Adjustments of fishes to specific conditions in extreme habitats

Ribe su najbrojniji kralješnjaci. Nalazimo ih u dubokom moru gdje nema svjetla i gdje je enorman tlak. U polarnim vodama gdje je temperatura vode ispod nula °C. Naselile su i pustinjske izvore gdje su potpuno izolirane i lokve u pustinjama u kojima ima vode samo nekoliko mjeseci tokom godine. Žive čak i u podzemnim vodama gdje nemaju gotovo nikakvog kontakta s vanjskim svijetom. Budući da su se ribe pojavile prije 500 milijuna godina, uspjele su se evolucijski prilagoditi i na takva, najekstremnija, staništa. U radu su izložene prilagodbe na uvjete u takvim staništima.Fishes are the most abundant vertebrates. We find them in deep sea where there is no light and the pressure is enormous. In polar waters where water temperature drops below zero °C. They inhabitated desert springs where they are completely isolated and desert puddles which contain water only a few months throughout the year. They even live in underground water systems where there is practically no contact with the outside world. Considering that fishes first appeared 500 million years ago, they managed to adjust through their evolution to even the most extreme habitats. In this work is a list of adjustments to conditions in that kind of habitats

Adjustments of fishes to specific conditions in extreme habitats

Ribe su najbrojniji kralješnjaci. Nalazimo ih u dubokom moru gdje nema svjetla i gdje je enorman tlak. U polarnim vodama gdje je temperatura vode ispod nula °C. Naselile su i pustinjske izvore gdje su potpuno izolirane i lokve u pustinjama u kojima ima vode samo nekoliko mjeseci tokom godine. Žive čak i u podzemnim vodama gdje nemaju gotovo nikakvog kontakta s vanjskim svijetom. Budući da su se ribe pojavile prije 500 milijuna godina, uspjele su se evolucijski prilagoditi i na takva, najekstremnija, staništa. U radu su izložene prilagodbe na uvjete u takvim staništima.Fishes are the most abundant vertebrates. We find them in deep sea where there is no light and the pressure is enormous. In polar waters where water temperature drops below zero °C. They inhabitated desert springs where they are completely isolated and desert puddles which contain water only a few months throughout the year. They even live in underground water systems where there is practically no contact with the outside world. Considering that fishes first appeared 500 million years ago, they managed to adjust through their evolution to even the most extreme habitats. In this work is a list of adjustments to conditions in that kind of habitats

Adjustments of fishes to specific conditions in extreme habitats

Ribe su najbrojniji kralješnjaci. Nalazimo ih u dubokom moru gdje nema svjetla i gdje je enorman tlak. U polarnim vodama gdje je temperatura vode ispod nula °C. Naselile su i pustinjske izvore gdje su potpuno izolirane i lokve u pustinjama u kojima ima vode samo nekoliko mjeseci tokom godine. Žive čak i u podzemnim vodama gdje nemaju gotovo nikakvog kontakta s vanjskim svijetom. Budući da su se ribe pojavile prije 500 milijuna godina, uspjele su se evolucijski prilagoditi i na takva, najekstremnija, staništa. U radu su izložene prilagodbe na uvjete u takvim staništima.Fishes are the most abundant vertebrates. We find them in deep sea where there is no light and the pressure is enormous. In polar waters where water temperature drops below zero °C. They inhabitated desert springs where they are completely isolated and desert puddles which contain water only a few months throughout the year. They even live in underground water systems where there is practically no contact with the outside world. Considering that fishes first appeared 500 million years ago, they managed to adjust through their evolution to even the most extreme habitats. In this work is a list of adjustments to conditions in that kind of habitats

FLUCTUATING ASYMMETRY IN MORPHOLOGICAL CHARACTERS OF THE INVASIVE ROUND GOBY Neogobius melanostomus POPULATIONS FROM DIFFERENT HABITATS OF THE SAVA RIVER BASIN, CROATIA

