Repository of the Department of Marine Studies at the University of Split
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Influence of abiotic factors on the mussel growth near sea bass cages
No full textU ovom su radu predstavljeni rezultati mjerenja morfoloških karakteristika dagnje Mytilus galloprovincialis na dva lokaliteta, u blizini kaveznog uzgoja lubina. Mjerenja su odrađena tijekom 3 mjeseca (listopad,studeni i veljača) na Prokljanskom jezeru i u Srednjem kanalu. Razlike u rastu dagnje između lokaliteta uvjetovane su abiotskim čimbenicima, ponajviše salinitetu. Cilj rada je bio utvrditi utjecaj abiotskih čimbenika na prihvat i rast dagnje te utjecaj intenzivnog uzgoja ribe na rast dagnje. U tu svrhu mjerena su morfološka obilježja (dužina, visina, širina i masa) dagnje na dvije lokacije, neposredno u blizini kaveza s ribom. Prosječna izmjerena dužina, širina i masa (ukupna masa i masa mokrog tkiva) dagnje nakon 6 mjeseci je bila veća kod dagnje iz Prokljanskog jezera, dok je prosječna visina i masa ljušture bila veća kod dagnje iz Srednjeg kanala. Identificirana je statistički značajna razlika između postaje Raslina i Ždrelac u pogledu indeksa kondicije školjkaša neovisno o vremenu (p<0,001). Rezultati pokazuju brži rast dagnji iz Prokljanskog jezera nakon spuštanja kolektora na dubinu od 6-7 m, gdje je salinitet stabilan.This thesis presents the results of measuring morphological characteristics of the mussel Mytilus galloprovincialis at two sites. Measurements were made during 3 months (October, November and February) on Lake Prokljan and in the Middle Channel. The difference between the localities is represented by abiotic factors, mostly salinity. The aim of this thesis is to determine the influence of abiotic factors on the acceptance and growth of mussels and the influence of intensive fish farming on mussel growth. To this end, morphological characteristics (length, height, width and weight) of mussels were measured at two locations, near fish cages. The average measured length, width and weight (total weight and wet tissue weight) of mussels after 6 months was higher in mussels from Prokljan Lake, while the average height and weight of the shell was higher in mussels from the Middle Channel. A statistically significant difference was identified between Raslina and Ždrelac stations in terms of shellfish fitness index regardless of time (p<0.001). The results show faster growth of mussels in the Prokljan Lake after lowering the collector to a depth of 6-7 m, where the salinity is stable
Structure of fish communities on vertical coralligenous habitats in the Hvar channel
No full textOva disertacija se sastoji od pet objedinjenih radova i zasniva se na istraživanjima ribljih naselja na podvodnim vertikalnim koraligenim grebenima tehnikom podvodnog vizualnog cenzusa (metoda kvadrata i metoda transekta) i ulovnim neribolovnim tehnikama. Podaci su se prikupljali na četiri lokacije u Hvarskom kanalu tijekom razdoblja od pet godina. Najveća dubina ronjenja prilikom istraživanja je bila 65 m, a uz korištenje tehnike dubokih dekompresijskih zastanaka osim komprimiranog zraka za disanje korišteni su i Nitrox50 i Trimix mješavine plinova. Prvi rad obuhvaća kvantitativno uzorkovanje metodom kvadrata od površine do 45 m dubine te je prikupljeno 220 kriptobentoskih i 61 epibentoska jedinki. Kriptobentoskim naseljima riba dominirala je obitelj glavoča, kako po biološkoj raznolikosti (> 60% svih vrsta) tako i po brojnosti (> 90% svih primjeraka). Vrste koje su se ranije smatrale rijetkim bile su prisutne, neke čak i brojne u ovom istraţivanju. Drugi rad opisuje prvi put korištenu kvantitativnu metodu uzorkovanja za duboku kriptobentosku i epibentosku ihtiofaunu pomoću Trimix mješavina plinova koja je provedena na dubini od 57 do 62 m. Prikupljeno je 16 primjeraka iz četiri vrste riba, tj. tri vrste glavoča i jedna babica. Dvije od sakupljenih vrsta, Thorogobius macrolepis i Vanneaugobius dollfusi su do tada smatrane rijetkima, usljed veoma malo zabiljeţenih nalaza u svijetu. U trećem radu testirane su dnevne razlike u sastavu naselja epibentoskih i kriptobentoskih riba. Ukupno je zabiljeţeno 27 kriptobentoskih i epibentoskih vrsta riba. Kombinirani rezultati sugeriraju da su kriptobentoska riblja naselja većinom sastavljena od stalnih stanovnika skrivenih prostora s veoma malim dnevnim promjenama. Četvrti rad opisuje novu metodu podvodnog vizualnog cenzusa prikladnu za dublje vertikalne podvodne grebene.
