Minolaimus distalamphidus, Lu & Sui & Huang, 2022

Lu, Yang, Sui, Xinxin & Huang, Yong, 2022, Three new species of free-living marine nematodes from the central basin of the South China Sea, Journal of Natural History 56 (17 - 20), pp. 1091-1107 : 1098-1099

Minolaimus distalamphidus sp. nov.

( Figures 3–4 and Table 2 )

Type material

One male was obtained and measured. The holotype male is on slide NHS58-207-8 . Type locality and habitat

Undersea muddy clay sediment at Station S 58 in the South China Sea (15.712°N, 110.750° E, water depth 733 m) .

Etymology

The species name is derived from the Latin adjective distalis (away from) and amphid, referring to the amphid being located far from the anterior end.

Measurements

All measurement data are given in Table 2 .

Description

Holotype male. Body slender with filiform tail. Cuticle marked by transverse rows of punctations, with lateral differentiation consisting of six longitudinal rows of larger dots from the level of amphidial fovea to tail conical portion. Lateral differentiation about 6 μm in width. Cuticular pores not observed. Head slightly rounded and set off. Buccal cavity minute, without tooth. Six inner labial sensilla papilliform. A ring of six outer labial sensilla setiform, located just anterior to the ring of four cephalic setae, all of the setae 3.5 µm long. amphidial fovea multispiral with 8.5 turns, appearing oval in outline, 76% of corresponding body diameter in width. Pharynx cylindrical, not enlarged at its base. Cardia conical. Nerve ring surrounding the pharynx at about 42% of its length from the anterior end. Excretory pore not observed. Tail about 12 times as long as abd, conical with distal three-quarters filiform portion, without terminal setae.

Reproductive system diorchic, testes opposed, outstretched. Spicules symmetrical, slightly arcuate, 1.2 times as long as abd. Gubernaculum rod-like, straight and parallel to the spicule, without apophysis. Seventeen sucker-shaped cuticularised precloacal supplements equally arranged. The most posterior supplement located at 17 µm in front of cloaca and the most anterior one 185 µm from the cloaca.

Female not found.

Figures

Figure 3. Minolaimus distalamphidus sp. nov. (a) Anterior region of male, showing amphid and lateral differentiation; (b) pharyngeal region; (c) posterior region, showing tail; (d) cloacal region, showing spicule, gubernaculum and precloacal supplements. Scale bars: 20 µm.

Figure 4. Minolaimus distalamphidus sp. nov. (a, b) Anterior end of male, showing anterior sensilla and amphidial fovea; (c) cuticle in the middle of body, showing lateral differentiation; (d) cloacal region of male, showing spicule, gubernaculum and precloacal supplements; (e) posterior part of body. Scale bars: a, b, d = 20 µm; c = 10 µm; e = 50 µm.