Campylaimus orientalis, Fadeeva, Natalia, Mordukhovich, Vladimir & Zograf, Julia, 2016

Fadeeva, Natalia, Mordukhovich, Vladimir & Zograf, Julia, 2016, RevIsIon of the genus Campylaimus (DIplopeltIdae, Nematoda) wIth descrIptIon of four new specIes from the Sea of Japan, Zootaxa 4107 (2), pp. 222-238 : 225-228

Campylaimus orientalis sp. nov.

( Figs 2–4 )

Locality: Table 1 .

Measurements. Table 2 .

Material examined. Holotype. Adult male, formalin-fixed, mounted on slide (MN A374-3), in glycerin. Allotype. Adult female, formalin-fixed, mounted on slide (MN A372-2), in glycerin. Paratypes. Male, slides (A371-23) and female (A373-3), same data as holotype.

Etymology. The species name is derived from the Latin “ orientalis ”, meaning “eastern”.

Description. Spindle-shaped plump nematodes with clearly annulated cuticle (ring height 2.0 µm), extending from the oral opening to the terminal part of the tail ( Figs 2 , 3 A, 3B). Anterior end with a clearly visible cuticular cap ( Fig. 4 D). Oral opening small, rhomboid, displaced on dorsal side of body. Buccal cavity unarmed. Inner labial papillae and outer labial setae not seen. Four short (2.5–3 µm) cephalic setae asymmetrically placed: latero-dorsal pair of short setae is located a little posterior to latero-ventral pair ( Fig. 3 С).

Amphids well developed, comprising 2 parallel limbs connected posterior to the oral opening; dorsal limb somewhat shorter (32–40 µm) than ventral (37–43 µm). Amphids with wide gap between limbs ( Fig. 3 C). Prominent narrow longitudinal alae extend along body to posterior end, arising immediately from ventral (long) limb of the amphid ( Fig. 3 A).

Pharynx cylindrical for most of its length, muscular, gradually widening to the base with developed cardia. Nerve ring surrounding posterior part of pharynx. Cardia short, embedded in intestine.

Tail conico-cylindrical, 123–135 µm long (4.6–5.9 a.b.d), gradually tapering toward the distal end, tip swollen, similar in shape in both sexes ( Figs 2 , 3 B).

Males with two testes, anterior testis situated left, posterior testis right of the intestine. Spicules equal in length, arcuate with cephalated proximal end. Gubernaculum tubular, 7 µm long. Two pairs of small postcloacal setae; first pair 4 µm long, situated 63 µm posterior to cloacal opening; second pair 90 µm posterior to cloacal opening ( Figs 2 , 4 B–C).

Females similar to male. Gonads paired, opposed; ovaries outstretched, non-reflexed. Anterior and posterior ovaries on left and right side of intestine, respectively. Vulval orifice ventral; vagina short, not thickened. Postcloacal setae absent. Two glands surrounding the vulva.

Diagnosis. Campylaimus orientalis sp. nov. is characterized by being spindle-shaped, having moderate body, cuticle with clear annulations, small rhomboid oral opening displaced on the dorsal side of the body, amphid with unequal limbs, prominent narrow longitudinal alae, spicules with a cephalated proximal end, and tubular gubernaculum.

Differential diagnosis. Based on the amphid structure, C. orientalis sp. nov. is similar to two congeners: C. mirus Gerlach, 1950 and C. rimatus Vitiello, 1974 , that are characterized by the prominent narrow longitudinal alae passing immediately from ventral limb of amphid along the body to the posterior end.

The specimens of C. orientalis sp. nov. differ from C. rimatus by the presence of a tubular gubernaculum (vs absent in C. rimatus ) and index c (5–6 vs 7–8, respectively). Campylaimus orientalis sp. nov. differs from C. mirus in numerous respects, including the amphid shape, long cardia embedded in the intestine (vs short in C. mirus ) and by having cephalated spicules (vs non-cephalated in C. mirus ) and a relatively broader body (а = 19–20 vs 42, respectively).

Figures

FIGURE 2. Campylaimus orientalis sp. nov. A: Entire body, male holotype; B: Posterior end of the holotype male. Copulatory apparatus, spicule, gubernaculum and postcloacal setae; C: Lateral view of male anterior body region; D: Entire body, female allotype. Scale bar: A = 100 µm; B = 50 µm; C = 100 µm; D = 100 µm.

FIGURE 3. Campylaimus orientalis sp. nov. SEM. A: Entire body of female; B: Posterior end of female; C: Amphidial fovea and cephalic setae on anterior end of female, lateral view. Scale bar: A = 20 Μm; B, C = 10 Μm. Abbreviation: al — alae.

FIGURE 4. Campylaimus orientalis sp. nov. SEM. A: Amphidial fovea on anterior end of male, lateral view; B: Posterior end of male with cloaca, ventral view; C: Posterior end of male with postcloacal setae, ventral view; D: Lateral view of female anterior body region. Scale bar: A, С = 10 Μm; B = 20 Μm; D = 2 µm. Abbreviations: amph. fov. — amphidial fovea; c. c. — cuticular cap; cl — cloaca; p. cl. s. — post cloacal setae; m—mouth opening.

Tables

TABLE 2. Measurements (Μm) of Campylaimus orientalis sp. nov. (range).

HOLOTYPE	ALLOTYPE	PARATYPES	PARATYPES
Male	Female	Male N=1	Female N=2
L 725.0	690.0	680.0	608.0–854.0
Maximum body diameter 38.0	37.0	40.0	30.7–55.0
Buccal cavity, length 4.0	4.0	4.0	4.0
Head diameter 9.0	9.0	9.0	7.0–9.0
Cephalic setae, length 3.0	3.0	3.0	2.0–3.0
Dorsal limb of amph. fovea 37.0	32.4	40.0	35.0–42.0
Ventral limb of amph. fovea 38.0	37.7	43.0	39.00–50.0
Amphidial fovea width 4	4.0	4	3 0–4.0
Lateral alae 2.6	2.6	2.6	2.0–2.0
Pharynx, length 128.8	140.0	120.0	105.0–160.0
Tail, length 123.2	130.0	128.0	135.0–121.0
Spicular, length 27.0	-	29.0
Anal body diameter 27.0	28.0	28.0	23.0–28.9
Gubernaculum, length 7.0	-	7.0
a 19.8	18.7	18.9	15.5–20.2
b 5.6	5.7	5.7	5.3–5.7
c	5.3	5.3	4.5–7.0
V, %	49.0		44.0–54.0