Repository of the Department of Marine Studies at the University of Split
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Associations between fishes and sea cucumbers
No full textU ovim radu se opisuju zajednice riba i morskih trpova. U morskim trpovima sklonište nalaze ribe iz potporodice Carapinae (strmorinci). Unutar ove potporodice su dva roda komenzalnih i parazitskih vrsta. Razna istraţivanja su pokazala da ove ribe od trpova dobivaju ne samo zaštitu već i hranu. Parazitske ribe roda Echiodon koje jedu gonade čine to direktno dok komenzalne vrste roda Carapus koriste trpa kao mamac, odnosno za privlačenje tenuis ličinki i juvenila u domaćina. Parazitske vrste mogu uzrokovati kastraciju zaraţenih trpova, ali zbog brzine regeneracije trpova štete se ne smatraju opasnim za trpa ili cjelokupnu populaciju. Za neparazitske vrste nisu zabiljeţeni nikakvi učinci na domaćina kada su strmorinci boravili unutar njihovih crijeva ili dišnih stabala, ali su otkrivene značajne štete na gonadama u slučajevima kada su ribe bile u domaćinovom celomu.In this paper assocoations of fishes and sea cucumbers are described. Fish species of the subfamily Carapinae (pearlfishes) find their shelter in sea cucumbers. This subfamily encompassestwo genera of commensal and parasitic species. Various researches have shown that these fishes obtain from their hosts not only protection but also food. While the parasitic fishes of the genus Echiodon eat their gonads, the commensal species of the Carapus genus use the sea cucumber as a bait to attract the tenuis larvae and juveniles to the host. Parasitic species can cause castration of the infected sea cucumbers but due to the regeneration rate these damages are not considered dangerous for the host or the entire population. When living in the intestines or respiratory tract of sea cucumbers no adverse effects on the hosts of nonparasitic pearlfishes were observed, while there is a significant damage on gonads in cases where the fish were in the coelom of the hosts
Epidemiology of Cryptosporidium spp. in bivalves under anthropogenic influence
Get PDFU ovom radu predstavljeni su rezultati istraživanja prisutnosti protozoarnog nametnika Cryptosporidium spp. sredozemne dagnje (Mytilus galloprovincialis) izložene antropogenom utjecaju, kao i učinkovitost pročišćavanja bakterije Escherichia coli iz dagnji smještenih u pokusnom sustavu za pročišćavanje Instituta za oceanografiju i ribarstvo u Splitu. Analizirane jedinke prikupljene su na uzgajalištu Stipan Jaz u Marini pokraj Trogira, postavljene u pergolare, te ostavljene dva dana na morskoj lokaciji izloženoj antropogenom izvoru mikrobiološkog onečišćenja. Istraživanje prisutnosti Cryptosporidium spp. dalo je negativne rezultate, na što su mogli utjecati različiti čimbenici (niska koncentracija ili nedostatak oocista prisutnih u moru, razrjeđenje oocista zbog slatkovodnog dotoka, kemijski i fizički čimbenici). Istraživanje koncentracije bakterije E. coli te učinkovitosti pročišćavanja dalo je očekivane rezultate. Koncentracija E. coli kod nepročišćenih dagnji netom stavljenih u sustav za pročišćavanje je bila visoka, što ukazuje na značajno mikrobiološko onečišćenje područja u kojem su dagnje bile postavljene, te učinkovitost dagnji u koncentriranju E. coli. Rezultati pročišćavanja pokazali su nagli pad koncentracije E. coli u prvih 12 sati pročišćavanja, nakon čega je slijedila blaga stagnacija tj. sporiji pad koncentracije E. coli nakon 24 i 48 sati pročišćavanja. Također je primijećeno da je koncentracija E. coli nakon 48 sati pročišćavanja smanjena na iznos manji od najmanje dozvoljene koncentracije za uzgojno područje A (≤ 230 E. coli/100 g tkiva i međuljušturne tekućine). Temeljem toga se može zaključiti da u specifičnim okolnostima Cryptosporidium spp. ne predstavlja rizik za infekciju čovjeka, a provedeni proces pročišćavanja omogućava uspješno uklanjanje E. coli iz dagnje.This paper presents the results of assessment of the protozoan Cryptosporidium spp. presence in the Mediterranean mussels (Mytilus galloprovincialis) exposed to anthropogenic influence, as well as the efficiency of purification of the bacterium Escherichia coli from mussels placed in the experimental purification system of the Institute of oceanography and Fisheries, Split. Analysed samples collected from the farming site Stipan Jaz in Marina close to Trogir were placed in plastic nets (pergolas) and left for two days at the marine location exposed to the anthropogenic source of microbiological contamination. Cryptosporidium spp. presence in the mussels showed negative results, which could have resulted from a variety of factors (low concentration or total absence of oocysts in the water