Ecology, behaviour and management of the European catfish

The extreme body sizes of megafishes associated with their high commercial values and recreational interests have made them highly threatened in their native range worldwide by human-induced impacts such as overexploitation. Meanwhile, some megafishes have been introduced outside of their native range. A notable example is the European catfish (Silurus glanis), one of the few siluriforms native to Eastern Europe. It is among the 20 largest freshwater fish worldwide, attaining a total length over 2.7 m and a documented mass of 130 kg. Its distinct phylogeny and extreme size imply many features that are rare among other European fish, including novel behaviours (massive aggregations, beaching), consumption of large bodied prey, fast growth rates, long lifespan, high fecundity, nest guarding and large egg sizes. The spread of the species is likely to continue due to illegal introductions, primarily for recreational angling, coupled with natural range extension associated with climate change. Here, the most recent knowledge on the current distribution and the ecology of the species are reviewed. A series of key research questions are identified that should stimulate new rese arch on this intriguing, yet largely unknown, species and, more generally, on the ecology of freshwater invadersThis work was produced as part of the ‘‘European Catfish Working Group’’ that was financially supported by the University of Toulouse. Individual members of the group were supported by the Spanish Ministry of Economy and Competitiveness (Project CGL2013-43822-R), the Government of Catalonia (ref. 2014 SGR 484), the European Commission (COST Action TD1209), Czech Science Foundation (Project 16-06498S) and the French Laboratory of Excellence Project ‘‘TULIP’’ (ANR-10-LABX-41; ANR-11-IDEX-0002-02

Stanovení histaminu v silážích za použití nanomaghemitového jádra (-Fe2O3)-nanočástic oxidu titaničitého off-line spojených s iontoměničovou chromatografií

The presence of biogenic amines is a hallmark of degraded food and its products. Herein, we focused on the utilization of magnetic nanoparticles off-line coupled with ion exchange chromatography with post-column ninhydrin derivatization and Vis detection for histamine (Him) separation and detection. Primarily, we described the synthesis of magnetic nanoparticles with nanomaghemite core (-Fe2O3) functionalized with titanium dioxide and, then, applied these particles to specific isolation of Him. To obtain further insight into interactions between paramagnetic particles’ (PMP) surface and Him, a scanning electron microscope was employed. It was shown that binding of histamine causes an increase of relative current response of deprotonated PMPs, which confirmed formation of Him-PMPs clusters. The recovery of the isolation showed that titanium dioxide-based particles were able to bind and preconcentrate Him with recovery exceeding 90%. Finally, we successfully carried out the analyses of real samples obtained from silage. We can conclude that our modified particles are suitable for Him isolation, and thus may serve as the first isolation step of Him from biological samples, as it is demonstrated on alfalfa seed variety Tereza silage.Přítomnost biogenních aminů je charakteristickým znakem znehodnocených potravin a jejich produktů. Zde jsme se zaměřili na využití magnetických nanočástic off-line spojených s iontoměničovou chromatografií s postkolonovou derivatizací ninhydrinem a Vis detekcí pro separaci a detekci histaminu (Him). V první řadě jsme popsali syntézu magnetických nanočástic s nanomaghemitovým jádrem (-Fe2O3) funkcionalizovaných s oxidem titaničitým, poté jsme aplikovali tyto částice na specifickou izolaci Him. K získání dalšího vhledu do interakce mezi povrchem paramagnetických částic (PMP) a Him byl použit skenovací elektronový mikroskop. Bylo ukázáno, že vazba histaminu způsobuje zvýšení relativní aktuální odezvy deprotonovaných PMPs, což potvrdilo tvorbu Him-PMPs clusterů. Využití izolace ukázalo, že částice na bázi oxidu titaničitého byly schopny vázat a prekoncentrovat Him s celkovým výtěžkem vyšším než 90%. Nakonec jsme úspěšně provedli analýzy reálných vzorků získaných ze siláže. Můžeme usuzovat, že naše modifikované částice jsou vhodné pro izolaci Him a tak mohou sloužit jako první krok pro izolaci Him z biologických vzorků, jak je demonstrováno na siláži semen vojtěšky odrůdy Tereza