Glavočić okrugljak, Neogobius melanostomus, jedan je od tri invazivna ponto-kaspijska glavoča pronađena u slivu rijeke Save u Hrvatskoj. Ima negativan učinak na izvorne ekosustave, a veći broj individua pronalazi se na jače zagađenim mjestima. Cilj ovog istraživanja je utvrditi fluktuirajuću asimetriju morfometrijskih značajki tijela te širine i dužine otolita. Na dva mjesta uzorkovanja u glavnom toku rijeke Save (Babina Greda, Slavonski Brod) i izmijenjenom staništu (kanal Sava-Odra) prikupljeno je i analizirano 30 jedinki N. melanostomus. Kvadratni koeficijent varijacije asimetrije korišten je za analizu potencijalnih razlika između populacija. Identificirane su varijacije u vrijednostima asimetrije analiziranih morfometrijskih značajki te širini i dužini otolita između mjesta uzorkovanja. Najveća fluktuirajuća asimetrija uočena je kod jedinki na mjestu uzorkovanja Babina Greda, što može biti posljedica visokog pritiska onečišćenja okoliša. Rezultati studije pokazuju da se metoda fluktuirajuće asimetrije može koristiti na invazivnim vrstama riba kao jednostavan pristup u identifikaciji kvalitete okoliša staništa.Round goby Neogobius melanostomus is one of the three invasive Ponto-Caspian gobies found in the Sava River basin in Croatia. It has a negative effect on the native ecosystems and is more abundant in highly polluted areas. The objective of this study was to determine the fluctuating asymmetry of four morphometric characters, as well as otolith width and length. Thirty individuals of N. melanostomus were collected and analysed at two sampling sites in the main course of the Sava (Babina Greda, Slavonski Brod) and in a modified habitat (Sava-Odra canal). The squared coefficient of asymmetry variation was used to analyse potential differences between populations. We identified variations in the asymmetry values of the analysed characters, as well as otolith width and length between sampling sites. The highest fluctuating asymmetry was observed in individuals at the Babina Greda sampling site, which could be due to high environmental stress. The results of the study show that the study of fluctuating asymmetry can be used on invasive fish species as a simple approach to identifying habitat quality

Pestizide in Oberflächengewässern

Pesticidi omogućavaju velike prinose u poljoprivredi koji su potrebni za zadovoljavanje potreba moderne civilizacije. To ih čini neophodnima usprkos brojnim negativnim utjecajima na okoliš. U vodenim staništima štetni su za organizme, izravno i neizravno, a vrijeme oporavka zajednice ovisi o mjestu i vremenu onečišćenja, kao i o koncentraciji pesticida. Najučinkovitija mjera ublažavanja štetnih učinaka pesticida u vodenim staništima je spriječiti da pesticidi dospiju do vodenih ekosustava, što se postiže odgovornim korištenjem i zaštitnim mjerama, poput vegetacijskih tampon zona i kanala s vegetacijom koji zadržavaju štetne tvari i usporavaju njihovo deponiranje u otvorenim vodama.Pesticides enable high agricultural yields needed to fulfil the demands of modern civilisation. This makes pesticides necessary despite their numerous negative impacts on the environment. Pesticides may cause direct or indirect damage to any group of organisms in aquatic habitats. The length of time needed for the rehabilitation of a community depends on the location and time of pollution as well as on the concentration of pesticides. The most efficient mitigation measure against harmful impacts of pesticides on aquatic habitats is the prevention of their entry into aquatic ecosystems, which can be achieved by their responsible use and protection measures, such as vegetation buffer zones and canals overgrown with vegetation that retain harmful substances and slow down their disposal in open inland waters.Der Pestizideinsatz ermöglicht hohe Erträge in der Landwirtschaft, die für die Befriedigung von Bedürfnissen der modernen Zivilisation erforderlich sind. So sind Pestizide unentbehrlich trotz ihrer zahlreichen negativen Auswirkungen auf die Umwelt. In aquatischen Lebensräumen schaden sie allen Organismen, direkt oder indirekt, und die Erholungszeit für eine Artgemeinschaft hängt von der Stelle und der Zeit der Verschmutzung sowie der Pestizidkonzentration ab. Die wirksamste Maßnahme zur Abschwächung der schädlichen Auswirkungen von Pestiziden in aquatischen Lebensräumen ist es zu verhindern, dass Pestizide in aquatische Ökosysteme gelangen, was durch verantwortungsvollen Umgang und mit Schutzmaßnahmen erzielt wird, z.B. mit Vegetationspufferzonen und Kanälen mit Vegetation, die Schadstoffe zurückhalten und ihre Deponierung in Oberflächengewässern verlangsamen