column, reduction of oocysts due to freshwater flow, chemical and physical factors). In contrast, the concentration of E. coli bacteria and the efficiency of the treatment gave the expected results; the former was high in untreated mussels placed in the purification treatment system, indicating towards a significant microbiological contamination of the location under anthropogenic influence, and the capability of mussels to accumulate E. coli. Purification results showed strong decrease in E. coli levels in the first 12 hours of purification, after which a slow stagnation i.e. slower decrease in E. coli levels followed, after 24 and 48 hours of purification. Also, it has been noted that the concentration of E. coli after 48 hours has been reduced to the levels lower than the lowest permitted concentration for the farming site A (≤ 230 E. coli/100 g tissue and liquor). Based on this, it can be concluded that in specific conditions Cryptosporidium spp. does not represent a risk for human infection, while the applied purification process enables successful clearance of E. coli from the mussels
Traditional and modern technologies of marinating fish
No full textMariniranje je jedna od najstarijih kemijskih metoda konzerviranja kojom se dobivaju kiselkasti proizvodi, nježne teksture i ograničenog roka trajanja. Sastojci koji se koriste za konzerviranje su sol i octena kiselina, a u novije vrijeme sokovi citrusnog voća. Marinadama se dodaju raznovrsni začini koji joj daju karakterističan okus i miris. Proizvodi dobiveni mariniranjem nazivaju se marinade. Postoji nekoliko načina mariniranja ribe, a obuhvaćaju tradicionalne tehnologije kojima se proizvode hladne (bez termičke obrade) i vruće (kuhane ili pečene) marinade i moderne tehnologije. Svjetski trendovi promoviraju konzumaciju sirove i blago procesirane hrane, stoga moderne tehnologije mariniranja uključuju hladne marinade koje se provode upotrebom sokova citrusnog voća. Takvim blagim procesima bez termičke obrade važno je posebnu pažnju pripisati opasnostima koje sirovi proizvodi predstavljaju za potrošače.Marinating is one of the oldest chemical preservation method used to achieve mildly acid products with gentle texture and of limited shelf life. In the marination process ingredients such as salt and acetic acid, and recently juices of citrus fruit are used to for preservation of the product. Products obtained by marinating are called marinades. The aroma and flavour, and preservation of the marinades may be enhanced by addition of various spices of additives. There are several ways to marinate fish, including traditional technologies that produce cold (without thermal processing) and hot (cooked or fried) marinades and modern technology. World trends promote the consumption of raw and mildly processed foods, so modern marinating technology includes cold marinades produced with citrus fruit juices. Processing fish without thermal treatment increases possible risks for consumers, thus hazard analysis and control of raw ready-to-eat products is necessary to ensure safety of the product
The impact of climate on geographical distribution and organization
No full textU ovoj disertaciji su predstavljeni glavni utjecaji klime na geografsku raspodjelu i izgled organizama diljem svijeta. Klima je prosječno stanje atmosfere nad određenim mjestom u određenom razdoblju uzimajući u obzir prosječna i ekstremna odstupanja. Klima se određuje na temelju sljedećih klimatskih elemenata: radijacije, temperature zraka, tlaka zraka, smjera i brzine vjetra, vlažnosti zraka insolacije, naoblake, padalina i snježnog pokrivača. Sve navedeno ima izniman utjecaj na geografsku raspodjelu ali i izgled organizama. Utjecaj klime na organizme opisuje sekroz tri klimatska pravila. Allenovo pravilo je pravilo prema kojemu su tjelesni nastavci toplokrvnih organizama relativno manji kod jedinki vrste koje naseljavaju hladnija podneblja, nego kod jedinki iste vrste koje naseljavaju toplija podneblja. Glogerovo je pravilo kojim se izražava paralelizam između različitih klimatskih uvjeta (geografskih širina) i promjena u pigmentaciji životinja; npr. polazeći od ekvatora prema polovima istovrsne su životinje postupno sve svjetlije. Bergmannovo pravilo je pravilo koje govori kako suhomoiotermi hladnijih područja veći od homoioterma toplijih područja, jer se povećanjem težine životinje smanjuje površina tijela u odnosu na jedinicu težine.Dissertation presents the main climate impacts on geographical distribution and the appearance of organisms around the world. The climate is the average state of the atmospheric atmosphere over a certain place over a given period, considering the average and extreme deviations. Climate is determined