Culture of Seriola dumerili in a marine ecosystem: Insights from genetic and morphometric fish traits and implications of escape events

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Prisutnost alohtone kamenice Crassostrea gigas u Jadranskom moru

The Pacific oyster, Crassostrea gigas, was introduced into the Europe in the late 1960s for aquaculture purposes and has since spread extensively in Mediterranean waters. For the first time, screening of the four ecologically most suitable bays along the Eastern Adriatic coast was conducted to detect the possible presence of non-native oysters. Sequencing analysis of a fragment of mitochondrial 16S rRNA was examined to demonstrate the presence of the exotic species C. gigas in the natural environments of the northern and central coastal areas of the eastern Adriatic. The likely routes of invasion are discussed and the importance of monitoring the distribution of feral C. gigas populations emphasized, with a focus on the potential direct and indirect effects on the native European flat oyster, Ostrea edulis.Japanska ili pacifička kamenica, Crassostrea gigas, uvedena je u Europu kasnih 1960-ih za potrebe akvakulture i od tada se intenzivno proširila po Mediteranu. Po prvi put je izvršen pregled četiriju ekološki najprikladnijih zaljeva istočne obale Jadrana kako bi se utvrdila prisutnost alohtone kamenice. Analiza djelomičnog fragmenta mitohondrijske 16S rRNA je korištena kako bi se molekularno identificirala egzotična vrsta C. gigas u prirodnim staništima sjevernih i središnjih obalnih područja istočnog Jadrana. Mogući invazijski putevi su raspravljani kao i važnost praćenja distribucije populacija C. gigas, s naglaskom na potencijalne izravne i neizravne učinke na autohtonu europsku plosnatu kamenicu Ostrea edulis koja obitava u Jadranskom moru

Prisutnost alohtone kamenice Crassostrea gigas u Jadranskom moru

The Pacific oyster, Crassostrea gigas, was introduced into the Europe in the late 1960s for aquaculture purposes and has since spread extensively in Mediterranean waters. For the first time, screening of the four ecologically most suitable bays along the Eastern Adriatic coast was conducted to detect the possible presence of non-native oysters. Sequencing analysis of a fragment of mitochondrial 16S rRNA was examined to demonstrate the presence of the exotic species C. gigas in the natural environments of the northern and central coastal areas of the eastern Adriatic. The likely routes of invasion are discussed and the importance of monitoring the distribution of feral C. gigas populations emphasized, with a focus on the potential direct and indirect effects on the native European flat oyster, Ostrea edulis.Japanska ili pacifička kamenica, Crassostrea gigas, uvedena je u Europu kasnih 1960-ih za potrebe akvakulture i od tada se intenzivno proširila po Mediteranu. Po prvi put je izvršen pregled četiriju ekološki najprikladnijih zaljeva istočne obale Jadrana kako bi se utvrdila prisutnost alohtone kamenice. Analiza djelomičnog fragmenta mitohondrijske 16S rRNA je korištena kako bi se molekularno identificirala egzotična vrsta C. gigas u prirodnim staništima sjevernih i središnjih obalnih područja istočnog Jadrana. Mogući invazijski putevi su raspravljani kao i važnost praćenja distribucije populacija C. gigas, s naglaskom na potencijalne izravne i neizravne učinke na autohtonu europsku plosnatu kamenicu Ostrea edulis koja obitava u Jadranskom moru

Phenotypic traits of gilthead seabream Sparus aurata (Linnaeus, 1758) in wild and human-mediated environments of the eastern Adriatic Sea

