scholarly journals Spoiled for Choice during Cold Season? Habitat Use and Potential Impacts of the Invasive Silurus glanis L. in a Deep, Large and Oligotrophic Lake (Lake Maggiore, North Italy)

2021 ◽  
Author(s):  
Vanessa De Santis ◽  
Pietro Volta
Keyword(s):  
Invasive Alien Species ◽  
Cold Season ◽  
Effective Management ◽  
Prey Fish ◽  
Silurus Glanis ◽  
Ecological Information ◽  
Lake Maggiore ◽  
European Catfish ◽  
First Time ◽  
Infor Mation

Ecological information of invasive alien species are crucial for their effective management. How-ever, they are often lacking in newly invaded ecosystems. This is the case of the European catfish Silurus glanis L. in Lake Maggiore where the species is present since 1990 but no scientific infor-mation are available on its ecology. To start filling this knowledge gap, 236 catfish (67 cm to 150 cm of total length) were collected, measured, and dissected for stomach content analyses from three localities and in two habitats (littoral vs. pelagic) in late autumn/early winter. NPUE and BPUE (individuals and biomass (g) per unit effort (m2)) of catfish was generally higher in littoral (NPUE > 0.01; BPUE > 96) than pelagic habitats (NPUE < 0.009; BPUE < 114) but catfish had, on average, larger sizes in pelagic habitats. Overall, 581 individual prey items were recorded belonging to12 taxa. Pelagic catfish specialized their diet exclusively on three prey fish (coregonids, shad and roach) whilst the diet of littoral catfish was more variable, and was dominated by crayfish, perch, and roach. These results highlighted for the first time the interaction of larger catfish with the lake’s pelagic food web, and thus possible consequences are discussed, including the potential contrasting role S. glanis may have for the lake’s fishery.

scholarly journals Spoiled for Choice during Cold Season? Habitat Use and Potential Impacts of the Invasive Silurus glanis L. in a Deep, Large, and Oligotrophic Lake (Lake Maggiore, North Italy)

Water ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 2549
Author(s):  
Vanessa De Santis ◽  
Pietro Volta
Keyword(s):  
Invasive Alien Species ◽  
Scientific Information ◽  
Cold Season ◽  
Effective Management ◽  
Prey Fish ◽  
Silurus Glanis ◽  
Lake Maggiore ◽  
Ecological Features ◽  
European Catfish ◽  
First Time

The ecological features of invasive alien species are crucial for their effective management. However, they are often lacking in newly invaded ecosystems. This is the case of the European catfish Silurus glanis L. in Lake Maggiore, where the species is present since 1990, but no scientific information is available on its ecology. To start filling this knowledge gap, 236 catfish (67 cm to 150 cm of total length) were collected, measured, and dissected for stomach content analyses from three localities and in two habitats (littoral vs. pelagic) in late autumn/early winter. The NPUE and BPUE (individuals (N) and biomass (B, in grams) per unit effort (m2), respectively) of catfish were generally higher in littoral (NPUE > 0.01; BPUE > 96) than in pelagic habitats (NPUE < 0.009; BPUE < 114), but the catfish had, on average, larger sizes in pelagic habitats. Overall, 581 individual prey items were recorded, belonging to 12 taxa. Pelagic catfish specialized their diet exclusively on three prey fish (coregonids, shad, and roach), whilst the diet of littoral catfish was more variable and dominated by crayfish, perch, and roach. These results highlighted for the first time the interaction of larger catfish with the lake’s pelagic food web, and thus possible consequences are discussed, including the potential contrasting role S. glanis may have for the lake’s fishery.

scholarly journals One Year Monitoring of Ecological Interaction of Silurus glanis in a Novel Invaded Oligotrophic Deep Lake (Lake Maggiore)

Water ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 105
Author(s):  
Caterina M. Antognazza ◽  
Tommaso Costantini ◽  
Monica Campagnolo ◽  
Serena Zaccara
Keyword(s):  
Stomach Contents ◽  
High Growth ◽  
High Growth Rate ◽  
Trophic Levels ◽  
Prey Fish ◽  
Silurus Glanis ◽  
Orconectes Limosus ◽  
Lake Maggiore ◽  
European Catfish ◽  
Aquatic Food

