Incorporating evolutionary based tools in cephalopod fisheries management

With gradual decline of global finfish resources, fisheries targeting cephalopods expanded. Yet, the stock assessment and management practice are frequently lacking, and existing ones often remain poorly suited for cephalopod unique life-history. In light of increasing ecological disturbances in marine ecosystems worldwide, assessing exploited species’ status and response becomes vital for devising effective strategies that would ensure their sustainable management. There is generally scarce understanding of the way fisheries and other environmental stressors exert their combined effects on cephalopods stock dynamic and long-term resilience. To that end, evolutionary-based population studies that inform on identity, connectivity and adaptive potential of natural populations present a unique opportunity for assessing the viability of exploited cephalopod stocks. Such studies have been revolutionized in the last decade by proliferation of next generation sequencing technologies. They offer new avenues for expanding our knowledge, especially on population structure and the evolutionary responses to shifts in environmental pressures. In this paper we elaborate on how deep genomic insights into demographic and evolutionary status of fished cephalopods could improve their stock assessment and management practice. We also propose that the common octopus Octopus vulgaris would be a suitable model species to test the power of evolutionary tools to inform fishery scientists and managers on biological questions relevant for their sustainable exploitation.Fundação para a Ciência e Tecnologia - FCTinfo:eu-repo/semantics/publishedVersio

različiti učinci radiofrekvencijskog elektromagnetskog polja na ličinke medonosne pčele (Apis mellifera) u ovisnosti o oblikovanju pokusa

Exposure to radiofrequency electromagnetic fields (RF-EMF) at the operating frequencies of different communication devices can cause various biological effects. However, there is a lack of studies on the oxidative stress response and genotoxicity in the honey bee (Apis mellifera) after exposure to RF-EMF. In this study, we investigated the oxidative stress and DNA damage in honey bee larvae situated in waxcomb cells, exposed to modulated RF-EMF 23 Vm-1. The glutathione S-transferase activity decreased, whereas the catalase activity increased significantly in the honey bee larvae upon RF-EMF exposure. Superoxide dismutase activity, the level of lipid peroxidation, and DNA damage were not statistically altered in exposed honey bee larvae when compared to the control group. These results suggest that the biological effects of modulated RF-EMF in honey bee larvae depend on the exposure design.Izloženost radiofrekvencijskom elektromagnetskom polju (RF-EMF) na radnoj frekvenciji različitih komunikacijskih uređaja može imati razne biološke učinke. Nedostaju istraživanja odgovora na oksidacijski stres i genotoksičnost u medonosne pčele (Apis mellifera) poslije izloženosti RF-EMF-u. U ovom je radu istražen oksidacijski stres i DNA oštećenja u ličinkama medonosnih pčela smještenih u stanicama saća i izloženih modulirajućem RF-EMF 23 Vm-1. Aktivnost glutation S-transferaze smanjena je, dok je aktivnost katalaze značajno povećana u ličinkama medonosnih pčela izloženih RF-EMF-u. Nije bilo statistički značajne promjene u aktivnosti superoksid-dismutaze, razini lipidne peroksidacije i DNA oštećenju između ličinaka medonosne pčele i kontrolne skupine. Ovi rezultati pokazuju da biološki učinci modulirajućeg RF-EMF u ličinkama medonosne pčele ovise o oblikovanju izloženosti

Kavezno izlaganje lubina (Dicentrarchus labrax) u procjeni genotoksičnog utjecaja onečišćenja

