Bitylenchus hispaniensis, Handoo & Palomares-Rius & Cantalapiedra-Navarrete & Liébanas & Subbotin & Castillo, 2014

Handoo, Zafar A., Palomares-Rius, Juan E., Cantalapiedra-Navarrete, Carolina, Liébanas, Gracia, Subbotin, Sergei A. & Castillo, Pablo, 2014, Integrative taxonomy of the stunt nematodes of the genera Bitylenchus and Tylenchorhynchus (Nematoda, Telotylenchidae) with description of two new species and a molecular phylogeny, Zoological Journal of the Linnean Society 172 (2), pp. 231-264 : 236

BITYLENCHUS HISPANIENSIS SP. NOV.

( FIGS 1–3 , TABLES 2–3)

Holotype: Female extracted from soil samples collect- ed from the rhizosphere of wild olive ( Olea europaea ssp. silvestris ), in Córdoba, Córdoba province , Spain, by P. Castillo, mounted in pure glycerine, and deposited in the USDA Nematode collection, Beltsville, Maryland (collection number T- 416t).

Paratypes: Female paratypes extracted from soil samples collected from the rhizosphere of wild olive ( Olea europaea ssp. silvestris ), in Córdoba , Córdoba province , Spain, were deposited in the following nematode collections: the USDA Nematode collection, Beltsville , Maryland (collection numbers T-6233p to T-6248p); and the Nematode collection of the Department of Nematology , Landbouwhogeschool, Wageningen, the Netherlands (collection number OL32-4) .

Etymology: The specific epithet refers to the geographical origin and is derived from the Latin hispaniensis = Spanish, from Spain.

Description of female: Body arcuate to open C shape after heat fixation, no longitudinal striae or ridges outside lateral fields. Body annuli distinct but fine, 1.0– 1.5 μm wide around mid-body. Lateral fields originating at the level of the conus of the stylet and extending up to hyaline region of tail to tail terminus, with four incisures, outer two incisures areolated. Lip region high, rounded, almost continuous to body contour, 7.2 ± 0.3 (6.5–7.5) μm wide, 3.6 ± 0.3 (3.0–4.0) μm wide; with five to seven annuli. SEM observations show labial plate slightly squarish in outline, fused with labial sectors, bordering the amphidial apertures, small rounded labial disc and an oval oral opening surrounded by six labial papillae, labial disc with six raised papillae or prongs/ lips ( Fig. 3A, B ). Stylet moderately strong, shaft and conus equally long; knobs laterally to posteriorly directed. Dorsal gland orifice about 2.5 μm long behind stylet base. Median pharyngeal bulb oblong, basal bulb pyriform. Cardia well developed. Nerve ring located at 83.1 ± 5.6 (73.0–95.0) μm from anterior end. Hemizonid usually just two to three annuli anterior to excretory pore, 1.0–1.5 annuli wide. Lateral canals (intestinal fasciculi) present in the intestinal region, often extending to the tail terminus. Vulva a transverse slit slightly posterior to the middle of the body and distinctly protruding. Epiptygma absent. Reproductive system amphidelphic, didelphic; anterior and posterior ovaries equally developed. Spermatheca rounded, filled with rounded spermatozoa. Tail bluntly rounded hemispherical to clavate, tail terminus annulated. Phasmids located slightly anterior to middle of the tail. Postanal extension of intestine absent.

Description of male: Abundant, morphologically similar to female except for sexual characters, and body in posterior region usually more curved than in female. Gubernaculum well developed, half of the spicule length. Tail terminus conoid-pointed, bursa extending to the tail terminus.

Diagnosis: Bitylenchus hispaniensis sp. nov. is characterized by a median body length (548–790 μm), a high, rounded, almost continuous lip region with five to seven annuli, stylet moderately strong, 15.5–18.5 μm long with laterally to posteriorly directed knobs, lateral fields with four incisures, outer two crenate, lateral canals (intestinal fasciculi) present in the intestinal region, tail bluntly rounded with a hemispherical to clavate terminus, phasmids located slightly anterior to middle of the tail, and postanal extension of intestine absent. Specific D 2–D3, ITS, and 18S rRNA sequences were deposited in GenBank with accession numbers KJ461544 – KJ461548 , KJ461576 – KJ461578 , and KJ461608 – KJ461609 , respectively .

Figures

Figure 1. Line drawings of Bitylenchus hispaniensis sp. nov. A, female pharyngeal region; B, vulval region showing part of gonads and spermatheca; C, female lip region; D, details of lip region showing oral disc (en face view); E, F, male tails showing spicules and gubernaculum; G–J, female tails, with H and I showing intestinal fasciculi/sinuous canals present and extending back to tail, and J with areolated lateral fields and phasmid in the middle.

Figure 2. Photomicrographs of Bitylenchus hispaniensis sp. nov. A, whole body of female and male; B, female pharyngeal region; C, female lip region; D, vulval region; E, female tails; F, male tail; G, lateral fields at mid-body. Scale bars: A = 50 μm, B, E = 10 μm; C, D, G = 5 μm; F = 20 μm.

Figure 3. Scanning electron microscope photographs of Bitylenchus hispaniensis sp. nov. A, female lip region; B, en face view showing oral (oa) and amphidial (am) apertures; C, lateral fields at mid-body; D, E, female tails showing anus (a) and phasmid (ph); F, male tail showing spicules (sp). Scale bars: A, C = 10 μm; B = 5 μm; D–F = 20 μm.