Ribe, kao živi organizmi, izrazito su prilagodljive prirodnim i antropogeno uvjetovanim okolišima gdje svojstvo fenotipske plastičnosti omogućava poveznicu starih i novih sredina putem morfoloških, fizioloških prilagodbi ponašanja. Posljednjih godina zamijećeno je povećanje ulova divlje komarče na području istočnog Jadranskog mora, gdje riblji zbjegovi i priljev jedinki iz kavezno povezanih okoliša uzgajališta tuna doprinose povećanju brojnosti populacija u prirodnom staništu. Predmetnim istraživanjem vrednovane su fenotipske prilagodbe kod komarče u okolišu pod utjecajem kaveznog uzgoja tuna te fenotipska obilježja divljih i uzgojnih populacija s ciljem razvoja brzog i učinkovitog alata za raspoznavanje zbjegova u lovini. Primjenom metoda geometrijske morfometrije kvantificirana su morfološka obilježja tijela i otolita, dok je fiziološki odgovor promatran kroz trofički status i spolna obilježja protandričnih populacija. Cjelogodišnja prostorna i vremenska zastupljenost komarči oko uzgajališta tuna upućuje na važnu ulogu jadranskih uzgajališta tuna kao pogodnih staništa za divlju komarču. Taj izmijenjeni okoliš u kojem prevladava drugačija dinamika morskih struja i dostupnost plijena uvjetovao je specifičan odgovor kod komarče formirajući novi kavezno povezani morfotip. Manja i tuplja glava te vretenastije tijelo predstavljaju osnovna obilježja spomenutog morfotipa. U blizini kaveza tuna dokumentirana je promjena spola komarče pri nižim dužinskim veličinama u odnosu na prirodne populacije zbog značajne trofičke podrške koja osigurava bolji kondicijski i reproduktivni status. Promatrajući divlje i uzgojne komarče, primjenom metoda geometrijske morfometrije uspješno su klasificirane jedinke prema izvornom podrijetlu u iznosu od 99,6 % s obzirom na oblik tijela te više od 70 % u odnosu na oblik otolita. Zaokruženiji profil glave sa supraterminalnim pozicioniranim ustima te zdepast oblik tijela s tamnijom i bljeđom srebrnkasto-sivom obojenošću glavna su obilježja uzgojnih komarči, dok su divlje jedinke opisane s izduženijim tijelom i subterminalnim ustima na većem profilu glave. Prikupljene informacije primjenjive su u budućim biotehnološkim istraživanjima za potrebe prepoznavanja podrijetla ribe strojnim učenjem i dugoročno u upravljanju zbjegovima te u razvoju selekcijskih programa vrsta iz akvakulture.Fish, as living organisms, are highly adaptable to natural and human-mediated environments due to their morphological, physiological and behavioural adaptations through phenotypic plasticity. In recent years, a increase of gilthead seabream in fisheries landings has been documented in the eastern Adriatic Sea, with aquaculture escapes and spillover of seabream from tuna farm concession areas contributing to population increases in natural habitats. The aim of this research was to investigate the phenotypic adaptations of gilthead seabream in a tuna farm impacted environment and to evaluate the phenotypic characteristics of wild and farmed populations in order to develop a rapid and effective tool for detecting escapes in fisheries landings. Morphological characteristics of body and otolith shape were quantified by geometric morphometrics methods, while physiological responses were studied through trophic status and sexual characteristics of protandrous populations. The year-round spatial and temporal occurrence of seabream near tuna farms indicates that they play an important role as suitable habitat for wild seabream populations in the Adriatic Sea. This altered environment, characterised by different hydrodynamics and prey availability compared to natural habitats, has triggered a specific phenotypic response of seabream by forming a new morphotype associated with tuna farms. The smaller and blunt head and the more spindle-shaped body are the main characteristics of the mentioned morphotype. In the vicinity of tuna farms, the sex change of seabream has been documented at lower lengths compared to wild populations, due to the significant trophic support that ensures better condition and reproductive status. When observing wild and farmed seabream, geometric morphometrics methods successfully assigned 99.6% of individuals to their correct origin in terms of body shape and more than 70% in terms of otolith shape. A rounder head profile with a supraterminal positioned mouth and a stocky body shape with darker and paler silver-grey coloration are the main characteristics of farmed seabream, while wild individuals are described with an elongated body and a subterminal mouth on a larger head profile. The information collected in this research can be used in future biotechnological research to identify the origin of fish through machine learning and, in the long term, in the management of escapes and the development of selection programmes for aquaculture species