based on the following climatic elements: radiation, air temperature, air pressure, direction and wind velocity, air humidity, clouds, rainfall and snow cover. All of this has an enormous impact on geographical distribution and appearance of organisms. The impact of climate on the organism is described by three climatic rules. The Allen rule is the rule that body surges of warm-blooded organisms are relatively smaller in the species that inhabit the colder climate than in the same onest hat inhabit the warmer climates. Gloger's rule expresses parallelism between different climatic conditions (geographic latitudes) and changes in animal pigmentation; e.g. starting from the equator to the poles of the same animals are gradually becoming brighter. Bergmann's rule is the rule that homoiotherms of colder areas are greater than the homoiotherm of warmer areas because by increasing the weight of an animal, the body surface is reduced relative to the weight unit
MATEMATIKA KAO PREDMET INTERESA BIOLOŠKE OCEANOGRAFIJE
No full textU ovom se radu obradila matematika iz perspektive biološke oceanografije. Matematika u kontekstu biološke oceanografije zanimljiva je tema jer upravlja cijelim nizom procesa. Rad kroz proučavanje različitih aspekata cijele problematike predstavlja ključne rezultate i tako daje doprinos fondu koji čine malobrojna istraživanja. Za istraživanje su se prikupili različiti materijali od relevantnosti za temu koji su se proučili i iz kojih su se izvukli najbitniji zaključci. Oni obuhvaćaju knjige i članke koji su uglavnom strana izdanja jer je jako malo izvora o problematici matematike u kontekstu biološke oceanografije na hrvatskom jeziku. Osim nabrajanja relevantnih aspekata, rad svaki od njih pojedinačno opisuje u svrhu davanja opsežnog odgovora na istraživačko pitanje postavljeno u uvodu. Na kraju rada se daju najvažniji zaključci.This paper discusses the math in the context of biological oceanography. The math in the context of biogical oceanography because it manages the great number of processes.The paper, through the study of different aspects of the whole problem, presents the key results and in that way gives its contribution to the fund consisted of small number of the researches. For the research, different materials are collected that are relevant for this topic, that are studied to pull out the most important conclusikons. These materijals are books and articles that are usually foreign publications, because there are so little resources that concern the problems of math in the context of biological oceanography in Croatian language. Except listing the relevant aspects, the paper decribes each of them individually to give the detailed answer on the research question set in the introduction. At the end of the paper, the most importantrr conclusions are set
RNA editing and nervous system evolution in cephalopods
No full textGlavonošci podrazreda Coleoidea posjeduju najrazvijeniji živčani sustav među beskralježnjacima. Smatra se da je njegov razvoj na molekularnoj razini rezultat određenih specifičnosti pronađenih za ovu skupinu, kao što je ekspanzija protokaderina u genomu, intenzivne aktivnosti transpozona i RNA uređivanja. Uređivanje RNA, post-transkripcijski mehanizam koji omogućava nastanak različitih proteina neovisno od genetičkog koda, izrazito je zastupljeno kod ovih organizama, i pokazuje tkivnu-specifičnost: dvostruko više modifikacija je zabilježeno u živčanom nego u ne-živčanom tkivu. Deaminacija adenozina u inozin, koju katalizira enzimska obitelj adenozinskih deaminaza specifičnih za RNA (ADAR) je karakteristični tip uređivanja za ovu skupinu. Sami ADARi su također podložni uređivanju, a kod lignje je pronađena ADAR2 izoforma s dodatnom domenom koja povećava njegovu aktivnost. Intenzivno uređivanje je uočeno i na naponskim kalijevim kanalima koji u neuronima imaju ulogu u ekscitabilnosti. Također, utvrđen je utjecaj RNA uređivanja na regulaciju brzine Na+/K+ ATPaza. Suprotno slučaju kod sisavaca, RNA uređivanje se kod glavonožaca događa na kodirajućim regijama što omogućava rekodiranje transkriptoma i diversifikaciju proteoma, ali usporava brzinu konvencionalne evolucije na razini DNA.Cephaloppods in the subclass Coleoidea possess most developed nervous system among the invertebrates. At the molecular level, it is considered that its evolution is associated with several features: expansion of the protocadherin gene family in the genome, high transposon activity and RNA editing. RNA editing, a post-transcriptional mechanism that allows the formation of different proteins independent of the genetic code, is highly represented in these organisms and exhibits tissue-specificity: twice as much modifications