Intrahepatic branching of the portal vein in the Eurasian otter (Lutra lutra) and American mink (Neovison vison)

In the UK, the native European otter (Lutra lutra) and invasive American mink (Neovison vison) have experienced concurrent declines and expansions. Currently, the otter is recovering from persecution and waterway pollution, whereas the mink is in decline due to population control and probable interspecific interaction with the otter. We explored the potential of DNA metabarcoding for investigating diet and niche partitioning between these mustelids. Otter spraints (n = 171) and mink scats (n = 19) collected from three sites (Malham Tarn, River Hull and River Glaven) in northern and eastern England were screened for vertebrates using high-throughput sequencing. Otter diet mainly comprised aquatic fishes (81.0%) and amphibians (12.7%), whereas mink diet predominantly consisted of terrestrial birds (55.9%) and mammals (39.6%). The mink used a lower proportion (20%) of available prey (n = 40 taxa) than the otter and low niche overlap (0.267) was observed between these mustelids. Prey taxon richness of mink scats was lower than otter spraints and beta diversity of prey communities was driven by taxon turnover (i.e. the otter and mink consumed different prey taxa). Considering otter diet only, prey taxon richness was higher in spraints from the River Hull catchment and beta diversity of prey communities was driven by taxon turnover (i.e. the otter consumed different prey taxa at each site). Studies using morphological faecal analysis may misidentify the predator as well as prey items. Faecal DNA metabarcoding can resolve these issues and provide more accurate and detailed dietary information. When scaled up across multiple habitat types, DNA metabarcoding should greatly improve future understanding of resource use and niche overlap between the otter and mink.

Download Full-text

Biliary parasite Pseudamphistomum truncatum (Opistorchiidae) in American mink (Mustela vison) and Eurasian otter (Lutra lutra) in Ireland

Parasitology Research ◽

10.1007/s00436-010-1951-6 ◽

2010 ◽

Vol 107 (4) ◽

pp. 993-997 ◽

Cited By ~ 6

Author(s):

Conall J. Hawkins ◽

Joe M. Caffrey ◽

Peter Stuart ◽

Colin Lawton

Keyword(s):

American Mink ◽

Mustela Vison ◽

Lutra Lutra ◽

Eurasian Otter

Download Full-text

Using DNA metabarcoding to investigate diet and niche partitioning in the native European otter (Lutra lutra) and invasive American mink (Neovison vison)

10.1101/2020.07.03.186346 ◽

2020 ◽

Author(s):

Lynsey R. Harper ◽

Hayley V. Watson ◽

Robert Donnelly ◽

Richard Hampshire ◽

Carl D. Sayer ◽

...

Keyword(s):

Beta Diversity ◽

American Mink ◽

Niche Partitioning ◽

Niche Overlap ◽

Neovison Vison ◽

Lutra Lutra ◽

Taxon Richness ◽

Prey Taxon ◽

Dna Metabarcoding ◽

European Otter

AbstractIn the UK, the native European otter (Lutra lutra) and invasive American mink (Neovison vison) have experienced concurrent declines and expansions. Currently, the otter is recovering from persecution and waterway pollution, whereas the mink is in decline due to population control and probable interspecific interaction with the otter. We explored the potential of DNA metabarcoding for investigating diet and niche partitioning between these mustelids. Otter spraints (n = 171) and mink scats (n = 19) collected from three sites (Malham Tarn, River Hull, and River Glaven) in northern and eastern England were screened for vertebrates using high-throughput sequencing. Otter diet mainly comprised aquatic fishes (81.0%) and amphibians (12.7%), whereas mink diet predominantly consisted of terrestrial birds (55.9%) and mammals (39.6%). The mink used a lower proportion (20%) of available prey (n = 40 taxa) than the otter, and low niche overlap (0.267) was observed between these mustelids. Prey taxon richness of mink scats was lower than otter spraints, and beta diversity of prey communities was driven by taxon turnover (i.e. the otter and mink consumed different prey taxa). Considering otter diet only, prey taxon richness was higher in spraints from the River Hull catchment, and beta diversity of prey communities was driven by taxon turnover (i.e. the otter consumed different prey taxa at each site). Studies using morphological faecal analysis may misidentify the predator as well as prey items. Faecal DNA metabarcoding can resolve these issues and provide more accurate and detailed dietary information. When upscaled across multiple habitat types, DNA metabarcoding should greatly improve future understanding of resource use and niche overlap between the otter and mink.

