Acanthopharynx dormitata Leduc & Zhao, 2016

Leduc, Daniel, 2024, Four new free-living marine nematode species (Plectida: Ceramonematidae) and two new species records (Desmodorida: Desmodorinae) from Rangitāhua / Kermadec Islands, Aotearoa / New Zealand, European Journal of Taxonomy 970, pp. 138-174 : 168

Acanthopharynx dormitata Leduc & Zhao, 2016

Fig. 13 , Table 4

Diagnosis

Acanthopharynx dormitata characterised by cephalic capsule with crown of 14 setae (four cephalic and ten subcephalic setae) and 24 additional subcephalic setae arranged in eight longitudinal rows, unspiral amphidial fovea, buccal cavity with crown of denticles, female reproductive system with spermatheca, male with nine precloacal and two postcloacal supplements, and gubernaculum surrounding spicules distally.

Material examined

NEW ZEALAND • 1 ♂; Kermadec Islands , Raoul Island (Homestead); 29.23660° S, 177.92683° W; depth 19 m; 22 Nov. 2021; coarse sand and gravel sediments, voyage TMOR2021 , station 84; NIWA 154953 .

Type habitat and locality

Red seaweed partially covered in sediments and growing on boulders of the lower intertidal zone, Greta Point, Wellington, New Zealand (174.80489° E, 41.30356° S).

Remarks

The male Raoul Island specimen agrees well with the description of the species based on the Wellington specimens by Leduc & Zhao (2016) with respect to cuticle ornamentation, arrangement and size of anterior sensilla, buccal cavity armature, amphid shape, pharynx structure, shape of copulatory structures, shape and number of precloacal and postcloacal supplements, and tail morphology. The Raoul Island specimen, however, has a longer body (2954 vs 1809–2311 µm in the Wellington specimens), higher ratio of a (62 vs 38–50 in Wellington specimens) and c (35 vs 22–29 in Wellington specimens), slightly larger amphid (36 vs 25–30% cbd in Wellington specimens) and shorter spicules (49 vs 59–62 µm in Wellington specimens) and gubernaculum (24 vs 27–29 µm in Wellington specimens) ( Table 4 ). It could be argued that the latter discrepancies justify the erection of a new species; however, more specimens need to be observed and molecular data need to be obtained before to inform this decision. For the time being, the Raoul specimen is considered to belong to Acanthopharynx dormitata .

Figures

Fig. 13. Acanthopharynx dormitata Leduc & Zhao, 2016, ♂ (NIWA 154953). A. Entire body. B. Pharyngeal region. C. Cephalic region and buccal cavity. D. Cloacal and tail region. E. Sperm. Scale bar: A = 200 µm; B = 85 µm; C = 22 µm; D = 44 µm; E = 26 µm.