Pristionchus musae, Kanzaki & Herrmann & Weiler & Röseler & Theska & Berger & Rödelsperger & Sommer, 2021

Kanzaki, Natsumi, Herrmann, Matthias, Weiler, Christian, Röseler, Waltraud, Theska, Tobias, Berger, Jürgen, Rödelsperger, Christian & Sommer, Ralf J., 2021, Nine new Pristionchus (Nematoda: Diplogastridae) species from China, Zootaxa 4943 (1), pp. 1-66 : 35-40

Pristionchus musae n. sp.

urn:lsid:zoobank.org:act:E015F8AB-4F6F-46B1-A96A-85F724C7448F

Etymology. The species name is derived from the associated substrate from which the species was recovered. The strain was isolated from a rotting pseudostem of a plant of the banana family ( Musa sp.) with soil material.

Measurements. See Table 4

Adult. General characters are as described above for the triformis -group.

Stenostomatous form. Cheilostom, gymnostom, pro-mesostegostom and telostegostom as described above. 12- plated form was not found during observation. Arrangement of tooth and denticles in metastegostom as described above; dorsal movable tooth triangular, anterior end slightly curved, tooth often directed anteriorly; left subventral ridge with three minute, blunt or pointed adventitious denticles on a plate; right subventral ridge with three distal rounded or blunt adventitious denticles. Whole stoma including the tooth and denticles is narrow and more pointed in males.

Eurystomatous form. Cheilostom as described above, anterior half of each cheilostomal plate often split into two tips to form 12-flapped form. Six-flapped form (without split cheilostomal plate) rare. Gymnostom in both types 1 and 2 short and thick, forming cuticular ring. Pro-mesostegostom well-developed, internally overlapping with posterior end of gymnostom; type 1 form short, somewhat flattened and bearing weak serrates at anterior end; type 2 with small spines sparsely on inner surface. Arrangement of tooth and denticles in metastegostom as described above; dorsal movable tooth claw-like as typical of the genus; left subventral ridge with three large plates, each often has split tips and extra denticles on middle forming spiny plate; right subventral movable tooth claw-like and often bears extra peak on the ventral side. Telostegostom as described above.

Male. Paired papillae and phasmid are arranged as <v1, v2d, v3, co, v4, ad, (ph, v5, v6, v7, pd)>, where v1 located about 1 CBD anterior to co; v2d less than 1/5 CBD anterior to co; v3 adcloacal; v4 at 1/3 CBD posterior to co, i.e., v2d, v3, co and v4 are close to each other; ad about 1 CBD posterior to co; ph at 2/3 way from ad and the root of tail spike; v5–v7 forming triplet, just posterior to ph; and pd around level of v7, i.e., ph, triplet papillae and pd are very close to each other. v1, v3, v4 and ph subventral, v2d and ad lateral, v5–7 ventral, pd subdorsal in male tail. General shape of spicule and gubernaculum as described above.

Female. Gonadal characters of female as described above. Tail elongate conoid with slightly filiform terminus, i.e., the posterior half of tail is more elongated compared with anterior part. Phasmid ventro-laterally located at about 1.5 ABD posterior to anal opening.

Diagnosis and relationships. Pristionchus musae n. sp. is characterized by the slightly anteriorly curved triangular dorsal tooth and the right and left subventral ridges with three denticles of stenostomatous form, right subventral stegostomal tooth which often has blunt peak on the ventral side in eurystomatous form, sparsely serrated pro-mesostegostomal wall in type 2 eurystomatous form, the arrangement of male genital papillae, <v1, v2d, v3, co, v4, ad, (ph, v5, v6, v7, pd)> where v2d, v3, co and v4 and ph, v5, v6, v7, pd are close to each other, respectively, and a long spike of male tail. Pristionchus musae n. sp. is typologically close to P. hoplostomus . The new species and P. hoplostomus share a triangular and pointed dorsal tooth in stenostomatous form, right subventral tooth in eurystomatous form, often have an extra peak on its ventral side, and the arrangement of genital papillae, closely located v2d, v3, co and v4. The new species is distinguished from P. hoplostomus by the absence vs. presence of 12-plated stenostomatous form, and dorsal tooth of stenostomatous form, i.e., the tooth is somewhat larger and more anteriorly directed in P. hoplostomus than P. musae n. sp. Further, the new species is distinguished from all other species by mating experiments and also characterized by a ca. 1,600-bp fragment of the SSU rRNA gene (GenBank accession number MW017220 ), the sequence of which is distinct from that of all other Pristionchus species.

Type host and locality. Pugao Laozhai village , close to road, Yuanyang, Yunnan province, PRC .

Type material and type strain. Type strain RS5987 frozen at the nematode collection of the MPI Tübingen and available as living culture upon request. Voucher specimens sent to the following museums: Holotype male, Paratype male and female: Museum für Naturkunde Karlsruhe , Germany ; Paratype male and female: Swedish Natural History Museum, Stockholm, Sweden ; Paratype male and female: University of California in Riverside Nematode Collection ( UCRNC), Riverside , CA, USA .