were observed in the nervous than in the non-nervous tissue. Deamination of adenosine to inosine, catalysed by the ADAR-specific adenosine deaminase family, is a typical type of editing for this group. ADARs themselves are also susceptible to editing, and in the squid an ADAR2 isoform was found harbouring an extra domain which increases its activity. Intensive editing was also observed for voltage gated potassium channels that in neurons play a role in excitability. Also, RNA editing affects the speed of Na + / K + ATPase transporters. Contrary to mammalian case, RNA editing in cephalopods is characteristic for the coding regions, which allows recoding of transcriptome and proteome diversification, but slows the speed of conventional DNA evolution
Influence of pH and temperature on the domoic acid content in mussels Mytilus galloprovincialis
Get PDFDomoična kiselina (DK) je neurotoksin koji je polaran i topljiv u vodi, a uzročnik je amnezijskog trovanja školjkašima (engl. Amnesic Shellfish Poisoning - ASP). Kod ljudi se trovanje domoičnom kiselinom očituje gastrointestinalnim i neurološkim simptomima. U ovom radu koristila se metoda tekućinske kromatografije i masene spektrometrije (LC-MS/MS) za kvantitativno i kvalitativno određivanje domoične kiseline u mekom tkivu dagnje Mytilus galloprovincialis. Istraživan je utjecaj pH i temperature na stabilnost domoične kiseline u metanolskim ekstraktima. Otopina metanola se koristila za ekstrakciju domoične kiseline iz tkiva organizma. Rezultati pokazuju da temperatura ne utječe značajno na stabilnost domoične kiseline, dok pH vrijednost utječe pri niskim vrijednostima.Domoic acid (DK) is a heterocyclic and water soluble neurotoxin that is responsible for Amnesic Shellfish Poisoning (ASP). The poisoning is characterized by gastrointestinal and central nervous system (CNS) clinical symptoms. In this research, the tandem method of liquid chromatography and mass spectrometry (LC-MS/MS) was used for the quantitative and qualitative determination of domoic acid in soft tissue of mussel Mytilus galloprovincialis. The influence of pH and temperature on the stability of domoic acid in methanol extracts was investigated. A methanol solution was used to extract the domoic acid from the shellfish tissue. The results show that the temperature does not significantly affect the stability of the domoic acid. Nonetheless, only low Ph values do affect its stability
Age estimation of megrims in the eastern Adriatic based on the otolith morphology and morphometry
No full textU ovom radu istražena je procjena starosti patarača Lepidorhombus boscii i Lepidorhombus whiffiagonis u istočnom Jadranu na temelju morfologije i morfometrije otolita. Istražene su 162 jedinke L. boscii i 45 jedinki L. whiffiagonis. Dužinski raspon za L. boscii iznosio je od 15 do 27,4 cm (19,99 ± 3,07). Dužinski raspon za L. whiffiagonis iznosio je od 12,9 do 29,3 cm (20,13 ± 4,06). Vrijednost alometrijskog koeficijenta za L. boscii iznosi 3,2961, dok za L. whiffiagonis iznosi 3,1311. Oba koeficijenta pokazuju pozitivan alometrijski rast. Analiza starosti vršena je uz pomoć otolita. Najviše jedinki L. whiffiagonis pripada starosnoj grupi od dvije, a najmanje starosnoj grupi od jedne godine, dok kod L. boscii najviše jedinki pripada starosnoj grupi od četiri, a najmanje starosnoj grupi od šest godina. Parametri rasta dobiveni Von Bertalanffyjevom jednadžbom za L. whiffiagonis su L∞ = 46,26; k = -0,116; t0 = 2,59, a za L. boscii L∞ = 30,77; k = -0,184; t0 = 2,50. Odnos starosti L. boscii s morfometrijskim mjerama otolita pokazao se najboljim u slučaju dužine lijevog otolita (R2 = 0,4999), dok je za L. whiffiagonis najbolja korelacija utvrđena između dužine desnog otolita i starosti (R2 = 0,5946). Razlike u oblicima lijevih i desnih otolita dviju vrsta patarača ispitane su analizom diskriminante, gdje je ustanovljeno da prva os diskriminacije objašnjava 66,6% razlike među grupama, a druga 28,5%. Na temelju rezultata analize diskriminante izvršena je klasifikacija otolita na temelju oblika, ustanovljeno je da se u 79,5% slučajeva otolit može točno svrstati u pripadajuću grupu samo na temelju oblika.This thesis presents the results of age estimation of Lepidorhombus boscii and Lepidorhombus whiffiagonis in the eastern Adriatic Sea, based on the otoith morphology and morphometry. Research was done on 162 specimens of L. boscii and 45 specimens of L. whiffiagonis. Length range for L. boscii was from 15 to 27.4 cm (19.99 ± 3.07) and for L. whiffiagonis from 12.9 to 29.3 cm (20.13 ± 4.06). Allometry coefficients for L. boscii and L. whiffiagonis were 3.2961 and 3.1311, respectively. Both coefficients showed positive allometric growth. Age analysis