The European catfish (Silurus glanis) was introduced in Italy during the last century for aquaculture purposes, and now it is well-established. S. glanis is an invasive species and a top predator that can deplete prey supply in the surrounding habitat, leading to changes in the aquatic food web. Consequently, its presence is considered a threat to native fish populations. Its presence in the Lake Maggiore (Northern Italy) is recent and there is a lack of knowledge about its ability to completely exploit this new ecosystem throughout the year. This study corroborated the ability of European catfish to exploit both pelagic and littoral habitats, promoting trophic interactions in both habitats. Over 2019, multiple sampling approaches have been applied by collecting S. glanis and analysing its stomach contents with the aim of inferring interactions with the freshwater community. Its diet was mainly based on crayfish (Orconectes limosus), followed by six prey fish and the genus Corbicula; two fish species (Padogobius bonelli and Salaria fluviatilis) were added to the list of known prey fish. Notably and alarmingly for the early potential top-down pressure towards all trophic levels, young individuals were proved to also feed on fish and crayfish. S. glanis showed the ability to hunt at deep depths (>60 m) and a high growth rate, despite Lake Maggiore being oligotrophic.

scholarly journals Ecological Observations on Hybrid Populations of European Plethodontid Salamanders, Genus Speleomantes

Diversity ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 285
Author(s):  
Enrico Lunghi ◽  
Fabio Cianferoni ◽  
Stefano Merilli ◽  
Yahui Zhao ◽  
Raoul Manenti ◽  
...  
Keyword(s):  
Body Condition ◽  
Parental Species ◽  
Stomach Contents ◽  
Trophic Niche ◽  
Natural Hybrid ◽  
Ecological Information ◽  
Total Length ◽  
Plethodontid Salamanders ◽  
The Future ◽  
First Time

Speleomantes are the only plethodontid salamanders present in Europe. Multiple studies have been performed to investigate the trophic niche of the eight Speleomantes species, but none of these studies included hybrid populations. For the first time, we studied the trophic niche of five Speleomantes hybrid populations. Each population was surveyed twice in 2020, and stomach flushing was performed on each captured salamander; stomach flushing is a harmless technique that allows stomach contents to be inspected. We also assessed the potential divergence in size and body condition between natural and introduced hybrids, and their parental species. Previously collected data on Speleomantes were included to increase the robustness of these analyses. In only 33 out of 134 sampled hybrid Speleomantes we recognized 81 items belonging to 11 prey categories. The frequency of empty stomachs was higher in females and individuals from natural hybrid populations, whereas the largest number of prey was consumed by males. We compared the total length and body condition of 685 adult salamanders belonging to three types of hybrids and three parental (sub)species. Three group of salamanders (one hybrid and two parental species) showed significantly larger size, whereas no difference in body condition was observed. This study provided novel ecological information on Speleomantes hybrid populations. We also provided insights into the potential divergence between hybrids and parental species in terms of size and body condition. We discuss our findings, and formulate several hypotheses that should be tested in the future.

scholarly journals First record of Dero (Aulophorus) bimagnasetus Harman (Oligochaeta) from Brazil and habitat characteristics

2014 ◽  
Vol 74 (2) ◽  
pp. 483-488
Author(s):  
R. Campitelli-Ramos ◽  
JV. Lucca ◽  
LLD. Oliveira ◽  
MR. Marchese ◽  
O. Rocha
Keyword(s):  
Benthic Communities ◽  
First Record ◽  
Biological Data ◽  
Habitat Characteristics ◽  
Low Oxygen ◽  
Body Width ◽  
Ecological Information ◽  
Freshwater Biota ◽  
Physical And Chemical ◽  
First Time

