Bathylaimus huanghaiensis, Huang & Zhang, 2009

Huang, Y. & Zhang, Z. N., 2009, Two new species of Enoplida (Nematoda) from the Yellow Sea, China, Journal of Natural History 43 (17 - 18), pp. 1083-1092 : 1088-1090

Bathylaimus huanghaiensis sp. nov.

( Figures 3 and 4 )

Type material

Holotype: „ 1, Specimen number of new species: LU009 (Slide number: LUR 08302); paratypes: „ 2, „ 3, „ 4, „ 5, „ 6, ♀ 1, ♀ 2, ♀ 3 LU010-017 ( LUR08303-04 , LUH 08503)

Type locality and habitat

Intertidal sandy sediment in the Yellow Sea, from Rizhao to Huangdao (Qingdao): 119 ° 34 9 E, 35 ° 26 9 N – 120 ° 10 9 E, 35 ° 59 9 N.

Etymology

This species is named after the sea area where the specimens were collected.

Measurements ( Table 2)

{327 W 2337

Holotype „ 1: 2447mm; a~138:2, b~5:8, c~6:8, Sc~29

26 36 36 34

{346 V 2313

Paratype ♀ 1: 2428mm; a~54:0, b~7:0, c~21:1, V %~54:6%

26 37 45 29

Description

Males. Body length 2340 mm (2177–2447 mm). Maximum diameter 34 mm (31– 36 mm). Cuticle smooth. Mouth surrounded by three rounded lips which are incised. Labial sensilla are setiform. Six long three-jointed cephalic setae, 16–19 mm long (0.7 h.d.); four short two-jointed setae, 6–7 mm long. Buccal cavity relatively smaller than in other species, and in two separate sections: the anterior broad, rectangular, heavily cuticularized with a big triangular dorsal tooth (5–6 mm long); the posterior small, weakly cuticularized, without tooth. Amphids subspiral of 1.2 turns, 0.28 times c.d. in diameter, posterior to the base of buccal cavity, about one head diameter from the anterior end. Pharynx cylindrical, 0.13 times body length. Nerve ring 0.42 times pharynx length from anterior end. Tail conical 3.5 (3.2–3.9) a.b.d. long, scattered several short setae, three caudal glands.

Spicules slender, slightly straight, about 30 mm long. Gubernaculum 26 mm long, kidney-like with thickened ventral rib and narrow ala. Apophysis present.

Females. Similar to the males in most respects, but slightly wider, maximum diameter 43 mm (vs. 34 mm of males); tail setae absent. Ovaries paired, opposed, reflexed. Vulva at about 55% of body length.

Differential diagnosis

This new species is closely related to Bathylaimus stenolaimus Stekhoven and De Coninck. It is differentiated by the following characters. Cuticle smooth, not striated. The anterior buccal cavity with only one distinct dorsal tooth; the posterior part small and without tooth. Amphids subspiral of 1.2 turns. Long cephalic setae three-jointed.

Remarks

The genus Bathylaimus was erected by Cobb in 1894 with the type species B. australis Cobb. It differs from the closest genus Tripyloides by the deeply incised lips, rounded spiral amphid and buccal cavity in two sections. Up to now, a total of 36 species are known from this genus ( Gerlach and Riemann 1974; Platt and Warwick 1983; Keppner 1988; Electronic database: http://nemys.ugent.be), and only one species, Bathylaimus stenolaimus Stekhoven et De Coninck has been recorded in China (Huang et al. 2006).

Figures

Figure 3. Bathylaimus huanghaiensis sp. nov. (A) lateral view of male anterior body part, showing pharynx and nerve ring; (B) lateral view of male head end, showing three-jointed cephalic setae, buccal cavity, dorsal teeth and amphid; (C) lateral view of male tail end, showing spicules, gubernaculum and tail setae; (D) lateral view of female tail, showing three caudal glands.

Figure 4. Bathylaimus huanghaiensis sp. nov. (A) lateral view of male head end, showing threejointed cephalic setae; (B) lateral view of female head end, showing two sections of buccal cavity; (C) lateral view of male head end, showing subspiral amphid; (D) lateral view of male head end, showing buccal cavity and a distinct dorsal teeth; (E) lateral view of male tail, showing spicules and gubernaculum; (F) lateral view of male body part, showing spicules and gubernaculum; (G) lateral view of female body, showing eggs and ovary; (H) lateral view of male body.