Download Full-text

Helminths of mustelids with overlapping ecological niches: Eurasian otter Lutra lutra (Linnaeus, 1758), American mink Neovison vison Schreber, 1777, and European polecat Mustela putorius Linnaeus, 1758

Helminthologia ◽

10.2478/helm-2018-0035 ◽

2019 ◽

Vol 56 (1) ◽

pp. 66-74 ◽

Cited By ~ 3

Author(s):

D. Nugaraitė ◽

V. Mažeika ◽

A. Paulauskas

Keyword(s):

American Mink ◽

Helminth Species ◽

Water Bodies ◽

Ecological Niches ◽

Lutra Lutra ◽

Mustela Putorius ◽

Opisthorchis Felineus ◽

Alaria Alata ◽

Eurasian Otter ◽

Higher Taxa

SummaryThis study presents the helminthological data on three mustelid species with overlapping ecological niches in Lithuania. In general, 14 helminth species or higher taxa were reported from all mustelids: Isthmiophora melis, Strigea strigis metacercariae, Pseudamphistomum truncatum, Alaria alata mesocercariae, Phyllodistomum folium, Opisthorchis felineus, Metametorchis skrjabini, Mesocestoides sp., Taenia martis, Aonchotheca putorii, Crenosoma schachmatovae, Eucoleus aerophilus, Molineus patens, and Nematoda g. sp. The largest number of helminths was detected in M. putorius (11) and N. vison (10) from wetlands; 7 helminths were detected in M. putorius from forests, and 8 in N. vison and 4 in L. lutra from water bodies. Habitat-related differences were found in the abundance and prevalence of E. aerophilus in M. putorius. M. putorius has higher indices of infection by I. melis, S. strigis metacercariae, and E. aerophilus compared to N. vison in wetlands. Differences in the abundance and prevalence of P. truncatum among N. vison and L. lutra in water bodies have been observed. Helminths detected in N. vison in the present study are native European parasites.

Download Full-text

Pulmonary hair embolism in a rescued free-ranging Eurasian otter Lutra lutra in Kinmen, Taiwan

Diseases of Aquatic Organisms ◽

10.3354/dao03532 ◽

2020 ◽

Vol 142 ◽

pp. 55-61

Author(s):

WT Li ◽

YL Chiang ◽

TY Chen ◽

CL Lai

Keyword(s):

Foreign Body ◽

Traumatic Injury ◽

Lung Parenchyma ◽

Giant Cells ◽

Hair Shaft ◽

Lutra Lutra ◽

Lung Lobe ◽

Eurasian Otter ◽

Foreign Body Giant Cells ◽

Free Ranging

Eurasian otters Lutra lutra are listed as Near Threatened on the IUCN Red List and are imperiled by habitat loss, water pollution, and poaching. Harassment and attacks by stray animals are also recognized threats to the health of wild Eurasian otters. Pulmonary hair embolism is a possible complication in animals with deep traumatic injury, but to date no cases have been reported in wildlife. A free-ranging, adult male Eurasian otter was rescued due to severe emaciation and multiple bite wounds. The otter died 3 d after rescue and was necropsied. Grossly, a 1.5 × 1.5 × 1.5 cm firm nodule was observed in the left cranial lung lobe. Histologically, a fragment of hair shaft surrounded by multinucleated foreign body giant cells was observed in a medium-sized vein, and extensive eosinophilic infiltration was noted in the adjacent vascular wall and lung parenchyma. Based on the gross and histological findings, the pulmonary lesion was consistent with eosinophilic pneumonia and vasculitis induced by hair embolism. The presence of well-formed multinucleated foreign body giant cells and eosinophils may imply a late stage of foreign body reaction, and thus the presumptive source of hair embolism is an animal bite. This is the first report of pulmonary hair embolism associated with animal bite in a rescued free-ranging Eurasian otter.

Download Full-text