VARIATIONS IN OTOLITH AND SCALE SHAPE OF THE INVASIVE ROUND GOBY Neogobius melanostomus POPULATIONS FROM DIFFERENT HABITATS OF THE SAVA RIVER BASIN, CROATIA

Glavočić okrugljak Neogobius melanostomus jedna je od tri invazivne vrste ponto-kaspijskih glavoča prisutnih u hrvatskom dijelu slijeva rijeke Save. Ima negativan učinak na zavičajne ekosustave zahvaljujući visokom invazivnom potencijalu koji omogućuje njegovo brzo širenje uzvodno u kopnenim vodotocima. Cilj istraživanja bio je utvrditi moguće razlike u obliku otolita i ljuski između ustaljenih i frontalnih populacija invazivnog N. melanostomus u dva različita staništa. Uzorkovane su dvije lokacije u glavnom toku rijeke Save (Babina Greda, Slavonski Brod) i jedna lokacija u izmijenjenom staništu (kanal Sava Odra) pri čemu je prikupljeno i analizirano 20 jedinki N. melanostomus. Za analizu oblika otolita i ljuski primijenjena je geometrijska morfometrija, Prokrustova analiza varijance, kanonička analiza varijacije i diskriminantna funkcijska analiza. Utvrđena je statistički značajna razlika u obliku otolita i ljuski između naseljene (Babina Greda) i frontalne (Slavonski Brod) populacije u glavnom toku rijeke Save. Glavne razlike bile su širi prednji dio ljuski i izraženije otvoreno udubljenje na otolitu populacije naseljene na lokaciji Babina Greda. Naseljena populacija u kanalu Sava-Odra značajno se razlikovala od populacije Babine Grede, ali ne i od populacije Slavonskog Broda, što sugerira na mogućnost da se uzvodna migracija sastoji od jedinki specifičnog fenotipa i genotipa. Otoliti općenito izražavaju veću varijabilnost oblika nego ljuske i stoga mogu biti korisniji za utvrđivanje razlika između bliskih populacija. Rezultati istraživanja sugeriraju da se oblik otolita i ljusaka može primijeniti za razlikovanje bliskih N. melanostomus populacija iz različitog staništa, ali zbog malog broja uzoraka se predlaže opsežnija studija.Round goby Neogobius melanostomus is one of the three invasive Ponto-Caspian gobies found in the Sava River basin in Croatia. It has a negative effect on the native ecosystems due to its high invasive potential that enables its rapid spread upstream in inland watercourses. The objective of this study was to determine the differences in sagittal otolith and scale shape of the frontal and established populations of N. melanostomus in two different habitat types. At two sampling sites in the main course of the Sava (Babina Greda, Slavonski Brod) and in a modified habitat (Sava-Odra canal), 20 individuals of N. melanostomus were collected and analysed. The geometric morphometric method was used together with Procrustes analysis of variance, canonical variate analysis and discriminant function analysis to analyse the otolith and scale shape. Significant differences in both otolith and scale shapes were found between settled (Babina Greda) and frontal (Slavonski Brod) populations from the main course of the Sava River. The main differences were the wider anterior part of the scales and a more pronounced open indentation on the otolith of the Babina Greda population. The settled population in the Sava-Odra canal was significantly different in otolith shape from the Babina Greda population but not from the Slavonski Brod population, suggesting that the upstream migration consisted of individuals with specific phenotype and genotype. Otoliths generally expressed greater shape variability than scales and thus may be more useful for differentiating between closely related populations on a finer scale. The results of this study suggest that the shape of otoliths and scales can be used to distinguish between closely related populations of N. melanostomus from different habitats but more comprehensive studies are needed due to the small number of samples

FLUCTUATING ASYMMETRY IN MORPHOLOGICAL CHARACTERS OF THE INVASIVE ROUND GOBY Neogobius melanostomus POPULATIONS FROM DIFFERENT HABITATS OF THE SAVA RIVER BASIN, CROATIA