Nazvana je Deep Vertical Transect (DVT) i rađena je na dubinama od površine mora do 50 m. U istraživanju je ukupno zabilježena 51 vrsta riba, pri čemu je 41 vrsta kategorizirana kao stalni stanovnik koraligenog grebena, dok se 10 vrsta smatra povremenim stanovnicima. U transektima ispod termokline opaţen je najmanji broj vrsta što ukazuje na temperaturu kao jedan od najvažnijih parametara koji utječe na dubinsku raspodjelu ribljih naselja u ljetnom razdoblju. Peti rad opisuje metodu podvodnog vizualnog cenzusa zasnovanu na korištenju transekta te podvodnog skutera uz uporabu ronilačkih aparata zatvorenog kruga disanja. Tri varijable okoliša, dubina, životinjski pokrov i istočni položaj grebena, identificirane su kao vrlo značajne za pojavljivanje vrsta, ali značajne varijable bile su i nagib, morsko dno s pukotinama i šupljinama (prostorna heterogenost) te podloga s više ili manje glatkom površinom.This dissertation consists of 5 combined papers and is based on research of fish communities on underwater vertical coralligenous reefs using the underwater visual census technique (square method and vertical transect method) and catching non - fishing techniques. Data were collected at 4 locations in the Hvar Channel over a five years period. The maximum diving depth during the research was 65 m, and with the use of the technique of deep decompression stops, in addition to compressed breathing air, Nitrox50 and Trimix gas mixtures were also used. The first paper includes quantitative sampling by the method of squares from the surface to a depth of 45 m, and 220 cryptobenthic and 61 epibenthic individuals were collected. Cryptobenthic fish communities were dominated by the gobiid family, both in terms of biological diversity (> 60% of all species) and in terms of abundance (> 90% of all samples). Species previously considered as rare were present, some of them even numerous in this locality. The second paper describes the first-used quantitative sampling method for deep cryptobenthic and epibenthic ichthyofauna using Trimix gas mixtures conducted at a depth of 57 to 62 m. Two of the collected species, Thorogobius macrolepis and Vanneaugobius dollfusi, were previusly considered rare in the Mediteranean, due to the very few reported records. In the third paper, daily differences in the composition of cryptobenthic and epibenthic fish populations were tested. A total of 27 cryptobenthic and epibenthic fish species were recorded. The results suggest that cryptobenthic fish settlements are mostly composed of permanent residents with very little daily change. The fourth paper describes a new method of underwater visual census suitable for deeper vertical underwater reefs. We named it as Deep Vertical Transect (DVT) and we performed it at depths of up to 50 m. The study recorded a total of 51 fish species, with 41 species categorized as permanent inhabitant of the coralligenous reef, while 10 species are considered occasional residents. In the transects below the thermocline, the smallest number of species was observed, which indicates temperature as one of the most important parameters influencing the depth distribution of fish settlements in the summer period. The fifth paper describes the method of underwater visual census based on the use of a transect and an underwater scooter with the use of closed-circuit diving apparatus - CCR rebreather. Three environmental variables, depth, zoocover and eastern reef position, were identified as very significant for species occurrence, but significant variables were also slope, seabed with cracks and cavities, and substrate with more or less smooth surface
Bioactive compounds of marine origin