Phenotypic traits of gilthead seabream Sparus aurata (Linnaeus, 1758) in wild and human-mediated environments of the eastern Adriatic Sea

Ribe, kao živi organizmi, izrazito su prilagodljive prirodnim i antropogeno uvjetovanim okolišima gdje svojstvo fenotipske plastičnosti omogućava poveznicu starih i novih sredina putem morfoloških, fizioloških prilagodbi ponašanja. Posljednjih godina zamijećeno je povećanje ulova divlje komarče na području istočnog Jadranskog mora, gdje riblji zbjegovi i priljev jedinki iz kavezno povezanih okoliša uzgajališta tuna doprinose povećanju brojnosti populacija u prirodnom staništu. Predmetnim istraživanjem vrednovane su fenotipske prilagodbe kod komarče u okolišu pod utjecajem kaveznog uzgoja tuna te fenotipska obilježja divljih i uzgojnih populacija s ciljem razvoja brzog i učinkovitog alata za raspoznavanje zbjegova u lovini. Primjenom metoda geometrijske morfometrije kvantificirana su morfološka obilježja tijela i otolita, dok je fiziološki odgovor promatran kroz trofički status i spolna obilježja protandričnih populacija. Cjelogodišnja prostorna i vremenska zastupljenost komarči oko uzgajališta tuna upućuje na važnu ulogu jadranskih uzgajališta tuna kao pogodnih staništa za divlju komarču. Taj izmijenjeni okoliš u kojem prevladava drugačija dinamika morskih struja i dostupnost plijena uvjetovao je specifičan odgovor kod komarče formirajući novi kavezno povezani morfotip. Manja i tuplja glava te vretenastije tijelo predstavljaju osnovna obilježja spomenutog morfotipa. U blizini kaveza tuna dokumentirana je promjena spola komarče pri nižim dužinskim veličinama u odnosu na prirodne populacije zbog značajne trofičke podrške koja osigurava bolji kondicijski i reproduktivni status. Promatrajući divlje i uzgojne komarče, primjenom metoda geometrijske morfometrije uspješno su klasificirane jedinke prema izvornom podrijetlu u iznosu od 99,6 % s obzirom na oblik tijela te više od 70 % u odnosu na oblik otolita. Zaokruženiji profil glave sa supraterminalnim pozicioniranim ustima te zdepast oblik tijela s tamnijom i bljeđom srebrnkasto-sivom obojenošću glavna su obilježja uzgojnih komarči, dok su divlje jedinke opisane s izduženijim tijelom i subterminalnim ustima na većem profilu glave. Prikupljene informacije primjenjive su u budućim biotehnološkim istraživanjima za potrebe prepoznavanja podrijetla ribe strojnim učenjem i dugoročno u upravljanju zbjegovima te u razvoju selekcijskih programa vrsta iz akvakulture.Fish, as living organisms, are highly adaptable to natural and human-mediated environments due to their morphological, physiological and behavioural adaptations through phenotypic plasticity. In recent years, a increase of gilthead seabream in fisheries landings has been documented in the eastern Adriatic Sea, with aquaculture escapes and spillover of seabream from tuna farm concession areas contributing to population increases in natural habitats. The aim of this research was to investigate the phenotypic adaptations of gilthead seabream in a tuna farm impacted environment and to evaluate the phenotypic characteristics of wild and farmed populations in order to develop a rapid and effective tool for detecting escapes in fisheries landings. Morphological characteristics of body and otolith shape were quantified by geometric morphometrics methods, while physiological responses were studied through trophic status and sexual characteristics of protandrous populations. The year-round spatial and temporal occurrence of seabream near tuna farms indicates that they play an important role as suitable habitat for wild seabream populations in the Adriatic Sea. This altered environment, characterised by different hydrodynamics and prey availability compared to natural habitats, has triggered a specific phenotypic response of seabream by forming a new morphotype associated with tuna farms. The smaller and blunt head and the more spindle-shaped body are the main characteristics of the mentioned morphotype. In the vicinity of tuna farms, the sex change of seabream has been documented at lower lengths compared to wild populations, due to the significant trophic support that ensures better condition and reproductive status. When observing wild and farmed seabream, geometric morphometrics methods successfully assigned 99.6% of individuals to their correct origin in terms of body shape and more than 70% in terms of otolith shape. A rounder head profile with a supraterminal positioned mouth and a stocky body shape with darker and paler silver-grey coloration are the main characteristics of farmed seabream, while wild individuals are described with an elongated body and a subterminal mouth on a larger head profile. The information collected in this research can be used in future biotechnological research to identify the origin of fish through machine learning and, in the long term, in the management of escapes and the development of selection programmes for aquaculture species

