Paratrichodorus benalupensis, 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 : 10-12

Paratrichodorus benalupensis sp. nov. Decraemer et al.

( Figs 3C, D , 4 , 5 ; Table 3)

Zoobank registration: urn:lsid:zoobank.org:act:FB05C936-0F15-4624-997A-9C54782EE924

Type material: Holotype. Male extracted from soil samples collected from the rhizosphere of unidentified grasses at Benalup-Casas Viejas * Cádiz province * southern Spain % 36°18 ʹ 24.33 ʹʹ N latitude* 5°52 ʹ 52.38 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 104450 ).

Paratypes: Male and female paratypes extracted from soil samples collected from the rhizosphere of unidentified grasses at Benalup-Casas Viejas * Cádiz province * southern Spain * were deposited in the following nematode collections: Ghent University * Ghent * Belgium %slide numbers males and female paratype UGMD 104450 * UGMD 104453 ); and one male and one female paratypes at the USDA Nematode Collection* Beltsville* MD * USA %collection number T-8016p ).

Etymology: Ŋe species epithet refers to Benalup-Casas Viejas* the type locality where the type specimens were collected.

Description of male: Body nearly straight* cigar-shaped* with swollen cuticle %average 4 µm at midbody) upon fixation; anteriorly clearly tapered to narrower* rounded* low-lip region appearing offset by the protruding double papillae %four cephalic and two subdorsal and two subventral outer labial papillae) and swelling of body cuticle. Onchiostyle rather small %average 37 µm long); reserve onchium %14–17 µm) present in all adults. Pharynx at posterior isthmus either gradually widening to a posterior bulb with a combined short ventral overlap of ventrosublateral pharyngeal glands and short dorsal intestinal overlap; posterior ventrosublateral gland nuclei at some distance from dorsal gland nucleus. Nerve ring surrounding isthmus; SE-pore opposite anterior pharyngeal bulb when pharynx relaxed. A single ventromedian CP at rather short distance %9–15 µm) anterior to SE-pore. Reproductive system monorchic* testis with short germinal zone %34 µm in holotype) and sperm with small* round to oval-shaped nucleus %2.0–2.5 µm × 1.5 µm)* closely packed* giving the vesicular seminalis a fibrillar appearance. Spicules medium-sized %average 48 µm)* nearly straight* with marked capitulum* blade largely equally wide* transversely striated except anterior end with capitulum and in tapered distal end. Copulatory muscles hardly developed and obscure; capsule of suspensor muscles very thin* around anterior half of spicule; gubernaculum with thickened distal part* parallel to spicules. Bursa narrow* extending largely along spicule region to subterminally on tail. Ŋree precloacal supplements* posterior two %SP1 and SP2) more or less at level of distal half of the retracted spicules with SP1 midway between cloacal opening and SP2; SP3 liưle developed and non-protruding* located about two spicule lengths from the cloacal opening. A pair of well-developed postcloacal supplements close to the cloacal opening; the anterior cloacal lip bifid with two thin-walled protrusions. 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.

Description of female: Body straight to slightly ventrally curved; largely similar to male* except for reproductive system and male secondary features. Digestive system with a combined dorsal intestinal and a ventral pharyngeal overlap; reserve onchium %12 µm) present in all females. Secretory-excretory pore opposite anterior end of pharyngeal bulb. Reproductive system didelphic-amphidelphic with both branches about equally developed* or one branch longer in the presence of developed oocytes or egg; oviduct cells finely granular; sperm cells* when present* spread along uteri* no spermathecae; vagina more or less barrel-shaped with minor indentation at level of constrictor muscles* about 25% of corresponding body width long; pars refringens vaginae in optical section with minute %1 µm) rounded triangular to oval sclerotized pieces* obliquely oriented* tips separated by 3 µm %average); vulva at about midbody %average 52%). No sublateral/subventral body pores observed.

