Morphological differences between free-living soil and freshwater nematodes in relation to their environments

Nematology ◽  
2020 ◽  
Vol 22 (2) ◽  
pp. 125-132
Author(s):  
Aldo Zullini ◽  
Federica Semprucci
Keyword(s):  
Species Differences ◽  
Soil Nematodes ◽  
Aquatic Species ◽  
Free Living ◽  
European Species ◽  
Quantitative Characters ◽  
Freshwater Nematodes ◽  
Body Parameter ◽  
Single Feature ◽  
Morphological Differences

Summary There is no single feature to distinguish free-living soil nematodes from freshwater nematodes, also because all free-living nematodes are essentially aquatic. This notwithstanding, by examining the frequencies of some characters of 1141 European species, differences of qualitative/quantitative characters between soil and freshwater nematodes were found. In particular, aquatic and semi-aquatic species are, on average, longer and slimmer than soil species, have a longer tail, greater body weight, smooth cuticle and larger amphids. A new body parameter, length of the pharynx in relation to the length of the whole digestive tract (e), was also taken into consideration.

Free-living freshwater nematodes from Brazil: checklist of genera and regional patterns of diversity

Nematology ◽  
2021 ◽  
pp. 1-14
Author(s):  
Taciana Kramer de Oliveira Pinto ◽  
Sérgio A. Netto ◽  
André Morgado Esteves ◽  
Francisco José Victor de Castro ◽  
Patricia Fernandes Neres ◽  
...  
Keyword(s):  
Benthic Communities ◽  
Extreme Environments ◽  
Freshwater Ecosystems ◽  
Freshwater Biodiversity ◽  
High Turnover ◽  
Free Living ◽  
Regional Patterns ◽  
Freshwater Nematodes ◽  
Spatial Coverage ◽  
Freshwater Habitats

Summary Brazil has one of the largest varieties of aquatic ecosystems and rich freshwater biodiversity, but these components have constantly been damaged by the expansion of unsustainable activities. Free-living nematodes are an abundant and ubiquitous component of continental benthic communities, occurring in all freshwater habitats, including extreme environments. Despite this, hardly any studies have examined the generic composition of nematodes in different latitudes and the geographic overlap of assemblages. We provide data on nematode genera from six regions in Brazil, over a north-south gradient spanning about 4000 km, encompassing rivers, coastal lakes, and reservoirs with different levels of human impact. Interpolation/extrapolation curves were generated and the zeta diversity was used to assess the overlap of nematode assemblages. Freshwater nematode assemblages comprised 54 families and 132 genera. Mononchidae, Monhysteridae, Chromadoridae, Tobrilidae and Dorylaimidae were the most diverse families. Differences in diversity and high turnover of genera were found among regions, probably related to stochastic processes. Mononchus was the only widely distributed genus. Our results revealed a high biodiversity of free-living freshwater nematodes among the regions. The limited spatial coverage of the data reveals an enormous knowledge gap in a country with 12% of the world’s freshwater resources. The lack of spatial patterns, e.g., latitudinal variation, suggests that freshwater nematode assemblages are primarily structured by the intrinsic properties of habitats. This reinforces the uniqueness of freshwater ecosystems and suggests that the nematode assemblages may be sensitive to environmental disturbances, since the limited distributions of taxa may lead to lower resilience.

Revision of the genus Setosella (Bryozoa: Cheilostomata) with description of new species from deep-waters and submarine caves of the Mediterranean Sea

Zootaxa ◽  
2020 ◽  
Vol 4728 (4) ◽  
pp. 401-442 ◽  
Author(s):  
A. ROSSO ◽  
E. DI MARTINO ◽  
V. GEROVASILEIOU
Keyword(s):  
New Species ◽  
Southern Italy ◽  
Free Living ◽  
Deep Waters ◽  
Scanning Electron Microscopy Examination ◽  
Species Complexes ◽  
Morphological Differences ◽  
Three New Species ◽  
Submarine Caves ◽  
Microscopy Examination

The genus Setosella included to date six species. After revision, only four of these species were retained, i.e. S. vulnerata, S. cavernicola, S. folini and S. spiralis. The remaining two species were tentatively placed in Woodipora, W.? antilleana n. comb., and Andreella,  A.? fragilis n. comb. On the other hand, scanning electron microscopy examination of Mediterranean material, revealed the presence of three new species previously included in species complexes: S. cyclopensis n. sp. from the open-shelf, S. rossanae n. sp. from submarine caves, and S. alfioi n. sp. from deep-waters. The diagnosis of the genus was amended to include the occurrence of kenozooids in S. cyclopensis n. sp. and S. cavernicola, and of free-living ring-shaped and scorpioid colonies in S. folini and S. alfioi n. sp. All the seven species n           1ow in Setosella have present-day representatives; the geographic distribution of the genus 1sinian of southern Italy and insular Greece, with only three species occasionally and discontinuously reported. All species are able to produce numerous, subsequent intramural buds and morphological differences seem to be consistently associated with exploitation of particular habitats and substrata. 

