Variabilité intraspecifique et intragenérique des structures cuticulaires externes dans le genre Aorolaimus Sher, 1963 (Nemata: Hoplolaimidae)
Seven species in the genus Aorolaimus are studied with the stereoscan electron microscope: A. helicus, A. leiomerus, A. luci, A. macbethi, A. striatus, A. longistylus and A. perscitus. The results show that many characteristic cuticular features (form of the head, head constriction, prominence of labial disc, presence and number of longitudinal striations on basal lip annule, tail form, form of tail annules, presence of epiptygma, indentation of the bursa) are variable at specific level and cannot be used for specific characterization. Some other characters (number of lip annules, presence of areolations at phasmid level in lateral fields, ornamentation of lateral fields) show a low variability, are relatively constant in the genus, have limited use as identification criteria at the specific level, and help to separate species into groups. Study of the morphology of the epiptygma shows that this organ has a tubular structure which can be retracted and/or coiled into the vagina or protruded from the vulva to varying degrees, appearing in lateral optical section single when flattened or double when the tube is open. The synonymy of Peltamigratus and Nectopelta with Aorolaimus is confirmed. Eight new combinations are proposed: A. areolatus, A. levicaudatus, A. amazonensis, A. cerradoensis, A. raskii, A. paraensis, A. vigiae, A. banoae for species originally in Peltamigratus. A. intermedius is transferred to the genus Hoplolaimus as Hoplolaimus intermedius n. comb. The 32 species of the genus are placed in three groups according to (i) phasmid position, (ii) the presence of areolations at phasmid level in the lateral field, and (iii) the type of longitudinal ornamentations in the lateral fields. Morphological differences between the genera Scutellonema and Aorolaimus are discussed.
| Main Authors: | , , , , , |
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| Format: | artículo biblioteca |
| Language: | English |
| Published: |
Springer
1991
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| Online Access: | http://hdl.handle.net/10261/12050 |
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