Checklist of the adult nematode parasites of fishes in freshwater localities from Mexico

Zootaxa ◽  
2006 ◽  
Vol 1201 (1) ◽  
pp. 1 ◽  
Author(s):  
LORENA GARRIDO-OLVERA ◽  
LUIS GARCÍA-PRIETO ◽  
GERARDO PÉREZ-PONCE DE LEÓN

Based on original data gathered from fieldwork during the last years and from previous records from all published accounts, a checklist of the adult nematode parasites of freshwater fishes from Mexico is presented. The checklist is organized as a nematode-host list and comprises taxonomic and geographic distributional information. In total, the checklist includes 70 taxa (50 identified at species level) pertaining to 13 families. These taxa have been collected from 107 freshwater fish taxa in 198 localities along the Mexican Republic. The information we provide herein indicates that sampling effort has been concentrated in Central and South East Mexico, with the Northern region remaining mostly unexplored. The proportion of endemic nematodes is high in the country (74%, i.e., 37 of the 50 taxa identified at species level). The family Rhabdochonidae displays the highest species richness (12 species), and Rhabdochona kidderi is the most widespread nematode species in the country. Cichlids represent the host group with the largest number of samples in Mexico. Finally, we present a list containing new records of larval nematodes from localities in the states of Michoacán, Nayarit, Oaxaca, Tamaulipas and Veracruz.

2021 ◽  
Vol 11 (14) ◽  
pp. 6590
Author(s):  
Krittakom Srijiranon ◽  
Narissara Eiamkanitchat

Air pollution is a major global issue. In Thailand, this issue continues to increase every year, similar to other countries, especially during the dry season in the northern region. In this period, particulate matter with aerodynamic diameters smaller than 10 and 2.5 micrometers, known as PM10 and PM2.5, are important pollutants, most of which exceed the national standard levels, the so-called Thailand air quality index (T-AQI). Therefore, this study created a prediction model to classify T-AQI calculated from both types of PM. The neuro-fuzzy model with a minimum entropy principle model is proposed to transform the original data into new informative features. The processes in this model are able to discover appropriate separation points of the trapezoidal membership function by applying the minimum entropy principle. The membership value of the fuzzy section is then passed to the neural section to create a new data feature, the PM level, for each hour of the day. Finally, as an analytical process to obtain new knowledge, predictive models are created using new data features for better classification results. Various experiments were utilized to find an appropriate structure with high prediction accuracy. The results of the proposed model were favorable for predicting both types of PM up to three hours in advance. The proposed model can help people who are planning short-term outdoor activities.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Peter Halvarsson ◽  
Johan Höglund

Abstract Background A novel way to study the species composition and diversity of nematode parasites in livestock is to perform deep sequencing on composite samples containing a mixture of different species. Herein we describe for the first time the nematode community structures (nemabiomes) inhabiting Swedish sheep and how these are/were affected by host age and recent anthelmintic treatments. Methods A total of 158 fecal samples were collected (n = 35 in 2007 and n = 123 in 2013–2016) and cultured from groups of sheep on 61 commercial farms in the south-central part of the country where most animals are grazed. Among the samples, 2 × 44 (56%) were paired collections from the same groups pre- and post-treatment with anthelmintics such as macrocyclic lactones, benzimidazoles or levamisole. Samples were analyzed for their nemabiome using the PacBio platform followed by bioinformatic sequence analysis with SCATA. Species richness and diversity were calculated and analyzed in R. Results Nematode ITS2 sequences were found in all larval culture samples except two, even though the fecal egg counts were below the McMaster threshold in 20 samples. Sequencing yielded, on average, 1008 sequences per sample. In total, 16 operational taxonomical units (OTU), all with ≥ 98 % identity to sequences in the NCBI database, were recognized. The OTUs found represented nematode species of which ten are commonly associated with sheep. Multiple species were identified in all pre-anthelmintic treatment larval culture samples. No effects on nematode diversity were found in relation to host age. On the other hand, recent anthelmintic treatment lowered species richness, especially after use of ivermectin and albendazole. Interestingly, despite zero egg counts after use of levamisole, these samples still contained nematode DNA and especially H. contortus. Conclusions Our findings provide evidence that nemabiome analysis combined with diversity index analysis provides an objective methodology in the study of the efficacy of anthelmintic treatment as both high and low abundant species were detected.


2009 ◽  
Vol 23 (3) ◽  
pp. 193 ◽  
Author(s):  
Matjaž Kuntner ◽  
Ingi Agnarsson

Phylogenies are underutilised, powerful predictors of traits in unstudied species. We tested phylogenetic predictions of web-related behaviour in Clitaetra Simon, 1889, an Afro-Indian spider genus of the family Nephilidae. Clitaetra is phylogenetically sister to all other nephilids and thus important for understanding ancestral traits. Behavioural information on Clitaetra has been limited to only C. irenae Kuntner, 2006 from South Africa which constructs ladder webs. A resolved species-level phylogeny unambiguously optimised Clitaetra behavioural biology and predicted web traits in five unstudied species and a uniform intrageneric nephilid web biology. We tested these predictions by studying the ecology and web biology of C. perroti Simon, 1894 on Madagascar and C. episinoides Simon, 1889 on Mayotte. We confirm predicted arboricolous web architecture in these species. The expected ontogenetic allometric transition from orbs in juveniles to elongate ladder webs in adults was statistically significant in C. perroti, whereas marginally not significant in C. episinoides. We demonstrate the persistence of the temporary spiral in finished Clitaetra webs. A morphological and behavioural phylogenetic analysis resulted in unchanged topology and persisting unambiguous behavioural synapomorphies. Our results support the homology of Clitaetra hub reinforcement with the nephilid hub-cup. In Clitaetra, behaviour was highly predictable and remained consistent with new observations. Our results confirm that nephilid web biology is evolutionarily conserved within genera.


