrane vrsta M. gigas i O. edulis. In situ istraživanje fizioloških parametara je provedeno u travnju i kolovozu 2018. godine, dok je analiza sadržaja želudca provedena sezonski (veljača, svibanj, kolovoz i studeni 2018. godine). Rezultati in situ eksperimenta upućuju na preklapanje hranidbene niše kod dvije istraživane vrste u uvjetima koji vladaju u Limskom zaljevu. Analiza sadržaja želudca pokazala je da vrste M. gigas i O. edulis kao dodatni izvor hrane koriste zooplankton. Najbrojnije pronađene skupine zooplanktona u želudcima kod obje vrste bile su ličinke školjkaša i kopepodi. Kod vrste O. edulis broj pronađenih ličinki školjkaša najveći je do sad zabilježen u literaturi te je u jednoj odrasloj jedinki pronađeno 720 ličinki školjkaša, dok je kod vrste M. gigas on bio nešto manji i iznosio je 443 ličinke. Rezultat ovog istraživanja potvrdio je visoki stupanj preklapanja ishrane istraživanih vrsta te visoku stopu predacije ličinačkih stadija školjkaša kod obje istraživane vrste.Pacific oyster Magallana gigas (Thunberg, 1793) appeared in the Adriatic Sea in the late 1970s. Although it is cultivated around Europe, in the eastern Adriatic Sea this species was not introduced to the aquaculture, and it is considered invasive. The wild population of the Pacific oyster is present in great abundance in the Lim Bay, which is one of the most important aquaculture sites in the Adriatic Sea. In the Lim Bay, only two bivalve species are cultivated: oyster Ostrea edulis (Linnaeus, 1758) and mussel Mytilus galloprovincialis (Lamarck, 1819). In this area, there is no information about possible effects that the Pacific oyster could have on native species, which can be expressed through the competition for food. Therefore, the main objective of this thesis was to provide a comparative study of feeding habits of two oyster species, M. gigas and O. edulis. In situ experiments of different physiological parameters were carried out in April and August 2018 while stomach content analysis was carried out during each season (February, May, August and November 2018). Results of in situ experiments suggested an overlap of the food niche between two investigated species under the conditions prevailing in Lim Bay. Stomach content analysis showed that both oyster species used zooplankton as an additional food source. The most abundant zooplankton prey groups found in both species were bivalve larvae and copepods. Furthermore, numbers of bivalve larvae found in an adult O. edulis was 720 larvae, which is so far the highest recorded for any bivalve species, while the maximum number of bivalve larvae in the stomach of M. gigas was 443 larvae. Results of this research confirmed a high degree of feeding niche overlap between M. gigas and O. edulis. Furthermore, this study revealed a high degree of larviphagy in both oyster species
Bycatch of non-target species in longline fisheries
No full textParangali su udičarski ribolovni alati koji se koriste u svim morima svijeta te su karakteristični po niskoj stopi odbacivanja ulova. Ipak, obzirom na razmjere njihove upotrebe, nerijetko se u njihovim lovinama pronalaze različite neciljane lovine poput morskih pasa, sisavaca, kornjača i ptica. Kako bi se smanjio udio neželjenih vrsta u ulovu parangala koriste se razne metode poput upotrebe kružnih udica umjesto tradicionalnih udica „J“ oblika, noćno ili podvodno bacanje parangala, bojanje mamca plavom bojom te korištenje tori užadi. U ovom radu je dan kratak opis poviše navedenih metoda.Longlines are hook-based fishing gears used in all world oceans. They are responsible only for a small fraction of global discards. However, some endangered and/protected groups of animals such as sharks, sea mammals, sea turtles and seabirds can often be found in their catches. To reduce the accidental bycatch of those organisms fishermen often use mitigation measures such as circle hooks, dyed baits, bird scaring devices - tori lines and night or underwater longline setting. This thesis describes the above mention methods of bycatch reduction in longline fishery
Genetic variability and population structure of the gilthead seabream Sparus Aurata (Linnaeus, 1758) in the easteran Adriatic sea
No full textPosljednjih godina zamijećeno je značajno povećanje ulova divlje komarče u istočnom dijelu Jadranskog mora. Smatra se kako ubrzani porast kaveznog uzgoja doprinosi povećanju populacija komarči kao posljedica bježanja iz kaveznih uzgojnih instalacija. S obzirom na izvjesnost križanja uzgojnih i prirodnih populacija, ukazala se potreba procjene razine introgresije uzgojnog genotipa u prirodnim populacijama komarče, za što je u ovoj studiji korišten standardizirani set od dvadeset i jednog neutralnog mikrosatelitnog lokusa i tri mikrosatelitna lokusa povezana s genima kandidatima (hormonom rasta, GH, prolaktinom, PRL, i proteinom modifikacije aktivnosti receptora 3, RAMP3). Analizirani uzorci divljih komarči su ukazali na promjene genetske strukture unutar istraživanog akvatorija u godinama uzorkovanja te smanjenu genetsku