No full textU ovom radu opisani su odabrani biološki aktivni spojevi izolirani iz morskih organizama i mikroorganizama čija je aktivnost istražena, a primjena korisna u mnogim industrijama. Mnogi od opisanih spojeva postali su nezamjenjivi nutraceutici i farmaceutici. Od bioaktivnih spojeva istraženih u ribi i rakovima te njihovim nusproizvodima višestruko nezasićene masne kiselina te njihova uloga i primjena u zdravlju ljudi su među najinteresantnijima. Nadalje rad opisuje ulogu i primjenu kolagena, bioaktivnih peptida te hitina i hitozana iz održivih izvora. Dodatno rad opisuje veliki potencijal beskralježnjaka (spužve), algi i morskih mikroorganizama kao izvora biološki aktivnih spojeva koji imaju brojne biološke aktivnosti, među kojima antimikrobnu, antioksidacijsku, antitumornu i druge.The thesis describes selected biologically active compounds isolated from marine organisms and microorganisms whose activity has been well investigated for the application in different industries. Many of the described compounds have become irreplaceable nutraceuticals and pharmaceuticals. The polyunsaturated fatty acids from fish and crustaceans, and their by-products as well as their role and applications in human health are among the most interesting and investigated. Furthermore, the paper describes the role and applications of collagen, bioactive peptides, and chitin and chitosan from sustainable marine sources. The great potential of invertebrates (sponges), algae and marine microorganisms as sources of biologically active compounds with numerous biological activities, including antimicrobial, antioxidant, antitumor, and others, has also been reviewed
Bio-ecological characteristic of Ommastrephes caroli (Cephalopoda: Ommastrephidae) in the Eastern Adriatic Sea
No full textLeteći lignjun pripada veoma rijetkim glavonošcima Jadranskog mora čija je biologija gotovo
nepoznata. 'Leteći lignjuni' su naziv dobili zbog svoje sposobnosti iskakanja iz vode, jer mlade
juvenilne jedinke kad bježe od predatora često iskaču iznad površine mora. Do danas, svega su
četiri prijavljena zapisa ove vrste u Jadranu. U rujnu 2020. godine ukupno su prikupljene 23
juvenilne jedinke letećeg lignjuna na području srednjeg istočnog Jadrana, i to na području otoka
Palagruže (N = 14), otoka Jabuke (N = 1) te Korčulanskog kanala (N = 8), čime se otvorila
mogućnost za bolje upoznavanje biologije i genetičke raznolikosti ovih rijetkih glavonožaca
Jadrana. S obzirom da se radi o malom broju jedinki, u ovom radu su opisane preliminarne
morfometrijske značajke tijela i kljuna te dužinsko-maseni odnos koji je pokazao izometrijski
rast prikupljenih lignjuna. Raspon dorzalne dužine plašta lignjuna je bio od 65 do 152 mm, a
masa tijela od 7,6 do 89,8 g. Starost prikupljenih jedinki određena je metodom očitavanja
statolita te je procijenjena srednja vrijednost starosti iznosila 49,3 dana. Filogenetska analiza
nukleotidne sekvence mitohondrijskog gena za podjedinicu I citokrom c oksidaze (COI)
pokazala je da prikupljeni uzorci pripadaju vrsti Ommastrephes caroli (Furtado, 1887) koja je
nedavno, uz preostale tri vrste, prepoznata unutar roda Ommastrephes koji se dugo godina
smatrao monotipskim kozmopolitskim rodom s diskontinuiranom rasprostranjenošću.The neon flying squids belong to a very rare cephalopods of the Adriatic Sea whose biology is
almost unknown. 'Flying squids' got their name because of the ability to jump out of the water,
as young juvenile individuals often jump above the sea surface when escaping predators. To
date, there are only four reported records of this species in the Adriatic. In September 2020, a
total of 23 juveniles of flying squid were collected in the central eastern Adriatic, in the area of
the island of Palagruža (N = 14), the island of Jabuka (N = 1) and the Korčula Channel (N = 8),
thus providing the opportunity to better study biology and genetic diversity of these rare
cephalopods of the Adriatic. Based on a small sample size, this paper describes the preliminary
morphometric characteristics of the squid body and beak, as well as the length-weight
relationship that showed isometric growth. Dorsal mantle length ranged from 65 to 152 mm,
while body weight ranged from 7.6 to 89.8 g. The age of the collected individuals was
determined by the statolith reading method, and the estimated mean age was 49.3 days.