Code oithin the tabular identification key (based on: Decraemer and Baujard 1998): For males: A 222* B1%2)* C2* D1* E0* F3* G2* H3* I4* J1* K2* L2* M27* N5* O1* P1. For females: A222* B12* C1* D1* E3* F4* G-* H33* I1* J1* K12* L3* M1* N1* O2* P2* Q4* R2* S1* T1.

Diagnosis and relationships: Paratrichodorus benalupensis sp. nov. is characterized by body medium-sized %average 900 µm in female; 775 µm in male)* onchiostyle medium-sized %average 41 µm in female* 39 µm in male)* and all adults with a reserve onchium. Male with a single CP* shortly anterior to SE pore; straight spicules with marked capitulum* small sperm cells with clear nucleus closely packed giving fibrillar appearance and thereby giving the vas deferens a striated appearance; three precloacal supplements* the posterior two more or less at level of the posterior half of the retracted spicules; a pair of postcloacal supplements near cloacal opening; the laưer with pronounced bifid anterior lip. Females with vulva more or less barrel-shaped* about 25% of corresponding body width long; vaginal sclerotized pieces in optical section minute %1 µm)* rounded triangular to oval shaped* obliquely oriented* tips separated by 3 µm %average). Sperm spread over uteri. No sublateral/subventral body pores observed.

Use of the tabular identification key for Paratrichodorus males %based on Decraemer and Baujard 1998) and sorting by primary feature D* followed by feature N %sperm cells)* grouped the P. benalupensis sp. nov. together with P. catharinae * P. meyeri * P. paraporosus * P. tunisiensis * and the previously described new species P. uliaensis sp. nov.. It differs from the known species %except P. paraporosus ) by the shorter onchiostyle ≤40 µm vs.>40 µm and from P. tunisiensis also in spicule shape [straight vs. more curved % type population* populations from Italy; Siddiqi 1963 * Roca and Lamberti 1984* Tanha Maafi and Decraemer 2002)] and from P. paraporosus in the presence of only three SP instead of four SP. Paratrichodorus benalupensis sp. nov. can be distinguished from all four species by the presence of a reserve onchium in the adult. Ŋe presence of a reserve onchium in the adult is the main feature to distinguish it from P. uliaensis sp. nov..

For females of the Benalup sample* sorting on primary features D and C* followed by L and K %variable)* resulted in a classification in subgroups 1-11 or 1-12 in Decraemer and Baujard %1998); further sorting on feature P % type of sperm cells) and feature N %occurrence of males) groups P. benalupensis sp. nov. with P. acaudatus and P. tunisiensis * P. lobatus %Colbran 1965 ) Siddiqi 1974* and the previously described P. uliaensis sp. nov.. Ŋe new species differs from all these species by the presence of a reserve onchium in the adult and from all known species by the shorter onchiostyle* a feature it has in common with the previously described new species. So far* the presence of a reserve onchium in all specimens of a population has only been used as a diagnostic feature in the genus Nanidorus to differentiate Nanidorus minor and N. nanus % Allen 1957 ) Siddiqi 1974 from the other species. In all other examples this criterion is considered as accidental %see Discussion). Except for the presence of a reserve onchium in the adult of P. uliaensis sp. nov. * this species is almost undistinguishable morphologically from P. benalupensis sp. nov. * being described here as separate new species* based on the additional support given by morphometrical and molecular analyses %see below).

Figures

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.

Figure 4. Line drawings of Paratrichodorus benalupensis sp. nov.. Male.A* pharyngeal region.B* C* E* tail region with copulatory apparatus. E* in ventral view. D* testis* partim.Female paratype. F* pharyngeal region.G* vagina region. C* D* holotype. Scale bars = 20 µm.

Figure 5. Light micrographs of Paratrichodorus benalupensis sp. nov.. A* anterior body region. D* testis with germinal zone.E* region pharyngointestinal junction.F–H* posterior body region of male holotype with focus on spicule* gubernaculum and bursa respectively.Female paratype. B* anterior body region. C* vagina region.Scale bars A–H = 10 µm.