povezanost s juvenilnim jedinkama i divljim jedinkama uzorkovanim u blizini uzgajališta tuna, što upućuje na njihov privremeni boravak na lokacijama uzorkovanja duž istočnog Jadrana. Nasuprot tome, genetska analiza uzorkovanih adultnih jedinki oko uzgajališta tuna pokazuje značajnu povezanost s mlađi obližnjeg priobalja, sugerirajući da uzgajališta mogu djelovati kao potencijalna mrijestilišta, na što upućuju i rezultati razvijenog modelskog sustava Roms-Ichthyop. U predmetnoj studiji je razvijena i genetska baza divljih i uzgojnih genotipova komarče istočnog Jadrana, što predstavlja značajan resurs i alat za uspješnu identifikaciju podrijetla jedinki kao neophodan korak u izradi kvalitetne strategije upravljanja ribljim prebjezima iz kaveznih sustava.Over the last few years, a significant increase of wild gilthead seabream in fisheries landings have been documented in coastal areas of the eastern Adriatic Sea. It has been suggested that rapid expansion of sea-cage farming contributes to increase of seabream populations through aquaculture escapes. The aim of this research was to assess the population genetic structure of wild and farmed populations along the eastern Adriatic coast and to investigate the impact of genetic introgression of escaped farmed seabream to wild seabream populations. To this end, a set of 21 neutral microsatellites and 3 microsatellites linked to candidate genes was used (growth hormone, GH, prolactin, PRL, receptor activity modifying protein 3, RAMP3). Wild adults demonstrated changes in genetic structure within basin in the respective sampling years and reduced connectivity with wild offspring, suggesting their temporal residency within the sampling areas of the eastern Adriatic. On the contrary, we observed a strong connection of wild seabream associated with tuna farming sites and offspring from the nearby nursery grounds indicating that the surroundings of tuna sea-cage farms could function as potential spawning grounds, which was also suggested by the Roms-Ichthyop model. A genetic database of wild and farmed gilthead seabream's genotypes was developed during the course of this study. This represents an important resource and a prerequisit for successfull identification of the animal origin as a necessary step in establishing a genetic-based escapes management startegy to control further erosion of genetic integrity
Genetic diversity of the European squid Loligo vulgaris and cuttlefish Sepia officinalis in the Mediterranean sea
No full textSipa Sepia officinalis i lignja Loligo vulgaris su komercijalno vrlo važne vrste u Sredozemnom moru i Jadranu. Populacije sipe su u pojedinim dijelovima Sredozemnoga mora pokazale veću ili manju diferencijaciju. Na oblikovanje genetičke strukture populacija sipe su uvelike kroz povijest utjecale klimatske promjene zajedno sa podizanjem razine mora te su se razlike stvarale i zbog hidrogeografskih obilježja. U Sredozemnom moru je uočena diferencijacija populacija sipe u odnosu na Atlantik, najčešće povezana s prekinutim protokom gena oko Gibraltarskih vrata i Almerijsko-Oranskom frontom, a identificiran je i izdvojeni stok specifičan za Egejsko i Jonsko more. Za razliku od sipe, struktura populacija lignje L. vulgaris je slabije proučena i nema ciljanih studija ove vrste preko cijelog Sredozemnog mora. U Jadranskom moru prema trenutnim istraživanjima postoji jedna povezana panmiktična populacija za svaku vrstu. Za L. vulgaris uočena i očekivana heterozigotnost te broj alela su bili konzistentno visoki i ujednačeni između svih uzoraka u Jadranu. Ovi parametri su bili nešto niži kod sipe S. officinalis.Cuttlefish Sepia officinalis and squid Loligo vulgaris are commercially very important species in the Mediterranean and Adriatic Sea. Populations of cuttlefish have shown greater or lesser differentiation in certain parts of the Mediterranean. Populations have been largely affected by the history of climate change along with rising sea levels, also these differences have been created due to the hydrogeographical characteristics. Differentiation of Mediterranean cuttlefish populations in respect to Atlantic has been observed, most commonly associated with limited gene flow around the Gibraltar Strait and the Almeria-Oran Front. An isolated stock specific to the Aegean and Ionian Sea has also been identified. In contrast to the cuttlefish, the structure of L. vulgaris population has been less studied and there are no studies of this species across the Mediterranean. In the Adriatic, according to current research, there is one panmictic homogenous population for each species. Observed and expected heterozygosity and the number of alleles were consistently high and uniform between all samples for L. vulgaris in the Adriatic. These parameters were slightly lower in cuttlefish S. officinalis
Catch comparison of beach seines targeting picarel with mesh size 12 and 24 mm in the area of Hvar island
