Aphelenchoides spicomucronatus Truskova, 1973

Girgan, Chantelle, Swart, Antoinette, Marais, Mariette & Fourie, Hendrika, 2018, Aphelenchoides spp. (Nematoda: Aphelenchida) and Panagrolaimus leperisini (Nematoda: Rhabditida) found associated with grass seeds in the Telperion Nature Reserve, South Africa, Zootaxa 4370 (2), pp. 137-155 : 146-149

publication ID

https://doi.org/ 10.11646/zootaxa.4370.2.3

publication LSID

lsid:zoobank.org:pub:307E8947-81F4-4271-A02A-1115892BEC9C

DOI

https://doi.org/10.5281/zenodo.5970548

persistent identifier

https://treatment.plazi.org/id/03BCA226-FFC9-7512-0ADB-FB8346145A7F

treatment provided by

Plazi

scientific name

Aphelenchoides spicomucronatus Truskova, 1973
status

 

Aphelenchoides spicomucronatus Truskova, 1973

( Fig. 5 View FIGURE 5 & 6 View FIGURE 6 )

Aphelenchoides spicomucronatus was first described from the roots of Glycine hispida (Moench) Maxim. ( Truskova, 1973) View in CoL . However, only three females were examined in describing the species. It was reported for the second time by Rashid et al. (1986) from soil samples collected in Brazil. To date these are the only reports of this species.

Measurements. See table 4.

Description. Female (n = 1): Body slender, habitus slightly curved ventrally. Cuticle finely annulated, annule width approximately 1 µm at mid-body. Lateral field marked with four incisures ( Fig. 5B View FIGURE 5 ). Head slightly offset. Lip region flattened anteriorly ( Fig. 5A View FIGURE 5 ) 3 µm high and 6 µm broad. Stylet 11 µm long with distinct basal swellings. Median bulb spherical in shape with prominent centrally located valves ( Fig. 5A View FIGURE 5 ). Nerve ring situated 74 µm from anterior end, less than one corresponding body width from base of median bulb. Excretory pore 85 µm from anterior end, opposite posterior end of nerve ring ( Fig. 5A View FIGURE 5 ). Ovary outstretched with oocytes arranged in a single row ( Fig. 5D View FIGURE 5 & 6A View FIGURE 6 ). Spermatheca containing spherical sperm cells ( Fig. 6B View FIGURE 6 ). Sperm cells also observed in uterus ( Fig. 6B View FIGURE 6 ). Vulval lips slightly protruding with the vagina occupying less than half the corresponding body width, curving anteriorly. Post-vulval uterine sac 57 µm in length, about three times vulval body width and shorter than half vulva-anus distance ( Fig. 5E View FIGURE 5 & 6D View FIGURE 6 ). Tail conical, 40 µm long with a centrally located mucro ( Fig. 5C View FIGURE 5 & 6C View FIGURE 6 ). Anus distinct, with the anterior lip protruding slightly.

Male: Not found.

Discussion. The female Aphelenchoides specimen recovered from Eragrostis gummiflua samples was identified as A. spicomucronatus based on the characteristic tail mucro shape and presence of four lateral field incisures. Measurements and morphological details match those of Truskova (1973) and Rashid et al. (1986). This specimen differs only in having the excretory pore situated opposite the posterior end of the nerve ring. In both published accounts of A. spicomucronatus , the excretory pore is situated between the median bulb and the nerve ring. However, Rashid et al. (1986) did state that the excretory pore position varied from opposite the median bulb to one median bulb length posterior to it.

Other discrepancies were noted in the above-mentioned descriptions. In Rashid et al. (1986) the spermathecae of 19 females were reported to be empty. However, the original description by Truskova (1973) indicated that sperm cells were observed in the spermatheca and PUS, in all three specimens studied. Sperm cells were seen in the spermatheca of our Telperion specimen. In the original description, the lateral field was described as not visible, but Rashid et al. (1986) observed four incisures in the lateral field in cross sections. Our South African specimen has a lateral field with four incisures. This species is reported for the first time from South Africa. The specimen (accession number 50544) was deposited in the NCN.

Relationships. The Aphelenchoides specimen from Telperion was compared to those species with a tail with one (or sometimes two) terminal mucronate structures and four incisures in the lateral field ( Shahina 1996). Aphelenchoides haguei Maslen, 1979 and A. tuzeti B’Chir, 1979 both have longer stylets - 13 µm and 14 µm, respectively - compared to 11 µm in A. spicomucronatus . The following species have a slightly more posterior vulva position (vs. 69% in the South African species): A. absari Husain & Khan, 1967 (69–77%), A. brassicae Edward & Misra, 1969 (68–74%), A. cyrtus Paesler, 1959 (70–73%), and A. echinocaudatus Haque, 1968 (72%). A. parasaprophilus Sanwal, 1965 (680–750 µm), and A. subtenius ( Cobb, 1926) Steiner & Buhrer, 1932 (870–1150 µm) are larger (L = 669 µm for A. spicomucronatus ) and can also be differentiated by tail shape. A. eradicitus Eroshenko, 1968 (300–310 µm), A. parabicaudatus Shavrov, 1967 (310-350 µm), and A. platycephalus Eroshenko, 1968 (240-270 µm) are much smaller species. A. eradicitus also has a shorter stylet (10 µm compared to 11 µm in A. spicomucronatus ) and more anterior vulva (V = 64% vs. 69%). A. parabicaudatus can be differentiated by its shorter stylet (8 µm vs. 11 µm) and bifurcate tail tip. Aphelenchoides platycephalus has a more anterior nerve ring and a longer mucro.

Aphelenchoides richardsoni Grewal, Siddiqi & Atkey, 1992 View in CoL is the most morphologically similar species in having more developed stylet knobs than the South African specimens. Other closely related species based on morphology are A. daubichaensis Eroshenko, 1968 , and A. tsalolikhini Ryss, 1993 . A. daubichaensis differs in tail shape, with a more centrally located terminal mucro and a shorter tail length (29–31 µm compared to 40 µm in A. spicomucronatus ). Aphelenchoides tsalolikhini also has a longer tail (c’ = 4.6–6.2 compared to 3.3 in A. spicomucronatus ), and different tail shape (long, thorn-like, ventrally situated mucro).

Kingdom

Animalia

Phylum

Nematoda

Class

Chromadorea

Order

Rhabditida

Family

Aphelenchoididae

Genus

Aphelenchoides

Loc

Aphelenchoides spicomucronatus Truskova, 1973

Girgan, Chantelle, Swart, Antoinette, Marais, Mariette & Fourie, Hendrika 2018
2018
Loc

A. tsalolikhini

Ryss 1993
1993
Loc

Aphelenchoides tsalolikhini

Ryss 1993
1993
Loc

Aphelenchoides richardsoni

Grewal, Siddiqi & Atkey 1992
1992
Loc

Aphelenchoides spicomucronatus

Truskova 1973
1973
Loc

Glycine hispida (Moench) Maxim. ( Truskova, 1973 )

(Moench) Maxim. (Truskova 1973
1973
Loc

A. spicomucronatus

Truskova 1973
1973
Loc

A. spicomucronatus

Truskova 1973
1973
Loc

A. daubichaensis

Eroshenko 1968
1968
Loc

A. daubichaensis

Eroshenko 1968
1968
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