Nematophagous fungi in pasture: colonisation of sheep faeces and their potential for control of free-living stages of gastro-intestinal nematode parasites of sheep

2002 ◽  
Vol 42 (1) ◽  
pp. 7 ◽  
Author(s):  
F. S. Hay ◽  
J. H. Niezen ◽  
D. Leathwick ◽  
R. A. Skipp
Keyword(s):  
Laboratory Experiments ◽  
Nematophagous Fungi ◽  
Soil Nematodes ◽  
Arthrobotrys Oligospora ◽  
Free Living ◽  
Intestinal Nematode ◽  
Nematode Parasites ◽  
Fungal Propagules ◽  
Third Stage ◽  
Filter Type

Sheep faeces placed on a pasture in New Zealand in February and April were retrieved at intervals up to 28 days and examined for fungi that parasitise nematodes (nematophagous fungi). Monacrosporium haptotylum, Harposporium bysmatosporum, H. helicoides and a Nematoctonus sp. were present, respectively, in 37, 22, 13 and 8% of 283 samples retrieved in February and from 29, 14, 11 and 15% of 200 samples retrieved in April. Fungi entered faeces rapidly, being present in 35 and 54% of samples retrieved after 3 days in February and April, respectively. The ability of migrating soil nematodes to carry fungal propagules from soil into faeces was assessed in 2 laboratory experiments. Sheep faeces separated from soil by filters that allowed passage of both nematodes and fungi was colonised by H. helicoides more frequently than faeces on filters that excluded nematodes, indicating nematodes were vectors. However, Arthrobotrys oligospora, M. haptotylum and A. brochopaga occurred in faeces independently of filter type, indicating that these species grew into faeces. Two laboratory experiments examined the ability of nematophagous fungi, when inoculated into sheep faeces containing eggs of the gastro-intestinal nematode parasite Trichostrongylus colubriformis to reduce the number that developed to third-stage larvae. Monacrosporium gephyropagum, A. cladodes, A. conoides and A. oligospora reduced the number of third-stage larvae that emerged by 54–91% (P<0.05) in comparison to a control; however, M. haptotylum and H. bysmatosporum were ineffective. In a second experiment, several species of nematophagous fungi reduced the number of third-stage larvae that emerged by 41–96% (P<0.05) in comparison to a control, while others had no effect.

Gyrodactylus derjavinoides sp. nov. (Monogenea, Platyhelminthes) on Salmo trutta trutta L. and G. derjavini Mikailov, 1975 on S. t. caspius Kessler, two different species of Gyrodactylus — combined morphological and molecular investigations

2007 ◽  
Vol 52 (2) ◽  
Author(s):  
Göran Malmberg ◽  
Catherine Collins ◽  
Carey Cunningham ◽  
Behiar Jalali
Keyword(s):  
Phylogenetic Analysis ◽  
New Species ◽  
Molecular Analysis ◽  
Salmo Trutta ◽  
Western Europe ◽  
Species Differences ◽  
Its Rdna ◽  
Intraspecific Variations ◽  
Morphological Differences ◽  
Salmo Trutta Caspius

AbstractThe paper deals with two morphologically similar but molecularly clearly different species of Gyrodactylus: G. derjavinoides sp. nov. on Salmo trutta trutta L. in Western Europe and G. derjavini Mikailov. 1975 collected on Salmo trutta caspius Kessler in Iran. The new species is described and its opisthaptoral hard parts compared to those of G. derjavini. Our molecular analysis of G. derjavinoides and G. derjavini confirmed that the morphological differences between them are species differences and not intraspecific variations. Phylogenetic analysis using the ITS rDNA region placed both species within the subgenus G. (Limnonephrotus) and within the G. wageneri-group, quite in accordance with morphological results. The two species, however, did not cluster as sister taxa. The correspondence between molecular-based clades within G. (Limnonephrotus) and the morphological shapes of marginal hooks within these clades are discussed. The importance of combined molecular and morphological analyses when describing or redescribing Gyrodactylus species is stressed.

scholarly journals Plants with known antagonistic properties against pests: how they influence non-target free-living soil fauna?

