Free-Living and Plant-Parasitic Nematodes From Venezuela

Loof, P.A.A.

doi:10.1163/187529264x00042

Cited by 67 publications

(43 citation statements)

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“…Five species had sizable and consistent populations (Tables 1, 2): Chronogaster floridensis (Raski and Maggenti 1984), C. daoi (Loof 1964), C. cf. parva (Heyns and Coomans 1983), C. cf.…”

Section: Resultsmentioning

confidence: 99%

On spatiotemporal patchiness and the coexistence of five species of Chronogaster (Nematoda: Chronogasteridae) in a riparian wetland

2000

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Spatiotemporal patchiness in the soil environment is thought to be crucial for the maintenance of soil biodiversity. It provides diverse microhabitats (allowing resource partitioning), and presents these in a complex mosaic, such that competitors may be spatially and temporally separated (promoting patch dynamics). The objective of our study was to assess the importance of patch dynamics for the maintenance of landscape-level nematode diversity. The spatiotemporal aggregation patterns in populations of five species of the bacterivorous genus Chronogaster were analyzed for a 0.7-ha riparian wetland, during four seasons, using geostatistical methods (spatiotemporal variograms, cross-correlograms, and log-normal kriging). We found that for the three most abundant species, aggregation was significant over distances of 13-39 m, with intraspecific aggregation stronger than interspecific aggregation. In addition, species patterns appeared to be temporally dynamic: local population declines alternated with local blooms at different sites and seasons. One species was consistently present at the same few sites, but the other species showed gradual temporal decreases and increases at different locations in the wetland. Combining nematode patterns with information on soil resource distributions and Chronogaster ecology, indicated that both soil resource patchiness and repeated, but largely unpredictable, disturbances caused by local soil moisture fluctuations could promote landscape-level Chronogaster diversity by providing ample 'probability refuges.' Local species populations, reduced by competition, predation and drought, could recolonize patches either through the awakening of local dormant 'seed populations,' or through limited passive dispersal by wind, water, and phoresis. We suggest that the spatiotemporal Chronogaster data provide preliminary evidence for the importance of patch dynamics in maintaining soil nematode diversity.

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“…Five species had sizable and consistent populations (Tables 1, 2): Chronogaster floridensis (Raski and Maggenti 1984), C. daoi (Loof 1964), C. cf. parva (Heyns and Coomans 1983), C. cf.…”

Section: Resultsmentioning

confidence: 99%

On spatiotemporal patchiness and the coexistence of five species of Chronogaster (Nematoda: Chronogasteridae) in a riparian wetland

2000

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“…The specimens were found in a soil at a depth of 5-15 cm, where the most common plant was tufted hair grass (Deschampsia Loof, 1971, H. tunisiensis Siddiqi, 1963, H. canadensis Waseem, 1961, H. goldeni Sultan & Jairajpuri, 1979, H. vulgaris Yuen, 1964and H. varicaudatus Yuen, 1964 Differences are: H. rohtangus has a longer spear (36-38/xm) and H. spitsbergensis a shorter spear (26-31/xm); H. tuniensis has a trapezoid lip region with concave sides; H. canadensis has a shorter body (L = 0.58--0.93 mm) a smaller oesophageal gland lobe, a slightly shorter spear (28-33/zm) and different shaped tail; H. goldeni has a hemispherical lip region, males and a spermatheca with sperm; H. vulgaris has a higher lip region, shorter tail (8-15/~m long, c = 63-116) with finer annules at distal end; H. varicaudatus has a shorter body (L = 0.58-0.69), and hemispherical lip region and shorter tail (12-17 ~m long, c always less than 1). …”

Section: Descriptionmentioning

confidence: 99%

Helicotylenchus scoticus n.sp. and a conspectus of the genus Helicotylenchus Steiner, 1945 (Tylenchida: Nematoda)

Boag¹,

Jairajpuri

1985

Syst Parasitol

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Helicotylenchus scoticus n. sp. is described. It was found at an altitude of 660 m on the north-west slope of Sgurr Cos na Breachd-laoidh, Scotland, in a rough grassland consisting predominantly of tufted hair grass (Deschampsia caespitosa). This species is characterized by a relatively long spear and an oesophagus which superficially appears to abut on to the intestine with virtually no overlap. The number of nominal species in the genus Helicotylenchus has increased considerably over recent years and stands now at 154 species. The task of identifying species in this genus using dichotomous keys has become increasingly more difficult. As a practical alternative a compendium is given which uses nine of the most diagnostic characters.