Phylogenetic analysis using nucleotide sequence of the mitochondrial cytochrome c oxidase
subunit I (COI) gene showed that collected samples belong to the species Ommastrephes caroli
(Furtado, 1887) which was recently, along with the remaining three species, recognized within
the genus Ommastrephes d'Orbigny that has been for many years considered a monotypic
cosmopolitan genus with a discontinuous distribution
ASSOCIATIONS BEWTEEN FISHES AND LUMINESCENT BACTERIA
No full textLuminiscentne bakterije s ribama stvaraju mutualističke fakultativne ili obligatne zajednice od
kojih obje vrste imaju koristi. Bakterije u zajednici dobivaju zaštitu i hranjive tvari potrebne
za rast i razvoj, dok ribe dobivaju svjetlo koje koriste u svrhu obrane od predatora, privlačenja
plijena te intraspecijsko signaliziranje. U ovom radu opisane su zajednice koje stvaraju
luminiscentne bakterije s ribama porodice Anomalopidae i Leiognathidae te reda
Lophiiformes. Ribe porodice Anomalopidae imaju subokularni svjetleći organ u kojem se
nalaze bakterije koje su u obligatnom odnosu s ribom domaćinom. Vrste reda Lophiiformes
također su u obligatnim zajednicama s luminiscentnim bakterijama no njihov svjetleći organ
se nalazi se na području glave. Ribe iz porodice Leiognathidae su u fakultativnom odnosu s
luminiscentnim bakterijama, a skladište ih u svjetlećem organu koji obavija jednjak.Luminescent bacteria with fish create mutualistic facultative or obligatory associations from
which both species benefit. Bacteria in the association recive the protection and nutrients
needed for growth and development, while fish recive light that they use for the purpose of
defending themselves from predators, attracting prey and intraspecific signaling. This paper
describes associations that luminescent bacteria create with fish of the family Anomalopidae
and Leiognathidae and the order Lophiiformes. Fish of the family Anomalopidae have a
suboccular light organ that contains bacteria that are in a obligatory association with the host
fish. Species of the order Lophiiformes are also in obligatory association with luminescent
bacteria but their light organ is located on the head area. Fish from family Leiognathidae are
in a facultative relationship with luminescent bacteria, and store them in a light organ that
surrounds the esophagus
Utilization and usability of biohydrogen from microalgae
No full textNapretkom znanosti i tehnologija pokazuje se potreba za obnovljivim izvorima energije npr.
vjetra, vode, Sunca te njihove upotrebe i što veće iskoristivosti s manjim gubitcima. Biovodik
je jedan od obnovljivih izvora energije koji se dobiva kao proizvod biofermentacije,
biofotolize, bioelektrokemijskih sustava, različito obrađenom biomasom a i kao proizvod
metabolitičkih procesa organizama poput mikroalgi. Može se koristiti za razne svrhe kao u
automobilskoj industriji, kemijskoj industriji i gorivim člancima međutim postoji problem
iskoristivosti kad je namijenjen za opsežnija i veća područja djelovanja. Problem iskoristivosti
biovodika iz mikroalgi se pokušava riješiti boljom selekcijom kultura, modifikacijom
bioreaktora te metaboličkim inženjeringom. U radu je napravljen pregled poboljšanja
iskoristivosti biovodika iz mikroalgi.With advancement in science and technology, necessity for sustainable energy sources like
wind, water, Sun is growing just like their maximum usage with minimal losses. Biohydrogen
is also one of sustainable energy sources as a product of biofermentation, biophotolysis,
bioelectrochemical systems, processed biomass or from metabolic processes of organisms like
microalgae. It can be used in car industry, chemical plants, fuel cells but it generally has a
problem of usability. That kind of problem is tackled by better culture selection, bioreactor
modifications and metabolic engineering of biohydrogen specialists. This thesis presents an
overview of how to improve usability of biohydrogen from microalgae
Biological diversity on shellfish larvae collectors at the Cetina estuary