Annelid worms represent a significant part of freshwater benthic communities worldwide and Oligochaeta is a particularly species-rich group. Dero (A) bimagnasetus (Naididae) previously found and described from a small marsh in Surinam in 1974, has now been found for the first time in Barra Lake, MG, Brazil. Due to the scarce biological data and absence of ecological information in the literature regarding this species we are presenting morphological information on the specimens obtained and the physical and chemical characteristics of the habitat they were found. This species occurred only in the littoral zone of Barra Lake, in muddy, low oxygen, low conductivity and low organic matter sediment. The four individuals collected ranged 3.17-4.15 mm total length; 0.25 - 0.26 mm body width and 0.16-0.21 mm3 total volume. Considering the present anthropic pressures on freshwater biota and fast biodiversity losses worldwide it is now recognized that attention must be paid to low abundance species and the urgency for preservation of their habitats.

scholarly journals APPLYING OF ACTIVITIES MANAGEMENT BASED ON SELF-LEARNING

2018 ◽  
Vol 1 ◽  
pp. 29-38 ◽  
Author(s):  
Valerii Samsonkin ◽  
Valerii Druz’ ◽  
Albert Feldman
Keyword(s):  
Quality Management ◽  
Technological Process ◽  
Human Activities ◽  
System Approach ◽  
Human Operator ◽  
Statistical Regularity ◽  
Effective Management ◽  
The Individual ◽  
First Time ◽  
Self Learning

The article is devoted to a brief presentation and application in practice of an effective management way of human activities and human-technical communities one. This way was called Method of statistical regularity (Method of self-organizing processes). In fact, this is a system approach. For the first time, the application of this approach is shown on the example of quality management of the technological process. Practical management is shown using an algorithm. The effectiveness of the author's system approach is explained by the consideration of the final result of the activity as a goal and a system-forming factor of activity, taking into account the individual features of the management object, real statistics of activity. The system approach described in the article is a universal devise of management. It can be used and already used to manage individual functions of the enterprise, the process, the human operator, the community

Taxonomical clarification of Tetrix gibberosa (Wang & Zheng), a high-backed pygmy grasshopper species from eastern PR China (Orthoptera: Tetrigidae)

Zootaxa ◽  
2021 ◽  
Vol 5082 (3) ◽  
pp. 278-285
Author(s):  
WEN-JING DING ◽  
JIAN-HUA DING ◽  
HAI-JUN ZHANG ◽  
LING-SHENG ZHA
Keyword(s):  
Grasshopper Species ◽  
Ecological Information ◽  
New Synonyms ◽  
Pr China ◽  
Length Changes ◽  
First Time

Tetrix gibberosa (Wang & Zheng) is a high-backed pygmy grasshopper species from eastern PR China. Due to its reduced hind wings and pleomorphism (length changes of hind wings and the hind pronotal process, which is generally called macropterous and brachypterous morphs), the species have been described into different species which involve several taxonomically confused genera. This study clarifies its taxonomy and distribution and provides ecological information for the species. At the same time, we comment the relationships of related genera in the subfamily Tetriginae, including Tetrix Latreille, Exothotettix Zheng & Jiang, Alulatettix Liang, Aalatettix Zheng & Mao, Formosatettix Tinkham, and Formosatettixoides Zheng. Additionally, we report for the first time that nematodes can parasitize pygmy grasshoppers. New synonyms are proposed: Tetrix gibberosa (Wang & Zheng, 1993) = Alulatettix bulbosus Zheng & Zhong, 2001, syn. nov., = Exothotettix jiangxiensis Liang & Jia, 2008, syn. nov., = Tetrix glochinota Zhao, Niu & Zheng, 2010, syn. nov., = Alulatettix nigromarginalis Zhang, Deng & Zha, 2014, syn. nov., = Alulatettix flavotibialis Zhang, Deng & Zha, 2014, syn. nov..  

AQUA_2020_1080: Sperm management of European catfish (Silurus glanis L.) for effective reproduction and genetic conservation

Aquaculture ◽  
2020 ◽  
Vol 529 ◽  
pp. 735620 ◽  
Author(s):  
Otomar Linhart ◽  
Yu Cheng ◽  
Marek Rodina ◽  
David Gela ◽  
Vladimíra Tučková ◽  
...  
Keyword(s):  
Genetic Conservation ◽  
Silurus Glanis ◽  
European Catfish
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