2017 ◽  
Vol 15 (4) ◽  
pp. 41-53
Author(s):  
Kassimira Ilieva-Makulec ◽  
Michał Bielecki ◽  
Grzegorz Makulec
Keyword(s):  
Egg Production ◽  
Soil Fauna ◽  
Antagonistic Effect ◽  
Egg Laying ◽  
Soil Nematodes ◽  
Aqueous Extracts ◽  
Direct Effects ◽  
Free Living ◽  
Living Species ◽  
Reproduction Period

The aim of the study was to investigate the effect of three plant species with known antagonistic properties against pests on selected free-living species of soil fauna. The direct effects of aqueous extracts (from hemp leaves and garlic pulp) on the survival of representatives of nematodes, potworms and earthworms were studied. In the case of nematodes, the effects of hemp extracts on the egg production, total fertility and juvenile hatching efficiency were also assessed. Moreover the indirect plant impact (in the form of hemp litter added to the soil or through the root system during planting of castor bean) on soil nematodes was studied. The results of the bioassays confirmed the antagonistic effect of the plant extracts. The most sensitive to the hemp extract toxicity were nematodes, less potworms and at least earthworms. The toxicity of the hemp extract showed a clear dependence on its concentration. The garlic extract showed less toxicity to nematodes than the hemp extract did. The incubation of nematode females in the hemp extracts of different concentrations affected the rate of egg laying, the length of reproduction period and the hatching efficiency but did not affect their overall fertility. In soil, both the hemp litter and the castor plants had a positive indirect effect on the numbers of nematodes at least during the experiment.

scholarly journals Morphology of caterpillars and pupae of European Maculinea species (Lepidoptera: Lycaenidae) with an identification table

2006 ◽  
Vol 17 (4) ◽  
pp. 351-358 ◽  
Author(s):  
Ewa Śliwińska ◽  
Piotr Nowicki ◽  
David Nash ◽  
Magdalena Witek ◽  
Josef Settele ◽  
...  
Keyword(s):  
Species Differences ◽  
The Other ◽  
Larval Instars ◽  
European Species ◽  
Ant Nest ◽  
Effective Conservation

Ofthe four recognized Maculinea species that occur in Europe, three (M. teleius, M. nausitlzous, and M. alcon) are found on damp meadows, and may co-occur; sometimes their larval instars even occupy the same host ant nest. It is, therefore, important to be able to distinguish between the caterpillars of these species for effective conservation. We present the morphology of the larvae and pupae of these three species, and a simple key to their identification. Inter-specific differences among larvae and pupae, and within-species differences among larval instars, are underlined in order to enable their proper identification. The length, colour and distribution of bristles are considered the best features for species and instar identification. The morphology ofthe described species is compared with that of the other European species, M. arion.

scholarly journals Fungi associated with free-living soil nematodes in Turkey

2015 ◽  
Vol 67 (4) ◽  
pp. 1173-1183
Author(s):  
Salih Karabörklü ◽  
Abdurrahman Ayvaz ◽  
Semih Yilmaz ◽  
Ugur Azizoglu
Keyword(s):  
Phylogenetic Trees ◽  
World Wide ◽  
Large Subunit ◽  
Soil Samples ◽  
Soil Types ◽  
Soil Nematodes ◽  
Free Living ◽  
Fungal Strains

Free-living soil nematodes have successfully adapted world-wide to nearly all soil types from the highest to the lowest of elevations. In the current study, nematodes were isolated from soil samples and fungi associated with these free-living soil nematodes were determined. Large subunit (LSU) rDNAs of nematode-associated fungi were amplified and sequenced to construct phylogenetic trees. Nematode-associated fungi were observed in six nematode strains belonging to Acrobeloides, Steinernema and Cephalobus genera in different habitats. Malassezia and Cladosporium fungal strains indicated an association with Acrobeloides and Cephalobus nematodes, while Alternaria strains demonstrated an association with the Steinernema strain. Interactions between fungi and free-living nematodes in soil are discussed. We suggest that nematodes act as vectors for fungi.

Description of the egg and larva of Paederidus Mulsant & Rey, 1878 (Coleoptera, Staphylinidae, Paederinae) based on the two European species

Zootaxa ◽  
2011 ◽  
Vol 2888 (1) ◽  
pp. 39 ◽  
Author(s):  
BERNARD STANIEC ◽  
EWA PIETRYKOWSKA-TUDRUJ ◽  
DOROTA SAŁAPA
Keyword(s):  
Maxillary Palp ◽  
Labial Palp ◽  
Immature Stages ◽  
Body Parts ◽  
Body Colour ◽  
Detailed Structure ◽  
European Species ◽  
Morphological Differences

The egg of Paederidus ruficollis (Fabricius, 1781) and larvae of that and P. rubrothoracicus carpathicola Scheerpeltz, 1957 are described and illustrated. This is the first thorough description of immature stages for the genus Paederidus Mulsant & Rey (1878). The immature stages were obtained by rearing adults. Morphological differences between instars of the same species and also between the studied species are found in the detailed structure of the antenna, nasale, maxillary palp, labial palp, tarsungulus and urogomphus; chaetotaxy of pronotum, profemur and protibia; proportions of same body parts; microstructure of urogomphus and body colour. Comparative characters of larvae of two subtribes Paederina and Stilicina are presented.

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