Genotoxic effects are often the earliest signs of pollution-related environmental disturbance. In this study, we used the comet assay and micronucleus test to assess DNA damage in the erythrocytes of the European sea bass (Dicentrarchus labrax) exposed to environmental pollution in situ. Fish were collected from a fi sh farm in the Trogir Bay and their cages placed at an unpolluted reference site Šolta (Nečujam Bay) and a polluted site Vranjic (Kaštela Bay) for four weeks. A group of fi sh which remained at the fi sh farm Trogir Bay were used as the second control group. Fish exposed at the Vranjic site showed a signifi cantly higher erythrocyte DNA damage, measured by the comet assay, than either control group. Micronucleus induction showed a similar gradient of DNA damage, but did not reach statistical signifi cance. Our results show that cage exposure of a marine fi sh D. labrax can be useful in environmental biomonitoring and confi rm the comet assay as a suitable tool for detecting pollution-related genotoxicity.Genotoksični učinak često je jedan od najranijih pokazatelja štetnog djelovanja onečišćenja okoliša. U ovom radu procijenjeno je oštećenje DNA u eritrocitima lubina (Dicentrarchus labrax) izloženima okolišnom onečišćenju s pomoću komet-testa i mikronukleus-testa. Lubini su prikupljeni na ribogojilištu i kavezno izloženi u periodu od četiri tjedna na dvije postaje različitog stupnja onečišćenja na jadranskoj obali: na kontrolnoj postaji Šolta (zaljev Nečujam) i na onečišćenoj postaji Vranjic (Kaštelanski zaljev). Zasebna skupina lubina skupljena na ribogojilištu poslužila je kao druga kontrola. Rezultati komet-testa pokazali su statistički značajan porast oštećenja DNA na postaji Vranjic u usporedbi s obje kontrolne postaje. Rezultati mikronukleus-testa pokazali su sličan gradijent onečišćenja, iako nisu dosegli statističku značajnost. Ovi rezultati upućuju na primjenjivost kaveznog izlaganja lubina D. labrax u biomonitoringu vodenog okoliša te potvrđuju korisnost komet-testa kao prikladne metode za detekciju genotoksičnog utjecaja onečišćenja

Wolf spiders (Araneae: Lycosidae) on the overgrowing peat bog in Dubravica (north-western Croatia)

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Zebrafish genome instability after exposure to model genotoxicants

International audienceSublethal exposure to environmental genotoxicants may impact genome integrity in affected organisms. It is therefore necessary to develop tools to measure the extent and longevity of genotoxicant-induced DNA damage, and choose appropriate model organisms for biomonitoring. To this end, markers of DNA damage were measured in zebrafish larvae and adults following exposure to model genotoxicants (benzo[a]pyrene and ethyl methanesulfonate). Specifically, we assessed primary DNA damage and the existence of potentially persistent genomic alterations through application of the comet assay, quantitative random amplified polymorphic DNA (qRAPD) and amplified fragment length polymorphism (AFLP) assays. Furthermore, expression of genes involved in DNA repair, oxidative stress response and xenobiotic metabolism was evaluated as well. Additionally, the AFLP method was applied to adult specimens 1 year after larval exposure to the genotoxicants to evaluate the longevity of the observed DNA alterations. Large numbers of DNA alterations were detected in larval DNA using the comet assay, qRAPD and AFLP, demonstrating that zebrafish larvae are a sensitive model for revealing genotoxic effects. Furthermore, some of these genomic alterations persisted into adulthood, indicating the formation of stable genomic modifications. qRAPD and AFLP methods proved to be highly sensitive to genotoxic effects, even in cases when the comet assay indicated a lack of significant damage. These results thus support the use of zebrafish larvae as a sensitive model for monitoring the impact of genotoxic insult and give evidence of the longevity of genomic modifications induced by genotoxic agents

Effects of freshwater pollution on the genetics of zebra mussels (Dreissena polymorpha) at the molecular and population level

Revealing long-term effects of contaminants on the genetic structure of organisms inhabiting polluted environments should encompass analyses at the population, molecular, and cellular level. Following this concept, we studied the genetic constitution of zebra mussel populations from a polluted (Dp) and reference sites (Cl) at the river Drava, Croatia, and applied microsatellite and DNA damage analyses (Comet assay, micronucleus test (MNT)). Additionally, mussels from both populations were exposed to polluted wastewater in the laboratory for three days, and DNA damage was analyzed to evaluate acclimatization and genetic adaptation of the investigated populations to the polluted environment. The two populations differed in their genetic constitution. Microsatellite analysis suggested that Dp had undergone a genetic bottleneck. Comet assay did not indicate any difference in DNA damage between the two populations, but MNT revealed that Dp had an increased percentage of micronuclei in hemocytes in comparison to Cl. The laboratory experiment revealed that Dp had a lower percentage of tail DNA and a higher percentage of micronuclei than Cl. These differences between populations were possibly caused by an overall decreased fitness of Dp due to genetic drift and by an enhanced DNA repair mechanism due to acclimatization to pollution in the source habitat