Phenotypic traits of gilthead seabream Sparus aurata (Linnaeus, 1758) in wild and human-mediated environments of the eastern Adriatic Sea

Ribe, kao živi organizmi, izrazito su prilagodljive prirodnim i antropogeno uvjetovanim okolišima gdje svojstvo fenotipske plastičnosti omogućava poveznicu starih i novih sredina putem morfoloških, fizioloških prilagodbi ponašanja. Posljednjih godina zamijećeno je povećanje ulova divlje komarče na području istočnog Jadranskog mora, gdje riblji zbjegovi i priljev jedinki iz kavezno povezanih okoliša uzgajališta tuna doprinose povećanju brojnosti populacija u prirodnom staništu. Predmetnim istraživanjem vrednovane su fenotipske prilagodbe kod komarče u okolišu pod utjecajem kaveznog uzgoja tuna te fenotipska obilježja divljih i uzgojnih populacija s ciljem razvoja brzog i učinkovitog alata za raspoznavanje zbjegova u lovini. Primjenom metoda geometrijske morfometrije kvantificirana su morfološka obilježja tijela i otolita, dok je fiziološki odgovor promatran kroz trofički status i spolna obilježja protandričnih populacija. Cjelogodišnja prostorna i vremenska zastupljenost komarči oko uzgajališta tuna upućuje na važnu ulogu jadranskih uzgajališta tuna kao pogodnih staništa za divlju komarču. Taj izmijenjeni okoliš u kojem prevladava drugačija dinamika morskih struja i dostupnost plijena uvjetovao je specifičan odgovor kod komarče formirajući novi kavezno povezani morfotip. Manja i tuplja glava te vretenastije tijelo predstavljaju osnovna obilježja spomenutog morfotipa. U blizini kaveza tuna dokumentirana je promjena spola komarče pri nižim dužinskim veličinama u odnosu na prirodne populacije zbog značajne trofičke podrške koja osigurava bolji kondicijski i reproduktivni status. Promatrajući divlje i uzgojne komarče, primjenom metoda geometrijske morfometrije uspješno su klasificirane jedinke prema izvornom podrijetlu u iznosu od 99,6 % s obzirom na oblik tijela te više od 70 % u odnosu na oblik otolita. Zaokruženiji profil glave sa supraterminalnim pozicioniranim ustima te zdepast oblik tijela s tamnijom i bljeđom srebrnkasto-sivom obojenošću glavna su obilježja uzgojnih komarči, dok su divlje jedinke opisane s izduženijim tijelom i subterminalnim ustima na većem profilu glave. Prikupljene informacije primjenjive su u budućim biotehnološkim istraživanjima za potrebe prepoznavanja podrijetla ribe strojnim učenjem i dugoročno u upravljanju zbjegovima te u razvoju selekcijskih programa vrsta iz akvakulture.Fish, as living organisms, are highly adaptable to natural and human-mediated environments due to their morphological, physiological and behavioural adaptations through phenotypic plasticity. In recent years, a increase of gilthead seabream in fisheries landings has been documented in the eastern Adriatic Sea, with aquaculture escapes and spillover of seabream from tuna farm concession areas contributing to population increases in natural habitats. The aim of this research was to investigate the phenotypic adaptations of gilthead seabream in a tuna farm impacted environment and to evaluate the phenotypic characteristics of wild and farmed populations in order to develop a rapid and effective tool for detecting escapes in fisheries landings. Morphological characteristics of body and otolith shape were quantified by geometric morphometrics methods, while physiological responses were studied through trophic status and sexual characteristics of protandrous populations. The year-round spatial and temporal occurrence of seabream near tuna farms indicates that they play an important role as suitable habitat for wild seabream populations in the Adriatic Sea. This altered environment, characterised by different hydrodynamics and prey availability compared to natural habitats, has triggered a specific phenotypic response of seabream by forming a new morphotype associated with tuna farms. The smaller and blunt head and the more spindle-shaped body are the main characteristics of the mentioned morphotype. In the vicinity of tuna farms, the sex change of seabream has been documented at lower lengths compared to wild populations, due to the significant trophic support that ensures better condition and reproductive status. When observing wild and farmed seabream, geometric morphometrics methods successfully assigned 99.6% of individuals to their correct origin in terms of body shape and more than 70% in terms of otolith shape. A rounder head profile with a supraterminal positioned mouth and a stocky body shape with darker and paler silver-grey coloration are the main characteristics of farmed seabream, while wild individuals are described with an elongated body and a subterminal mouth on a larger head profile. The information collected in this research can be used in future biotechnological research to identify the origin of fish through machine learning and, in the long term, in the management of escapes and the development of selection programmes for aquaculture species

