Paratrichodorus uliaensis, Decraemer & Archidona-Yuste & Clavero-Camacho & Vovlas & Cantalapiedra-Navarrete & Alba & Ruiz-Cuenca & Castillo & Juan & Palomares-Rius, 2024

Decraemer, Wilfrida, Archidona-Yuste, Antonio, Clavero-Camacho, Ilenia, Vovlas, Alessio, Cantalapiedra-Navarrete, Carolina, Alba, Ruiz-Cuenca, Castillo, Pablo, Juan & Palomares-Rius, 2024, Unravelling cryptic diversity in the Paratrichodorus allius- group species complex to resolve eight new species of the genus and new insights on the molecular phylogeny % Nematoda: Trichodoridae), Zoological Journal of the Linnean Society 202 (3), pp. 1-44 : 5-10

Paratrichodorus uliaensis sp. nov. Decraemer et al.

( Figs 1–3A, B ; Table 2 )

Zoobank registration: urn:lsid:zoobank.org:act:7908CD13-BD88-45CE-BDEA-F24425B2590D

Type material: Holotype. Male extracted from soil samples collected from the rhizosphere of grapevine ( Vitis vinifera ) at Montemayor, Córdoba province, southern Spain (37°38 ʹ 11.7 ʹʹ N latitude, 004°42 ʹ 21.9 ʹʹ W longitude) by J. Martín Barbarroja and G. León Ropero, mounted in pure glycerine and deposited in the nematode collection of Ghent University, Ghent, Belgium (slide number UGMD 104445 ).

Paratypes: Male and female paratypes extracted from soil samples collected from the rhizosphere of grapevine at Montemayor, Córdoba province , southern Spain, were deposited in the following nematode collections: Ghent University, Ghent, Belgium (slide numbers males and females paratype UGMD 104445 - UGMD 104449 ) and one male and one female paratypes at the USDA Nematode Collection, Beltsville, MD, USA (collection number T-8015p ).

Additional material examined: An additional population was collected also in grapevine at La Rambla, Córdoba province , Spain (37°37 ʹ 17.9 ʹʹ N latitude, 4°42 ʹ 13.3 ʹʹ W longitude).

Etymology: The species epithet refers to the roman name (Ulia) of Montemayor, the type locality where the type specimens were collected.

Description of male: Body more or less straight, cigar-shaped, often with swollen cuticle (3.5–7.5 µm at midbody) upon fixation and anteriorly slightly tapered to a rounded lip region appearing offset by the protruding double papillae (four cephalic and two subdorsal and two subventral outer labial papillae). Onchiostyle rather small (average 33.5 µm long). Pharynx at posterior isthmus either gradually widening to a posterior bulb or bulb more or less marked, usually with a pronounced (8–37 µm) ventral overlap of the ventrosublateral pharyngeal glands, rarely a combination of a short dorsal intestinal and a ventral pharyngeal overlap; posterior ventrosublateral gland nuclei close to pharyngo-intestinal junction. Nerve ring surrounding isthmus; secretory-excretory pore (SE-pore) at level of anterior pharyngeal bulb when pharynx relaxed. A single ventromedian CP at rather a short distance (10–22 µm) anterior to SE-pore. Reproductive system monorchic, testis with short germinal zone (25 µm in holotype), and sperm with small oval-shaped nucleus (2.5 × 1.5 µm), closely packed with fibrillar appearance. Spicules medium-sized (average 44.5 µm), nearly straight, with marked capitulum, blade largely equally wide, but distally tapered, transversely striated, except at extremities. Copulatory muscles hardly developed; capsule of suspensor muscles very thin, around anterior half of spicule; gubernaculum with thickened distal part, parallel to spicules. Bursa narrow, rather short, extending from head of retracted spicule to subterminally on tail. Three precloacal supplements, posterior two (SP1 and SP2) opposite distal half of the retracted spicules with SP1 at about equal distance from cloacal opening and from SP2; SP3 little developed and non-protruding, located about 2.5 spicule lengths from the cloacal opening. A pair of well-developed postcloacal supplements close to the cloacal opening, the latter with a small protruding anterior lip flap (in ventral view visible as two flaps bordering the opening). Tail short, less than one anal body diameter long and rounded conical. A pair of caudal pores subterminally near tail tip; cuticle slightly thicker at tail tip (average 3.5 µm).

Description of female: Body slightly ventrally curved; largely similar to male apart from reproductive system and male secondary features. Digestive system with obvious ventral overlap of pharyngeal glands (15–53 µm). SE-pore at posterior level of isthmus or anterior end of pharyngeal bulb. Reproductive system didelphic-amphidelphic with both branches about equally developed, or one branch may be longer in presence of developed oocytes or egg; oviduct cells finely granular; sperm cells, when present, spread along uterus, no spermathecae; vagina more or less barrel-shaped, short [average 8 µm long or 22% of corresponding body diameter (cbd)]; pars refringens vaginae in optical section with minute (1.0–1.5 µm), rounded, triangular to oval sclerotized pieces, slightly obliquely oriented, tips 2.0–2.5 µm apart; vulva at about midbody (average 55%) and a longitudinal slit in ventral view. Sublateral body pores mostly absent (observed in only three specimens from type population); could be obscured by swelling of body cuticle.