From micro to macroevolution: drivers of shape variation in an island radiation of Podarcis lizards

Phenotypictraits have been shown to evolve in response to variation in the environment. However, the evolutionary processes underlying the emergence of phenotypic diversity can typically only be understood at the population level. Consequently, how subtle phenotypic differences at the intraspecific level can give rise to larger-scale changes in performance and ecology remains poorly understood. We here tested for the covariation between ecology, bite force, jaw muscle architecture, and the three-dimensional shape of the cranium and mandible in 16 insular populations of the lizards Podarcis melisellensis and P. sicula. We then compared the patterns observed at the among-population level with those observed at the interspecific level. We found that three-dimensional head shape as well as jaw musculature evolve similarly under similar ecological circumstances. Depending on the type of food consumed or on the level of sexual competition, different muscle groups were more developed and appeared to underlie changes in cranium and mandible shape. Our findings show that the local selective regimes are primary drivers of phenotypic variation resulting in predictable patterns of form and function. Moreover, intraspecific patterns of variation were generally consistent with those at the interspecific level, suggesting that microevolutionary variation may translate into macroevolutionary patterns of ecomorphological diversity

Linking micro and macroevolution of head shape in an island radiation

Phenotypic traits have been shown to evolve in response to variation in the environment. However, the evolutionary processes underlying the emergence of phenotypic diversity can typically only be understood at the population level. Consequently, how subtle phenotypic differences at the intraspecific level can give rise to larger-scale changes in performance and ecology remains poorly understood. We here tested for the covariation between ecology, bite force, jaw muscle architecture, and the three-dimensional shape of the cranium and mandible in 16 insular populations of the lizards Podarcis melisellensis and P. sicula. We then compared the patterns observed at the among-population level with those observed at the interspecific level. We found that three-dimensional head shape as well as jaw musculature evolve similarly under similar ecological circumstances. Depending on the type of food consumed or on the level of sexual competition, different muscle groups were more developed and appeared to underlie changes in cranium and mandible shape. Our findings show that the local selective regimes are primary drivers of phenotypic variation resulting in predictable patterns of form and function. Moreover, intraspecific patterns of variation were generally consistent with those at the interspecific level, suggesting that microevolutionary variation may translate into macroevolutionary patterns of ecomorphological diversity.,In-vivo bite force, diet and intrapopulation competition levels were investigated throughout 16 insular and mainland populations of Podarcis lizards. Data was acquired on the field and animals released, although 5 females and 5 males of each population were sacrificed, fixed in formalin and CT scanned. Their jaw musculature was then dissected to quantify variation in muscle architecture. The scans were used to reconstruct cranial and mandible 3D surface which were subsequently analysed with geometric morphometrics approach.

Diet variability among insular populations of Podarcis lizards reveals diverse strategies to face resource‐limited environments

International audienc

Local Ecological Knowledge (LEK) as a support for Octopus vulgaris fisheries management

Forum on Fisheries Science in the Mediterranean and The Black Sea (FishForum 2018), 10-14 December 2018, Rome, ItalyFishermen’s Local Ecological Knowledge (LEK), when documented, may play an important role in documenting fishing practices, enhancing the understanding of ecological changes and scientific data. Furthermore, through targeted questions, researchers and managers can get information on several social and economic features of fisheries and their value for the local communities, contributing to create improved management plans. We developed a questionnaire to gather LEK information, from fishing activities and species’ ecology to fishermen perception on fisheries management and impacts. The survey, carried out in 2017, focused on Octopus vulgaris fishery involving three fishing communities in Komiža (Croatia), Patti (Sicily, Italy) and Palamós (Cataluña, Spain), resulting in a total of 47 interviews. In these areas octopus was targeted in multispecific and multigear fisheries, with clear seasonality patterns. O. vulgaris was never the single target species, and its relevance for fishermen decreased from Palamós to Patti and Komiža communities. In all areas fishermen reported a decline in octopus catches. In particular they pointed to recreational and illegal fishing as the worst source of impact, affecting the stock and determining economic losses. According to fishermen perception the impact of this activity seems to be higher than marine pollution, requiring an increase in controls by the authorities. The majority of fishermen consider to be duly involved in setting rules and management processes, though there is the need to increase collaboration with researchers and policy makers to enforce effective management measures at local levelPeer Reviewe