Paratrichodorus litoralis, 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 : 29-31

Paratrichodorus litoralis sp. nov. Decraemer et al.

( Figs 3J , 14 , 15 ; Table 8)

Zoobank registration: urn:lsid:zoobank.org:act:B7070089-B833-43C5-B38C-CF4112497D1B

Type material: Holotype. Male extracted from soil samples collected from the rhizosphere of marram grass % Ammophila arenaria ) at Pantanagianni * Brindisi province * southern Italy % 40°45 ʹ 01.27 ʹʹ N latitude* 17°43 ʹ 13.65 ʹʹ E longitude) by N. Vovlas * mounted in pure glycerine and deposited in the nematode collection of Ghent University * Ghent * Belgium %slide number UGMD 104467 ).

Paratypes: Male and female paratypes extracted from soil samples collected from the rhizosphere of marram grass at Pantanagianni * Brindisi province * southern Italy * were deposited in the following nematode collections: Ghent University * Ghent * Belgium %slide numbers males and females paratype UGMD 104467-104469 * UGMD 104461 ); and one male and one female paratypes at the USDA Nematode Collection* Beltsville* MD * USA %collection number T-8021p ).

Additional material examined: An additional population was collected also in the rhizosphere of marram grass at Cullera * Valencia province * Spain %39°15 ʹ 64.7 ʹʹ N latitude* 0°24 ʹ 08.2 ʹʹ W longitude); unfortunately the specimens of this population were not in good conditions for light microscopic study* and were identified only molecularly .

Etymology: Ŋe species epithet 8s derived from the Latin litoralis = pertaining to the seashore* and refers to the coastal environment where the type specimens were collected.

Description of male: Body nearly 750 µm long %average) straight* cigar-shaped* with cuticle swollen upon fixation %5 µm at midbody); anteriorly 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 long %average 56 µm long); reserve onchium %21.5 µm average) present in all adults. Pharynx at posterior isthmus gradually widening to a posterior bulb and a short dorsal overlap by the intestine. Nerve ring surrounding isthmus; SE-pore opposite isthmus. Ventromedian or lateral cervical papillae absent. Reproductive system monorchic* sperm small with oval-shaped nucleus %3.0 × 1.5 µm). Spicules medium-sized %average 54.5 µm)* slightly ventrally curved* with short slightly wider capitulum* blade largely equally wide but slightly tapered towards an open distal tip; spicules ornamented with fine* transverse striae* except at extremities. Copulatory muscles hardly developed* obscure; capsule of suspensor muscles thin* surrounding anterior half of spicule; gubernaculum with thickened distal part parallel to spicules. Bursa narrow* extending usually from head of retracted spicule to subterminally on tail. Ŋree precloacal supplements* posterior two %SP1 and SP2) opposite distal two-thirds of retracted spicules; anteriormost SP3* liưle developed and non-protruding* located about 2.5 spicule length anterior to retracted spicules. A pair of well-developed postcloacal supplements close to the cloacal opening; cloacal lips may be slightly protruding. Tail short* less than one anal body diameter long* conical. A pair of caudal pores subterminally near tail tip.

Description of female: Body similar in appearance and size as in male* except for male reproductive system and features. Onchiostyle equally long* with a reserve stylet in adults; pharyngo-intestinal junction with dorsal overlap 16–24 µm* rarely combined with a short ventral overlap. Reproductive system with both genital branches about equally long and without spermatheca but small sperm with small nucleus spread over the uteri; vagina barrel-shaped with minor indentation at level weak constrictor muscles; vaginal sclerotization pieces very small %1.0 µm)* rounded triangular* clearly apart %2.0–3.0 µm)* slightly oblique and vulva a longitudinal slit in ventral view. Tail with caudal pores.

Code oithin the tabular identification key (based on: Decraemer and Baujard 1998): For male: A212 %average* min.* max.)* B22* C22* D0* E0* F3* G2* H2* I4* J2* K2* L2* M27* N2* O1* P1. For female: A222 %200)* B23* C1* D1* E2* F3%4)* G3* H3* I1* J1* K1* L3* M1* N1* O2* P2* Q-* R2* S1* T1.

Diagnosis and relationships: Paratrichodorus litoralis sp. nov. is characterized by a medium-sized body %average 740 µm in male* 790 µm in female)* rather long onchiostyle %average 57 µm in male* 60 µm in female)* absence of ventromedian and lateral cervical papillae in male* spicule length average 55 µm* three precloacal supplements with the posterior two opposite the distal two-thirds of the retracted spicules. Females with barrel-shaped vagina* one-fissh of corresponding body width* and with minor indentation; minute vaginal sclerotized pieces %1 µm)* slightly oblique and clearly separated %2.2–3 µm); sperm spread over uteri. Both sexes with a reserve onchium in adults* dorsal overlap by the intestine and caudal pores present.

Based upon the tabular identification key for Paratrichodorus males %Decraemer and Baujard 1998)* sorting of the data primarily on character D %number of ventromedian cervical papillae)* followed by character F %number of precloacal supplements) groups P. litoralis sp. nov. with the known species P. allius * P. teres * and P. rhodesiensis * and with previously described P. tarifaensis sp. nov. that shows similar measurements of body length* onchiostyle* and spicule length. It also groups with P. lobatus and P. namibiensis %partim) with males with exceptionally 3 SP. Paratrichodorus litoralis sp. nov. differs from all by the presence of a reserve onchium in the adult* and from P. teres * P. namibiensis * and P. lobatus in the non-fibrillar appearance of sperm vs. thread-like or fibrillar. Ŋe new species also differs from all known species by the longer onchiostyle %average>55 µm vs. <55 µm) and by the longer spicule length than in P. allius * P. rhodesiensis * and P. teres %average>50µm vs. <50 µm) but similar as in P. lobatus and shorter than in P. namibiensis %average 67 µm).

Based upon the tabular identification keys for females %Decraemer and Baujard 1998)* sorting on primary features D and C* followed by L and K* resulted in a classification in subgroup 1-12 of group 1. Further sorting on feature P % type of sperm cell)* feature O %location of sperm) and feature N %presence of males) groups P. litoralis sp. nov. with known species P. acaudatus and P. allius . Paratrichodorus litoralis sp. nov. differs from both by the presence of a reserve onchium in adult* a feature it has in common with P. benalupensis sp. nov.. It further differs from P. allius by the longer onchiostyle %58–64 µm vs. 37–48 µm)* the longer spicules %50–58 µm vs. 31 µm)* the male–female ratio* with males as common as females vs. males rare* and by the short dorsal overlap by the intestine vs. a ventral overlap in P. allius .

Paratrichodorus species without males but females with sperm at tip of ovary

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 14. Line drawings of Paratrichodorus litoralis sp. nov.. A* total view female paratype. B* pharyngeal region female paratype. C* tail region and copulatory apparatus* male paratype.D* protruding spicule* paratype. E* posterior body region* holotype male.F* pharyngeal region paratype male.G* female reproductive system* paratype.H* testis* germinal zone* paratype. Scale bars = 20 µm.

Figure 15. Light micrographs of Paratrichodorus litoralis sp. nov.. A* total view paratype female.B* anterior body region* arrow points to reserve onchium* paratype female. C* vagina region* paratype. D* posterior genital branch* paratype female.E* anterior body region* arrow points to reserve onchium* paratype male; tail region with copulatory apparatus* holotype male. Scale bars A = 100 µm; B* E = 20 µm; C* D = 10 µm.