Code oithin the tabular identification key (based on: Decraemer and Baujard 1998): For males:A 212 (average, min., max.), B11, C22, D1, E0, F3, G2, H23, I2(4), J1, K2, L2, M27, N25, O1, P1. For females: A212 (average, min., max.), B11, C11, D1, E23, F2 (4), G3, H53, I1, J13, K2, L3, M1, N1, O2, P25, Q4(1), R2, S1, T1.

Remarks: In three females, lateral body pores were observed (Q1), one postvulvar sublateral pore at nearly 2.5 vaginal body diameter from vulva, and one prevulvar sublateral body pore six body diameters anterior to vulva.

Diagnosis and relationships: Paratrichodorus uliaensis sp. nov. is characterized in both sexes by the rather short onchiostyle (smaller than 40 µm) of 33.5 (30–37) µm in males and 35.4 (34–37) µm in females; in males by presence of a single CP, testis with small sperm cells with small nucleus (2.5 × 1.5 µm), and often fibrillar appearance, medium-sized spicules [44.5 (42–47) µm] with marked capitulum and three precloacal supplements with the posterior two within distal half of retracted spicules, and in females by the very short, less than 25% of corresponding body diameter or 22.4% (20.7–23.7 %), barrel-shaped vagina with minor midway indentation at level of constrictor muscles, minute rounded triangular sclerotized pieces, oblique in orientation and clearly separated from one another, sublateral body pores mostly not observed and vulva in ventral view a longitudinal slit. Sperm spread along uteri.

Based upon the tabular identification keys for males (Decraemer and Baujard 1998), sorting on primary features F (number of ventromedian precloacal supplements), feature D (number of CP), and P (habitus) the new species belongs to species group 6. Further sorting by feature N (type of sperm cells: small cell with small nucleus) grouped the new species with P. catharinae Vermeulen and Heyns 1983 , P. meyeri De Waele and Kilian 1992 , P. paraporosus Khan et al. 1989 , and P. tunisiensis ( Siddiqi 1963 ) Siddiqi 1974. Paratrichodorus uliaensis sp. nov. can be distinguished from these four species by a shorter onchiostyle (feature B), average less than or equal to 40 µm.

For females, sorting on primary features D and C, followed by L and K, resulted in a classification in subgroup 1-12 in Decraemer and Baujard (1998). Further sorting on type of sperm cells (feature P) grouped the new species with the known species P. acaudatus ( Siddiqi 1960 ) Siddiqi 1974, P. allius , and P. teres (subgroup 1-12) from which it can be distinguished by the shorter onchiostyle (<40 µm vs.>40µm). The new species agrees with P. acaudatus in male being common but differs in vagina shape (quadrangular in P. acaudatus ) and in male characteristics such as absence of CP and much longer spicules in P. acaudatus . Paratrichodorus uliaensis sp. nov. differs from both P. allius and P. teres by males being common, from P. allius by location of sperm, i.e. only in the uteri and not in ovarial sac, and from P. teres in shape of vagina without widened midpart.

Figures

Figure 1. Line drawings of Paratrichodorus uliaensis sp. nov.. Male.A* B* pharyngeal region.C* spicules. D* G* posterior body region with copulatory apparatus. E* F* anterior part of testis. Female paratypes. H* I* pharyngeal region.J* K* reproductive system: posterior branch and total system.L* N* vagina region.M* tail region.Holotype male* A* D; paratype male* F; paratype male* E. Specimens from La Rambla locality. Scale bars = 20 µm.

Figure 2. Light micrographs of Paratrichodorus uliaensis sp. nov.. A–D* holotype male.A* pharyngeal region.B* total view. C* testis; D* tail region with copulatory apparatus. Female paratypes. E* reproductive system. F* G* vagina region. Scale bars A* C-G = 10 µm; B = 100 µm.

Figure 3. Line drawings for comparison of vagina in the Paratrichodorus allius species-complex group. A* B* P. uliaensis sp.nov.; C* D. P. benalupensis sp. nov.; E* P.hinogerus sp. nov.; F* G* P.tarifaensis sp. nov.; H* P.asidonaensis sp.nov.; I* P. rocianerus sp. nov.; J* P.litoralis sp. nov.; K* L* P. paraallius sp. nov.; M–P* P.allius based on Sturhan %1989); Q* P.allius* paratype; R* S* P.teres* paratypes.