No full textU radu je prikazano istraživanje zajednice školjkaša na sakupljačima ličinki školjkaša postavljenih na tri lokacije područja ekološke mreže Natura 2000 Ušće Cetine (HR3000126) s po tri replike na dubinama od 2, 4, 6, 8 i 10 m. Sakupljači ličinki školjkaša su postavljeni s ciljem prikupljanja ličinki dugoživućeg, strogo zaštićenog i kritično ugroženog, sredozemnog endemskog školjkaša plemenite periske Pinna nobilis Linnaeus 1758. Nakon odležavanja od pet mjeseci determinirano je prisutvo ukupno 11 porodica sa 16 vrsta školjkaša te prikupljenom jednom invazivnom vrstom školjkaša Pinctada imbricata te jednom juvenilnom jedinkom kritično ugrožene vrste P. nobilis duljine 12 mm.The thesis presents the research on a shellfish community present on a shellfish larvae collector from 3 locations inside of ecological network Natura 2000 Cetina river (HR3000126). Three replicates of the collectors were installed on different depths: 2, 4, 6, 8 and 10 m. Main goal of setting up larvae collectors was gathering larvae of long lived, severly protected and critically endagered Mediterranean endemic shellfish Pinna nobilis Linnaeus 1758. After five months, the presence of a total of 11 families with 16 species of shellfishes including one invasive species Pinctada imbricata and one juvenile individual of the critically endangered species P. nobilis (12 mm in length) was determined
The importance of electroreception in prey capture behaviour of elasmobranchs
No full textElektrorecepcija je senzorna modalnost koja omogućava hrskavičnjačama detektiranje bioelektričnih polja drugih organizama. Za detekciju su odgovorni ampularni receptori koji su smješteni na glavi ili prsnim perajama hrskavičnjača. Razlikujemo pasivnu i aktivnu elektrorecepciju. Kod pasivne elektrorecepcije jedinke koriste svoje sposobnosti prijema impulsa za detekciju plijena i za snalaženje u prostoru tj. orijentaciju. Kod aktivne elektrorecepcije jedinka se koristi elektrolokacijom kada životinja u svom okruženju generira električna polja i otkriva izobličenja u tim poljima pomoću elektroreceptorskih organa. Detekcija plijena bazirana je na dobro usmjerenim reakcijama same životinje zbog emisije bioelektričnog polja plijena koji je uglavnom skriven pod sedimentom. Što se tiče detekcije predatora pomoću elektrorecepcije, mogućnost otkrivanja opasnosti uočena je već u ranih razvojnih stadija embrija. Uslijed promjene električnih impulsa, embrij ima mogućnost minimizirati olfaktorne signale koji su upadljivi predatoru te se na taj način zaštititi.Electroreception is a sensory modality that allows elasmobranchs to detect the bioelectric fields of other organisms. Ampullary receptors located on the head or pectoral fins are responsible for detection. We can differentiate passive and active electroreception. In passive electroreception, the animal uses their ability to receive impulses to detect prey and to orientate themselves. In active electroreception, electrolocation is used when the animal generates electric fields and detects distortions in those fields using electroreceptor organs. Prey detection is based on well-directed reactions of the animal itself due to the emission of a bioelectric field of prey that is usually hidden under sediment. As for the detection of predators by electroreception, the possibility of detecting potential danger is already expressed in the early development of the embryonic stage. Due to the change of electrical impulses, the embryo has the ability to minimize olfactory signals that are noticeable to the predator and thus protect themselves
Seasonal distribution of larvae of benthic invertebrates in mereplankton of estuaries
No full textPelagične ličinke bentoskih beskralješnjaka čine značajan dio planktonskih zajednica u morima,
ali zbog kompleksne identifikacije i promjenjive morfologije kroz kratak period razvoja i danas
postoje mnoga neodgovorena pitanja u vezi s njihovim podrijetlom i ekologijom. Cilj je ovog
diplomskog rada bio utvrditi sezonsku raspodjelu, taksonomsku pripadnost i prisutne
morfotipove ličinki bentoskih beskralješnjaka u planktonu prijelaznih voda istočnog dijela
Jadranskog mora. Uzorkovanje zooplanktona je provedeno u kolovozu 2020. (ljeto), listopadu
2020. (jesen), veljači 2021. (zima) i travnju 2021. (proljeće), na jednoj postaji u estuariju
Zrmanje te na dvije postaje u estuariju rijeke Krke i delti Neretve, vertikalnim potezima
planktonske mreže promjera oka svile od 125 m. Tijekom mikroskopske obrade uzoraka,
ličinke su prebrojane do minimalnog ukupnog broja od 30 jedinki, dok je za grupe koje se