No full textU ovom radu napravljena je analiza ulova i prilova obalne potegače za lov gire veličine oka 12 i 24 mm, na području otoka Hvara tj. Paklinskih otoka. Tijekom jednomjesečnog istraživanja napravljeno je ukupno 20 potega, po 10 sa svakom mrežom, te analizirano 8856 jedinki riba i glavonožaca ukupne mase 205,9 kg. U ulovu mrežom veličine oka 12 mm zabilježeno je 39 vrsta riba i 2 vrste glavonožaca, među kojima je dominirala gira oblica (Spicara smaris) sa 76,7% od ukupnog ulova, te bukva (Boops boops) s 12,26%. U mreži veličine oka 24 mm našlo se 42 vrste riba i 3 vrste glavonožaca, gdje su također dominirale gira oblica sa 62,73% i bukva sa 14,10% ukupnog ulova. Mrežom veličine oka 24 mm lovljen je manji broj nezrelih primjeraka najzastupljenijih vrsta, npr. zabilježena je samo jedna nezrela jedinka gire oblice od njih 2664, dok je kod mreže veličine oka 12 mm nezrelo bilo 239 jedinki od njih 3535.This thesis analysed the catches and by-catches of beach seine for catching picarel with mesh size 12 i 24 mm in the area of the island of Hvar. During the research period a total of 20 hauls were analysed, 10 with each net, and 8856 specimens of fish and cephalopods were recorded, with total weight of 205.9 kg. In the catches of beach seine with 12 mm mesh size, 39 species of fish and two species of cephalopods were recorded, and dominant species were picarel (Spicara smaris) with 76.7% and bogue (Boops boops) with 12.26% of the total catch. In the catches of beach seine with 24 mm mesh size, 42 species of fish and 3 species of cephalopods were found, and dominant species were also picarel with 62.73% and bogue with 14.10% of the total catch. In the 24 mm mesh very low numbers of immature specimens of the most common species were caught. For example, only one immature picarel specimen out of 2664 was recorded for 24 mm mesh size, compared to 239 immature specimens out of 3535 for 12 mm mesh size
The effects of herbal extracts in growth of bacterial pathogens in food
No full textU ovom radu predstavljeni su rezultati utjecaja kombiniranih biljnih ekstrakata (češnjak + ružmarin, češnjak + klinčić) na rast patogenih bakterija (Listeria monocytogenes i Staphylococcus aureus) i ukupnih mezofilnih bakterija (MEZ) u ribljem burgeru tijekom 10 dana pohrane na 4°C. Burgeri su proizvedeni od mesa svježeg lubina iz uzgoja (Dicentrarchus labrax) i pišmolja (Merlangius merlangus) u omjeru 60:40 s dodatkom soli od 1%. Prethodno liofilizirani biljni ekstrakti dodani su u mljeveno meso ribe i to u slijedećim kombinacijama: i) kontrolni uzorak sa 1% soli bez dodataka, ii) uzorak s 1,5% češnjaka i 0,5% ružmarina; iii) uzorak s 1,5% češnjaka i 0,5 % klinčića. Formirani burgeri inokulirani su bakterijama, pakirani u vakuum i pohranjeni na 4°C kroz 10 dana tijekom kojih je praćen rast bakterija. Obje mješavine biljnih ekstrakata pokazale su se najuspješnijima u inhibiciji rasta ukupnih aerobnih mezofilnih bakterija u uzorcima inokuliranima bakterijom S. aureus, gdje su umanjile ukupan broj bakterija sve do 8. dana skladištenja. Obje mješavine pokazale su se jednako uspješne i u inhibiciji rasta L. monocytogenes, mješavina češnjaka i ružmarina inhibirala je bakterijski rast kroz 4 dana skladištenja, a mješavina češnjaka i klinčića tijekom 6 dana. Kombinacija češnjaka i klinčića inhibirala je bakterijski rast S. aureus tijekom 4 dana skladištenja. Obje mješavine biljnih ekstrakata inhibirale su dva dana rast ukupnih aerobnih mezofilnih bakterija u uzorcima inokuliranima bakterijom L. monocytogenes, a mješavina češnjaka i klinčića pokazala se djelotvornijom.This paper presents the results of the effects of combined plant extracts (garlic + rosemary, garlic + clove) on the growth of pathogenic bacteria (Listeria monocytogenes and Staphylococcus aureus) and total mesophilic bacteria (MEZ) in fish burgers over 10 days. The burgers were made from farmed fresh European seabass (Dicentrarchus labrax) and whiting (Merlangius merlangus) in 60:40 ratio with the addition of 1% salt. The previously lyophilized plant extracts were added to the minced meat in the following combinations: i) control sample with 1% salt without additives, ii) sample with 1.5% garlic and 0.5% rosemary; iii) sample with 1.5% garlic and 0.5% cloves. The formed burgers were inoculated with bacteria, vacuum packed and stored at 4 °C for 10 days during which bacterial growth was monitored. In the samples with plant extracts inoculated with S. aureus inhibition of total aerobic mesophilic bacteria was achieved and the total number of bacteria remained lower than the control samples over 8 days of storage. Both mixtures were equally successful in inhibiting the growth of L. monocytogenes. The mixture of garlic and rosemary inhibited bacterial growth during 4 days of storage, and the mixture of garlic and cloves over 6 days. The combination of garlic and clove inhibited bacterial growth of S. aureus over 4 days. The growth of total aerobic mesophilic bacteria in the samples inoculated with L. monocytogenes was inhibited by both combinations of plant extracts over 2 days of storage, and the garlic-clove mixture proved to be more effective