was performed using the otoliths. The most of the L. whiffiagonis specimens were two years old and the fewest were one year old; the most of the L. boscii specimens were four years old and the fewest were six years old. The growth parametres provided by the Von Bertalanffy's equation for L. whiffiagonis were L∞ = 46.26; k = -0.116; t0 = 2.59, and for L. boscii L∞ = 30.77; k = -0.184; t0 = 2.50. Relationship of L. boscii age with otolith morphometric measurements proved to be best for the left otolith length (R2 = 0.4999), while for L. whiffiagonis best correlation was found between age and the right otolith length (R2 = 0.5946). Differences in the shape of the left and right otoliths of both species were examined by the discriminant analysis, which showed that first discriminant axis explains 66.6% of difference between the groups, and the second 28.5%. Otolith classification done based on discriminant analysis results established that in 79.5% cases the otolith can be correctly classified based on its shape alone
Fish survival after escapement from the fishing gears
Get PDFU ovom radu analizirani su glavni čimbenici koji uzrokuju stres, ozljede i smrtnost riba nakon bijega iz ribolovnih alata, a ponajviše iz povlačne mreže koće. Glavni obrađeni čimbenici su: utjecaj veličine i oblika mrežnih oka, veličina ribe, iscrpljujuće plivanje, vremenski uvjeti na moru, temperatura mora, trajanja potega i posljedice ozljeda kože. Objašnjeni su i čimbenici koji uzrokuju smrtnost ribe ulovljene koćom nakon odbacivanja s palube, poput prisutnosti plivaćeg mjehura, vremena izloženosti na palubi, temperature mora i zraka te trajanja potega i količine ulova. Iako se rad većim dijelom bavi povlačnom mrežom koćom, obrađena je i smrtnost nakon bijega iz zaglavljujućih mreža, vrša, mreža plivarica te s udičarskih alata. Na samom kraju rada opisani su standarni postupci istraživanja smrtnosti odnosno preživljavanje riba nakon bijega iz koće, gdje je neophodno sakupiti 'pobjegle' jedinke, transportirati ih do kaveza za promatranje te kroz određeni period promatrati njihovu smrtnost.In this paper the main factors that cause stress, injury and mortality of the fish after escaping from the fishing gears, mainly trawl nets, have been analysed. The main covered factors are: mesh size and shape, fish size, swimming exhaustion, weather conditions at sea, sea temperature, duration of the tow and the consequences of skin injuries. Factors that cause death of discarded fish (caught by the trawl and discarded from the deck of the vessel) have been explained, such as the presence of a swim bladder, exposure time on the deck, sea and air temperature, duration of the tow and total catch amount. Although the main focus of the paper is trawl induced mortality, the mortality related to other fishing gears (gillnets, pots, purse sines, hook and line gears) has also been described. In the last chapter, the standard research methods used to estimate survival of fish after the escape from the trawl codend are described, with basic steps of collecting 'escaped' individuals, transporting them to the observation cages and observing their mortality for a certain period of time
Biological features of John Dory (Zeus faber) as a cosmopolitan fish species
No full textU radu su opisane najvažnije biološke značajke kovača, kao kozmopolitske vrste riba, na temelju dosadašnjih istraživanja. Kovač je gospodarski značajna vrsta, no njegove biološke osobitosti onemogućuju mu brzu obnovu populacija. Dužina prve spolne zrelosti nalazi se u rasponu od 25 – 35 cm što predstavlja najveći problem u stvaranju novih generacija. Ova veličina predstavlja prekretnicu u promjeni prehrane, s manje ribe i rakova na gotovo potpunu prehranu većom ribom. U većini istraživanja uočena je brojčana dominacija ženki, 1,6:1 što je pozitivna činjenica koja bi s adekvatnim mjerama mogla pomoći obnavljanju populacija ove vrste.On the basis of the recent research this paper presents the most important features of John Dory, as one of the cosmopolitan fish species. John Dory is from a commercial point of view an important species, but its biological features don’t allow fast growth of its population. As each fish needs to reach a length of 25 – 35 centimetres before it can engage in its first reproductive cycle, the production of new generations is therefore slow. This size represents a turning point in nutrition change, with less fish and crustaceans to almost complete nutrition with larger fish. It’s interesting to note that majority of research records a greater number of females than males, with a 1.6:1 ratio. This is a positive fact which could, through adequate measures, help restore the population of this species