rijetko pojavljuju, pregledan cijeli uzorak. Dobiveni su rezultati pokazali da su na većini postaja
dominantno bile zastupljene ličinke mekušaca (Bivalvia i Gastropoda) u svim sezonama, uz
malobrojne izuzetke. Općenito, veći je broj različitih morfotipova ličinki zabilježen tijekom
ljeta. Sezonski karakter je ustanovljen za pojedine skupine (školjkaši, desetonožni rakovi,
mnogočetinaši) i očitovao se uglavnom u promjenama abundancija ličinki, a znatno manje u
prisutnosti/odsutnosti pojedinih grupa. Postaje u delti rijeke Neretve se donekle razlikuju od
ostala dva područja budući da ličinke bentoskih beskralješnjaka tijekom proljeća i ljeta imaju
najmanju abundanciju, dok su u jesen i zimu među najvišim vrijednostima.Pelagic larvae of benthic invertebrates represent a significant part of marine planktonic
communities, but due to difficult identification and variable morphology through the rapid
period of development, there are still many questions regarding their origin and ecology. The
aim of this thesis was to determine the seasonal distribution, taxonomic affiliations and
morphotypes of benthic invertebrate larvae in zooplankton communities of transitional waters
of the eastern Adriatic Sea. Zooplankton sampling was performed in August 2020 (summer),
October 2020 (autumn), February 2021 (winter) and April 2021 (spring), at one station in the
Zrmanja estuary and at two stations in the Krka estuary and in the Neretva delta, by vertical
hauls of a plankton net (silk mesh diameter 125 m). After processing the samples, the larvae
were counted to a minimum total of 30 individuals while for the rare groups, the whole sample
was examined. The obtained results showed that mollusc larvae (Bivalvia and Gastropoda) were
numerically predominant at most stations in all seasons, with only a few exceptions. In general,
a higher number of different larval morphotypes was present during the summer. Seasonal
character has been established for larvae of certain groups (bivalves, decapod crustaceans,
polychaetes), but it was manifested mainly in changes in the larval abundance, and much less
in the presence/absence of particular groups. The stations in the Neretva delta, however,
differed somewhat from the other two areas, having the lowest abundance during spring and
summer, and among the highest in autumn and winter
Preservatives in seafood
No full textRast svjetske populacije i ubrzan način života potaknuli su čovječanstvo na razvoj novih otkrića u svijetu prehrambene industrije. Zemlja je više plavi nego zeleni planet zbog čega ne čudi da najveći dio hrane za konzumaciju dolazi iz mora. Nažalost sva hrana morskog porijekla u svježem obliku ima kratak rok trajanja i to na niskim temperaturama. Kroz rad su opisani načini konzumacije proizvoda ribarstva, kvarenje i očuvanje istih uporabom konzervansa. Prikazana je i podjela konzervansa u tri skupine: prirodne, životinjske i umjetne. U svakoj skupini je obrađeno po nekoliko primjera konzervansa koji se koriste za proizvode ribarstva i za svakog je ukratko naveden način primjene i svrha. Uporaba konzervansa ima određena ograničenja, a njihove dozvoljene količine regulirane su zakonskim aktima. U radu je predstavljen zakonodavni sustav Republike Hrvatske i Europske unije te podjela konzervansa prema Ebrojevima.World population growth and accelerated lifestyles have encouraged humanity to develop new discoveries in the world of the food industry. The earth is more blue than a green planet which is why it is not surprising that most of the food for consumption comes from the sea. Unfortunately, all seafood in fresh form has a short shelf life. The paper describes the ways of consuming fishery products, spoiling and preserving them using preservatives. The division of preservatives into three groups is also presented: natural, animal and artificial. In each group, several examples of preservatives used for fishery products were described, and for each, the method of application and purpose were briefly stated. The use of preservatives has certain restrictions, and their permitted quantities are regulated by legal acts. The paper presents the legislative system of the Republic of Croatia and the European Union and the division of preservatives according to E-numbers