Nematology ◽  
2004 ◽  
Vol 6 (5) ◽  
pp. 655-669 ◽  
Author(s):  
Iris Michiels ◽  
Walter Traunspurger

AbstractThe meiofauna community in the eutrophic Lake Obersee was investigated, with special emphasis on nematodes, from March 2001 to December 2003. Meiobenthos showed a stable annual and seasonal pattern with oligochaetes contributing most to benthic biomass and nematodes to benthic abundance. With 152 nematode species, Lake Obersee is the most nematode species-rich lentic habitat described so far. The nematode community was dominated by the family Monhysteridae. Bacterial feeders were the most abundant feeding type; omnivorous nematodes contributed most to total nematode biomass. Reproduction occurred throughout the year, with most species reproducing parthenogenetically. No seasonal pattern in reproductive strategies was found.


2012 ◽  
Vol 16 (1) ◽  
pp. 437-448 ◽  
Author(s):  
Carol A. Prescott ◽  
Deanna Lyter Achorn ◽  
Ashley Kaiser ◽  
Lindsey Mitchell ◽  
John J. McArdle ◽  
...  

Project TALENT is a US national longitudinal study of about 377,000 individuals born in 1942–1946, first assessed in 1960. Students in about 1,200 schools participated in a 2-day battery covering aptitudes, abilities, interests, and individual and family characteristics (Flanagan, 1962; www.projectTALENT.org). Follow-up assessments 1, 5, and 11 years later assessed educational and occupational outcomes. The sample includes approximately 92,000 siblings from 40,000 families, including 2,500 twin pairs and 1,200 other siblings of twins. Until recently, almost no behavior genetic research has been conducted with the sample. In the original data collection information was not collected with the intent to link family members. Recently, we developed algorithms using names, addresses, birthdates, and information about family structure to link siblings and identify twins. We are testing several methods to determine zygosity, including use of yearbook photographs. In this paper, we summarize the design and measures in Project TALENT, describe the Twin and Sibling sample, and present our twin-sib-classmate model. In most twin and family designs, the ‘shared environment’ includes factors specific to the family combined with between-family differences associated with macro-level variables such as socioeconomic status. The school-based sampling design used in Project TALENT provides a unique opportunity to partition the shared environment into variation shared by siblings, specific to twins, and associated with school- and community-level factors. The availability of many measured characteristics on the family, schools, and neighborhoods enhances the ability to study the impact of specific factors on behavioral variation.


Author(s):  
J. A. Allen

The survey of the sublittoral fauna of the Clyde Sea Area from 1949 onwards has shown that five species of the Protobranchiata are abundant throughout this region on a variety of substrata. Pelseneer (1891, 1899, 1911), Heath (1937), and Yonge (1939) have contributed much to the knowledge of the group as a whole, but little comparative work has been done at species level. Verrill & Bush (1897, 1898) studied the shell characters of the American Atlantic species. Moore (1931 a, b) worked on the faecal pellets of the British Nuculidae and attempted to distinguish the species by this means, while Winckworth (1930,1931), mainly in the light of the latter work, attempted to clarify the nomenclature of these species. Winckworth (1932) lists six British species of the family Nuculidae: Nucula sulcata Bronn, N. nucleus (Linné), N. hanleyi Winckworth, N. turgida Leckenby & Marshall, N. moorei Winckworth and N. tenuis (Montagu); and four species of the family Nuculanidae: Nuculana minuta (Müller), Yoldiella lucida (Loven), Y. tomlini Winckworth and Phaseolus pusillus (Jeffreys). All species of Nucula, except N. hanleyi, were taken from the Clyde Sea Area, although the latter species is included in the Clyde fauna list (Scott Elliot, Laurie & Murdoch, 1901). Only Nuculana minuta of the Nuculanidae has been taken on the present survey. Yoldiella tomlini is included in the 1901 list but is noted as being ‘insufficiently attested’. Nucula hanleyi was obtained from the Marine Station, Port Erin, but Yoldiella and Phaseolus were unobtainable.