Morphological and molecular differentiation of wild and farmed gilthead sea bream Sparus aurata: implications for management

A combination of molecular and morphological characteristics was used to investigate populations of wild and farmed gilthead sea bream Sparus aurata from the largest Croatian shellfish production area, Mali Ston Bay. Identification of farmed escapees was performed in the wild in order to evaluate and compare the detection sensitivity of molecular and morphological tools. Using a traditional set of measurements and a truss network system, morphometric trait analysis of gilthead sea bream showed clear body shape differences between individuals from the wild and farmed populations. Microsatellite markers only revealed weak neutral genetic differentiation between farmed and wild samples from Mali Ston Bay (Wright’s FST = 0.019, p > 0.05; Jost’s DEST = 0.022), despite the fact that the farmed gilthead sea bream were of Atlantic origin. Using assignment tests, morphological (16%) and molecular (25%) analysis identified farmed escapees in the samples of wild gilthead sea bream in the vicinity of aquaculture sites. Morphological data showed good potential for distinguishing recent escapees in wild populations, since these characteristics are affected by the environment. This study demonstrates the presence of escapees in the local wild population in this region, and suggests the potential for genetic interaction

Tissue preservation can affect geometric morphometric analyses: a case study using fish body shape

International audienceIn geometric morphometrics, the extent of variation attributable to non-biological causes (i.e. measurement error) is sometimes overlooked. The effects of this variation on downstream statistical analyses are also largely unknown. In particular, it is unclear whether specimen preservation induces substantial variation in shape and whether such variation affects downstream statistical inference. Using a combination of empirical fish body shape data and realistic simulations, we show that preservation introduces substantial artefactual variation and significant non-random error (i.e. bias). Most changes in shape occur when fresh fish are frozen and thawed, whereas a smaller change in shape is observed when frozen and thawed fish are fixed in formalin and transferred to ethanol. Surprisingly, we also show that, in our case, preservation produces only minor effects on three downstream analyses of shape variation: classification using canonical variate analysis, permutation tests of differences in means and computations of differences in mean shape between groups. Even mixing of differently preserved specimens has a relatively small effect on downstream analyses. However, we suggest that mixing fish with different preservation should still be avoided and discuss the conditions in which this practice might be justified