Glavočić okrugljak, Neogobius melanostomus, jedan je od tri invazivna ponto-kaspijska glavoča pronađena u slivu rijeke Save u Hrvatskoj. Ima negativan učinak na izvorne ekosustave, a veći broj individua pronalazi se na jače zagađenim mjestima. Cilj ovog istraživanja je utvrditi fluktuirajuću asimetriju morfometrijskih značajki tijela te širine i dužine otolita. Na dva mjesta uzorkovanja u glavnom toku rijeke Save (Babina Greda, Slavonski Brod) i izmijenjenom staništu (kanal Sava-Odra) prikupljeno je i analizirano 30 jedinki N. melanostomus. Kvadratni koeficijent varijacije asimetrije korišten je za analizu potencijalnih razlika između populacija. Identificirane su varijacije u vrijednostima asimetrije analiziranih morfometrijskih značajki te širini i dužini otolita između mjesta uzorkovanja. Najveća fluktuirajuća asimetrija uočena je kod jedinki na mjestu uzorkovanja Babina Greda, što može biti posljedica visokog pritiska onečišćenja okoliša. Rezultati studije pokazuju da se metoda fluktuirajuće asimetrije može koristiti na invazivnim vrstama riba kao jednostavan pristup u identifikaciji kvalitete okoliša staništa.Round goby Neogobius melanostomus is one of the three invasive Ponto-Caspian gobies found in the Sava River basin in Croatia. It has a negative effect on the native ecosystems and is more abundant in highly polluted areas. The objective of this study was to determine the fluctuating asymmetry of four morphometric characters, as well as otolith width and length. Thirty individuals of N. melanostomus were collected and analysed at two sampling sites in the main course of the Sava (Babina Greda, Slavonski Brod) and in a modified habitat (Sava-Odra canal). The squared coefficient of asymmetry variation was used to analyse potential differences between populations. We identified variations in the asymmetry values of the analysed characters, as well as otolith width and length between sampling sites. The highest fluctuating asymmetry was observed in individuals at the Babina Greda sampling site, which could be due to high environmental stress. The results of the study show that the study of fluctuating asymmetry can be used on invasive fish species as a simple approach to identifying habitat quality

Pestizide in Oberflächengewässern

Pesticidi omogućavaju velike prinose u poljoprivredi koji su potrebni za zadovoljavanje potreba moderne civilizacije. To ih čini neophodnima usprkos brojnim negativnim utjecajima na okoliš. U vodenim staništima štetni su za organizme, izravno i neizravno, a vrijeme oporavka zajednice ovisi o mjestu i vremenu onečišćenja, kao i o koncentraciji pesticida. Najučinkovitija mjera ublažavanja štetnih učinaka pesticida u vodenim staništima je spriječiti da pesticidi dospiju do vodenih ekosustava, što se postiže odgovornim korištenjem i zaštitnim mjerama, poput vegetacijskih tampon zona i kanala s vegetacijom koji zadržavaju štetne tvari i usporavaju njihovo deponiranje u otvorenim vodama.Pesticides enable high agricultural yields needed to fulfil the demands of modern civilisation. This makes pesticides necessary despite their numerous negative impacts on the environment. Pesticides may cause direct or indirect damage to any group of organisms in aquatic habitats. The length of time needed for the rehabilitation of a community depends on the location and time of pollution as well as on the concentration of pesticides. The most efficient mitigation measure against harmful impacts of pesticides on aquatic habitats is the prevention of their entry into aquatic ecosystems, which can be achieved by their responsible use and protection measures, such as vegetation buffer zones and canals overgrown with vegetation that retain harmful substances and slow down their disposal in open inland waters.Der Pestizideinsatz ermöglicht hohe Erträge in der Landwirtschaft, die für die Befriedigung von Bedürfnissen der modernen Zivilisation erforderlich sind. So sind Pestizide unentbehrlich trotz ihrer zahlreichen negativen Auswirkungen auf die Umwelt. In aquatischen Lebensräumen schaden sie allen Organismen, direkt oder indirekt, und die Erholungszeit für eine Artgemeinschaft hängt von der Stelle und der Zeit der Verschmutzung sowie der Pestizidkonzentration ab. Die wirksamste Maßnahme zur Abschwächung der schädlichen Auswirkungen von Pestiziden in aquatischen Lebensräumen ist es zu verhindern, dass Pestizide in aquatische Ökosysteme gelangen, was durch verantwortungsvollen Umgang und mit Schutzmaßnahmen erzielt wird, z.B. mit Vegetationspufferzonen und Kanälen mit Vegetation, die Schadstoffe zurückhalten und ihre Deponierung in Oberflächengewässern verlangsamen