2016 ◽  
Vol 37 (2) ◽  
pp. 729
Author(s):  
Rodrigo Vieira da Silva ◽  
Dalila Sêni de Jesus ◽  
Brenda Ventura de Lima e Silva ◽  
Bruno Eduardo Cardozo de Miranda ◽  
João Pedro Elias Gondim

Miconia albicans (Melastomataceae), whose common name is canela-de-velha, is a native plant of the tropical region that is abundant in the Cerrado biome. A nematode species was found parasitizing M. albicans, causing severe deformation and gall-like structures on the infected leaves and inflorescences. Morphological, morphometric and molecular characterizations identified the nematode as Ditylenchus gallaeformans. This nematode has great potential as a biocontrol agent of plants in the family Melastomataceae, which are invasive weeds in ecosystems of the Pacific Islands. This is the first report of D. gallaeformans parasitizing M. albicans in the Cerrado of the state of Goiás.


2018 ◽  
Vol 63 (4) ◽  
pp. 766-771 ◽  
Author(s):  
Nessrine Ghanmi ◽  
David González-Solís ◽  
Lamia Gargouri

Abstract Helminthological examinations of the red mullet Mullus barbatus (Linnaeus) (Mullidae) from the Gulf of Hammamet, off Tunisia, revealed the presence of one undescribed gonad-infecting nematode species, Philometra barbata n. sp. (Philometridae). The new species as other congeneric species is mainly characterized by the shape of the caudal mound, the distribution of the caudal papillae and the shape of the gubernaculum with the presence of a dorsal protuberance consisting of two dorsolateral lamellar parts separated from each other by a smooth median field in the male. The new species differs from its gonadinfecting congeners in the body length of male, the length of spicules and gubernaculum. This is the second nominal species of Philometra reported from fishes of the family Mullidae and the 14th from the Mediterranean Sea.


Karstenia ◽  
2021 ◽  
pp. 1-12
Author(s):  
Carlos Rojas ◽  
Pedro A. Rojas ◽  
Steven L. Stephenson

Long-term monitoring and phenological patterns of microbial communities are rare in the scientific literature. Myxomycetes have life cycle characteristics that allow both to be documented. The present study summarizes the integrated floristic and bioclimatic components of a 30-month assessment of myxomycete sporocarps in a premontane tropical forest in Turrialba, Costa Rica. Based on monthly visits and a standard sampling effort of 120 minutes per visit, myxomycetes were recorded on leaves, twigs, and logs on the ground by two to three people in 20-minute periods associated with six different collecting sites within a 34-hectare successional forest patch. Biological data were analyzed using three recorded climatic variables obtained <em>in situ</em> during the complete period of study. Also, the Oceanic Niño Index (ONI), provided by NOAA, an estimate of El Niño-Southern Oscillation (ENSO), was evaluated in the analyses. Overall, 54 species and 2245 records of myxomycetes were recorded, with an average of 14.5 species (range between 6-24) and 78.4 records (range between 20-110) detected each month. In general, neither the number of records nor the number of species were associated with individual climate variables, but multiple regression analyses showed that a combination of the accumulated precipitation of the four days before sampling and the average relative humidity can explain most of the fruiting dynamics (R2 = 0.56). When the ONI index was included in the analyses, the explained variability increased (R2 = 0.64), and when a categorization of months based on the same index was used, analyses showed that both the number of records and species evenness were affected by ENSO. At the species level, <em>Hemitrichia calyculata</em> was the only species observed during every month, closely followed by <em>Arcyria cinerea</em>, <em>A. denudata</em>, and <em>Physarum compressum</em>, recorded on most visits. Sporadic fruiting in some species such as <em>Tubifera microsperma</em>, <em>P. tenerum</em>, <em>P. bogoriense</em>, <em>P. melleum</em>, and <em>Metatrichia vesparia</em> could have been associated with local climate oscillations influenced by ENSO patterns. Phenological patterns were observed at the species level, indicating that in the Neotropics, under favorable conditions, myxomycete sporocarps are practically always present, but species assemblages vary temporally. These variations are primarily driven by local climate, but regional climate dynamics also affect fruiting patterns. Presumably, the remaining ecological effect on fruiting patterns in the Neotropics can be attributed to certain finer factors such as ecosystem structure, substrate quality/ availability, and biotic interactions. As such, phenomena such as climate change can have an important effect on the production of sporocarps by tropical myxomycetes, with subsequent effects of their ecological dynamics.


Author(s):  
Pavlína Šenoldová ◽  
Jiří Rotrekl

This paper compares efficiency of preparations based on a parasitic nematode species Phasmarhabditis hermaphrodita with a molluscocide containing methiocarb as an effective substance. Parasitic nematodes by the family Agriolimacidae showed a significantly better effect on mortality and reduction of the percentage of damaged plants than the methiocarb-based preparation. Under laboratory and field conditions, the efficiency of parasitic nematodes on the family Agriolimacidae ranged from 84% to 94% and from 81% to 94%, resp., while the percentages of damaged plants were minimal in both cases. The corresponding effects of the methiocarb-based molluscocide were only 35% and 21%, resp. The effect of parasitic P. hermaphrodita nematodes on members of the snail family Arionidae was not demonstrated both under laboratory and field conditons and the mortality was up to 6% with a total defoliation of plants. Under laboratory and field conditions, the mortality of slugs from the genus Arion after the application of methiocarb-based preparation was 53% and 38%, resp. However, the damage of plants was significant and it reached nearly 67% and 60% under laboratory and field conditions, resp.


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