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“…Coomansus venezolanus (Loof, 1964) Jairajpuri & Khan, 1977 was originally described as Mononchus venezolanus (Mononchidae) by Loof (1964) 4 from only one female collected together with a juvenile from soil around roots of garlic at 1500-1800 m altitude, from El Jarillo, Venezuela. The main characters were: (i) a strong massive dorsal tooth with its tip located in the anterior third of the buccal cavity; and (ii) absence of 'ventral' ridge in the buccal cavity.…”

Section: Introductionmentioning

confidence: 99%

“…The main characters were: (i) a strong massive dorsal tooth with its tip located in the anterior third of the buccal cavity; and (ii) absence of 'ventral' ridge in the buccal cavity. Jairajpuri & Khan (1977) 2 proposed the new genus Coomansus Jairajpuri & Khan, 1977 (Mononchidae), based on the following main characters: (i) lip and labial papillae well developed; (ii) the absence of the ventral ridge in the buccal cavity, and transferred two species of Mononchus, M. campbelli Allgen, 1929 and M. venezolanus Loof, 1964, to the new genus Coomansus. Jairajpuri & Khan, 1982 recorded Coomansus venezolanus from Himachal Pradesh, India based on a female with a slightly slenderer body than in the holotype 3.…”

Section: Introductionmentioning

confidence: 99%

“…

ABSTRACT: Coomansus venezolanus (Loof, 1964) Jairajpuri & Khan, 1977 from Cao Loc, Lang Son province is described and illustrated and represents a new record for Vietnam. The species is characterized by its body size, 1.9-2.1 mm long, a strongly sclerotized buccal cavity with apex of dorsal tooth situated at 26-30% of buccal cavity length from anterior end and vulva at 60-64% of body length from anterior end.

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confidence: 99%

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New record of Coomansus venezolanus (Loof, 1964) Jairajpuri & Khan, 1977 (Mononchida: Mononchidae) for Vietnam with first description of a male

Tam¹

2016

V J Bio

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Coomansus venezolanus (Loof, 1964) Jairajpuri & Khan, 1977 from Cao Loc, Lang Son province is described and illustrated and represents a new record for Vietnam. The species is characterized by its body size, 1.9-2.1 mm long, a strongly sclerotized buccal cavity with apex of dorsal tooth situated at 26-30% of buccal cavity length from anterior end and vulva at 60-64% of body length from anterior end. A single male specimen is reported for the first time and is characterized by having fifteen spaced ventromedian precloacal supplements, a 74 m long spicule; well developed lateral accessory pieces, 12.5 m long and a weakly developed gubernaculum, 11.4 m long. Measurements and description of the Vietnamese female specimens fit well the holotype, except for a slightly slenderer body (a = 27-31 vs 21) and shorter tail (c = 20-28 vs 18); they also agree with the specimen from Himachal Pradesh, India apart from a slightly shorter tail and a slightly stouter body.

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Free-Living and Plant-Parasitic Nematodes From Venezuela

Cited by 67 publications

References 0 publications

On spatiotemporal patchiness and the coexistence of five species of Chronogaster (Nematoda: Chronogasteridae) in a riparian wetland

On spatiotemporal patchiness and the coexistence of five species of Chronogaster (Nematoda: Chronogasteridae) in a riparian wetland

Helicotylenchus scoticus n.sp. and a conspectus of the genus Helicotylenchus Steiner, 1945 (Tylenchida: Nematoda)

New record of Coomansus venezolanus (Loof, 1964) Jairajpuri & Khan, 1977 (Mononchida: Mononchidae) for Vietnam with first description of a male

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