Introduced species community over-dominates endemic ichthyofauna of High Lika Plateau (Central Croatia) over a 100 year period

108 years after Trgovčić (1908) authors made a revised list of fish species found in rivers and streams of the Lika region. Throughout the 8 years of investigation a total of 31 species of freshwater fish were recorded, of which only eight are indigenous for this area, for two species the origin is not known, and the remaining 21 species are introduced by anthropogenic activity over the last 100 years. This represents the over-domination of introduced species by the astonishing 300%. All of this increase in numbers causes significant increase in biomass and changes the naturally oligotrophic ecosystem, which might lead to rapid eutrophication and increase of water temperature. Furthermore, induced changes in the system make the habitat more suitable for introduced cyprinid fish, which again causes the increase of biomass production. Endemic fish species are retreating into upper parts of small tributaries and underground cave systems. The present research indicates species Delminichthys jadovensis, D. krbavensis, Telestes fontinalis and T. croaticus as real stygophiles, which makes them unique on the European continent

Morphological traits and condition of brown trout Salmo trutta from Žumberak and Samobor mountain streams

Populacije potočne pastrve i njihova morfološka različitost u potocima Samoborsko-žumberačkog gorja još nije istraživana. Stoga je cilj ovog rada bio utvrditi kondiciju, dužinsko masene odnose, morfometrijske i merističke značajke između pet populacija potočne pastrve. Analizirano je ukupno 70 primjeraka potočne pastrve. Najniži Fultonov kondicijski faktor zabilježen je na potoku Kupčina, a najviši na potoku Slapnica. Negativan alometrijski rast jedinki zabilježen je jedino na potoku Gradna. Utvrđene su značajne statističke razlike za duljinu glave, širinu i visinu usta, visinu leđne i prsne peraje, broju mekih žbica u leđnoj peraji i broju piloričkih nastavaka između lokacija. Najveća sličnost jedinki potočne pastrve na temelju morfometrijskih i merističkih značajki uočena je između populacija potoka Slapnice i Rudarske Gradne. Identificirana statistički značajna morfometrijska svojstva ukazuju na genetsku varijabilnost između analiziranih uzoraka i mogućnost da je vršeno poribljavanje s linijama pastrva iz uzgoja, osobito na potocima Slapnica i Rudarska Gradna.Daljnja istraživanja trebaju biti usmjerena na molekularne analize kako bi se utvrdila prisutnost Atlantskih linija potočne pastrve (unesenih za potrebe uzgoja) i njihove potencijalne introgresije gena u domaću Dunavsku pastrvu, kako bi se predložile odgovarajuće mjere zaštite.Until now brown trout populations, and their morphological dinstinction in Samobor-Žumberak mountain streams, have not been investigated. The aim of this research was to determine condition factor, length-weight relationship, morphometric and meristic differences between five brown trout populations. In total, 70 specimens of brown trout were analysed. The lowest Fulton condition factor was observed at Kupčina and the highest at the Slapnica stream. Only specimens from Gradna stream demonstrated negative allometric growth. Significant statistical differences between the investigated sites have been identified for head length, mouth width and height, dorsal and pectoral fin height, the number of soft rays in the dorsal fin, and the number of pyloric caeca. The highest similarity between brown trout specimens, based on morphometric and meristic traits, has been observed between the Slapnica and Rudarska Gradna streams. Identified statistically significant morphometric traits suggest genetic variability between analysed specimens and the potential efficacy of stocking with feral brown trout, particularly at the Slapnica and Rudarska Gradna streams. Further research should be focused on the use of molecular analyses to determine the presence of Atlantic lineages (feral) of brown trout, and gene introgression to native wild strains in order to suggest potentially effective conservation measures