Paracyatholaimus huanghaiensis, Huang & Xu, 2013

Huang, Yong & Xu, Kuidong, 2013, Two new species of the genus Paracyatholaimus Micoletzky (Nematoda: Cyatholaimidae) from the Yellow Sea, Journal of Natural History 47 (21 - 22), pp. 1381-1392 : 1386-1390

Paracyatholaimus huanghaiensis sp. nov.

( Figures 3 , 4 )

Type material

Four males and three females were measured and studied. Holotype: ♂ 1, on slide RS110322-20; paratypes: ♂ 2, ♂ 3, ♂ 4, ♀ 1, ♀ 2, ♀ 3 on slide RS110322-6, RS110322-12 and RS110322-14.

Type locality and habitat

Intertidal sandy beach of Rushan city coast (37 ◦ 15 ′ N, 122 ◦ 10 ′ E).

Etymology

This species is named after the sea area of the type locality.

Measurements

Measurements are given in Tables 3 and 4.

Male. Body cylindrical with little attenuation on both ends. Cuticle transversally annulated and punctated. The punctations about the same size along the body. No clear lateral differentiation. Body pores arranged in eight longitudinal rows. Somatic setae short, in four sublateral rows.

Anterior end truncate. Mouth opening surrounded by six lips, inner labial sensilla papillose. The six outer labial setae and the four cephalic setae arranged in one circle. Four cephalic setae slightly shorter than six outer labial setae. Amphidial fovea round in outline, multispirally coiled with four turns in the males and 3.5 turns in the female, just posterior to dorsal tooth of buccal cavity (located 16 µm from the anterior end).

Cheilostoma cup-shaped, its walls reinforced by triangular rugae apparently 12 in number. Buccal cavity with one large pointed sclerotized dorsal tooth and two smaller ventrosublateral teeth.

Pharynx cylindrical. Cardia poorly visible. Nerve ring not clear. Ventral gland just under the pharyngeal base, but excretory pore hardly visible.

Tail conical with distal third cylindrical. Three caudal glands. Terminal spinneret tube well developed. There are a few longitudinal rows of setae on the tail.

Diorchic; anterior testis outstretched, posterior smaller testis reflexed. Anterior testis situated to the right of the intestine, posterior testis to the left of the intestine. Spicules slender, curved, distally pointed. Gubernaculum handle shaped, expanding distally to a plate, with some sawteeth at distal end. Three papillose precloacal supplements. Each papilla protruding as a cone-shaped structure with cuticularized narrow ducts. Posteriormost one and anteriormost one 20 µm and 80 µm in front of cloaca, respectively. Testes not observed.

Female. Similar to the male in most respects. Ovaries paired, opposed, reflexed, anterior ovary and posterior one 160 µm and 110 µm from vulva, respectively; vulva at post-midpoint of body length.

Differential diagnosis and discussion

Paracyatholaimus huanghaiensis sp. nov. is characterized by cylindrical body with conic-cylindrical tail; spicules slender, curved, distally pointed; gubernaculum handleshaped, expanding distally to a plate, with some sawteeth at distal end; three papillose precloacal supplements, each papilla protruding conically with cuticularized narrow ducts. The new species resembles Paracyatholaimus pesavis Wieser and Hopper, 1967 and Paracyatholaimus botosaneanui Andrássy, 1973 in number of precloacal supplements and shape of gubernaculum. But the new species differs from P. pesavis by larger body (1640–2136 by 51–65 µm versus 1080–1170 by 35–44 µm), longer spicules (60 µm versus 30 µm), amphid with four turns versus five turns, and the distal third papilla prominent versus very faint. The new species differs from P. botosaneanui by number of precloacal supplements, three versus four.

Figures

Figure 3. Paracyatholaimus huanghaiensis sp. nov. (A) Lateral view of female, showing vulva, ovary and egg; (B) lateral view of male head end, showing buccal cavity, amphideal fovea and cephalic setae; (C) lateral view of male pharynx posterior end, showing ventral gland; (D) lateral view of male posterior body part, showing spicules, gubernaculum and precloacal supplements.

Figure 4. Paracyatholaimus huanghaiensis sp. nov. (A) Lateral view of male head end, showing cephalic setae, amphideal fovea and cuticle punctuation; (B) lateral view of male head end, showing buccal cavity and dorsal tooth; (C) lateral view of male tail end, showing gubernaculum; (D) lateral view of male tail end, showing precloacal supplements.

Tables

Table 3. Measurements of male holotype and one female paratype of Paracyatholaimus huanghaiensis sp. nov.

Holotype ♂ 1:	−	298	M	1923	2049 µm
	29	60	62	43	a = 33.0, b = 6.9, c = 16.3, Spic = 42
Paratype ♀ 1:	−	320	V	1880	2030 µm
	31	56	65	43	a = 31.2, b = 6.3, c = 13.5, V% = 51%