Rotylenchus, Wimbii, 2021

Singh, Phougeishangbam Rolish, Karssen, Gerrit, Gitau, Kelvin, Wanjau, Cecilia, Couvreur, Marjolein, Pili, Njira Njira, Gheysen, Godelieve & Bert, Wim, 2021, Rotylenchus wimbii n. sp. (Nematoda: Hoplolaimidae) associated with finger millet in Kenya, Journal of Nematology 53 (1), pp. 1-14 : 3-6

publication ID	https://doi.org/ 10.21307/jofnem-2021-016
persistent identifier	https://treatment.plazi.org/id/6B3987EB-FFF2-FFF6-22D7-9EC1FE3100FA
treatment provided by	Felipe
scientific name	Rotylenchus
status	n. sp.

Treatment

ROtylenChUS Wimbii View in CoL n. sp.

Figures 1 View Figure 1 and 2 View Figure 2 , Tables 1 and 2.

Description

Female

Body moderately large (0.6-0.8mm), habitus spiral to 6-shaped when heat relaxed. Lateral field differentiation starting as single areolated band, gradually forming two areolated bands up to level of metacorpus valve and further continuing as three areolated bands up to isthmus level, after which bands becomes smooth till tail terminus. Longitudinal cuticular striations in anterior region absent. Labial region hemispherical with 4 annuli, not offset from body but appears to have a slight depression under LM. En faCe showing rounded labial disc, marked from rest of labial region, not elevated, slit like oral aperture, lateral sectors with two amphidial apertures and smaller than subdorsal and subventral sectors. Basal lip annule with 2 to 3 longitudinal striations (from six face views) forming 3 to 4 irregular blocks, but in one specimen with five striations forming six irregular blocks. Stylet robust with large, rounded, and sometimes indented knobs. Dorsal pharyngeal gland opening at 4 to 6µm from stylet base. Pharynx with well-developed median bulb, valves, slender isthmus, and gland overlapping intestine by maximum 30 µm dorsally. Secretory-excretory pore often at level of pharyngo-intestinal junction. Hemizonid distinct, just above secretory-excretory pore, about two body annuli long. Reproductive tract didelphic-amphidelphic, each branch equally developed with outstretched ovaries containing rows of developing eggs, vulva at 55 to 60% of body length from anterior end, without distinct epiptygma. Spermatheca indistinct to rounded, not filled. Tail very short with commonly truncated tip or sometimes slightly hemispherical to rounded tip. Phasmid pore like, 7 to 17 annuli anterior to anus .

Male

Not found.

Diagnosis and relationships

ROtylenChUS Wimbii n. sp. is characterized by a moderate body size of 0.6 to 0.8 mm, a hemispherical, continuous lip region with four annuli, basal lip annule with 3 to 4 irregular blocks, absence of longitudinal cuticular striations at anterior region, lateral field with four lines forming three equal bands which are areolated around pharynx level, a robust stylet of less than 30µm of which 45 to 53% is cone and with rounded to sometimes indented knobs, didelphic-amphidelphic reproductive system, vulva without distinct epiptygma, indistinct to empty spermatheca, very short truncated tail with 5 to 9 annuli, and pore like phasmids located at 7 to 17 annuli anterior to anus. According to Castillo and Vovlas (2005), the matrix code of this species is A4, B1, C1, D4, E1, F2, G3, H (commonly truncated), I2, J2, K1.

This new species is morphologically closest to ROtylenChUS abnOrmeCaUdatUS Van den Berg and Heyns, 1974 and ROtylenChUS breViCaUdatUS Colbran, 1962 . The females of these three species have similar body sizes, lip region of more or less hemispherical to rounded and very slightly offset to continuous with 4 to 5 annuli, stylet length below 30µm, lateral field areolation only at pharynx level, absence of longitudinal cuticular striations, vulva position of 52 to 62% of body length from anterior end, phasmids positioned at 7 to 17 annuli anterior to anus, and short tail with only 5 to 11 tail annuli. The new species differs from R. abnOrmeCaUdatUS in having 4 vs 4 to 5 lip annuli, a slightly longer cone part of stylet (45-53% vs 42-45%), and often truncated vs irregularly rounded tail terminus. ROtylenChUS abnOrmeCaUdatUS has also been reported with a peculiar and irregular arrangement of annuli and lateral field ending in the posterior part of tail which is not seen in other species including R. Wimbii n. sp. While males of R. Wimbii n. sp. and R. abnOrmeCaUdatUS are not known and subsequently, no sperm is observed in the female spermathecae, males of R. breViCaUdatUS have been reported and the female spermatheca are often filled with sperm. ROtylenChUS Wimbii n. sp. further differs from R. breViCaUdatUS by the presence of 2 to 3 longitudinal striations on the basal lip annule vs 6 to 12 such longitudinal striations as reported by Sher (1965) from the study of six face views of the 20 female topotypes supplied by R.C. Colbran, and commonly truncated vs hemispherical tail terminus. Information on the number of longitudinal striations on basal lip annule for R. abnOrmeCaUdatUS is not available.