Campylaimus pulcher, 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 : 233-236

Campylaimus pulcher sp. nov.

( Figs. 7 , 8 )

Locality: Table 1 .

Measurements. Table 5 .

Material examined. Holotype. Adult male, formalin-fixed, mounted on slide (MN A251-3), in glycerin. Allotype. Adult female, formalin-fixed, mounted on slide (MN A362-2), in glycerin. Paratype. Male, slides (AA362-2) same data as allotype.

Etymology. The species name is derived from the Latin “ pulcher ” meaning “noble, beautiful”.

Description. Males. Plump nematodes (a = 18–19) with distinct annulation (each annule 2.0 µm in height), extending along entire body. Anterior end with a clearly visible cuticular cap ( Fig. 7 ). Oral opening located subterminally, on dorsal side of body. Buccal cavity unarmed. Four short (2 µm) cephalic setae asymmetrically placed: latero-dorsal pair of short setae located a little posterior to latero-ventral pair. Amphids comprising an elongate loop with almost equal parallel limbs connected behind the oral opening, amphidial fovea 2.6 µm wide. Prominent narrow longitudinal alae (1.5–2 µm) extending along body to posterior end; arising from ventral limb of amphid ( Fig. 7 ). Amphidial glands large, prominent, situated 120 µm from anterior end of body. Significant secretory discharge visible around amphids.

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

Male reproductive system diorchic, both testes short, outstretched, opposed. Spicules equal in length, curved, cephalated at proximal end. Gubernaculum absent. Short conical tail, 103–115µm long (4.1-3 a.b.d), gradually tapering toward the distal end, tip swollen ( Fig. 7 ).

Females similar to male. Gonads paired, opposed; ovaries outstretched, not reflexed. Anterior and posterior ovaries located on the left and right side of intestine, respectively. Vulval orifice ventral, located in anterior part of body (V = 48%). Vagina short, not thickened. Two glands surround the vulva.

Diagnosis. The distinctive feature of C. pulcher sp. nov. is the elongate loop-shaped amphid with almost equal parallel limbs with invisible gap, prominent narrow longitudinal alae and cephalated proximal spicules without gubernaculum.

Differential diagnosis. In amphid structure, C. pulcher sp. nov. is similar to four congeners: C. cylindricus , С. abditus , C. minor , and C. orientalis sp. nov..

The specimens of C. pulcher sp. nov. differ from C. cylindricus (described only from females) by having a shorter (690–755 µm vs 1095 µm in C. cylindricus ) and broader body (a = 19 vs 31, respectively), and a shorter amphid (32–37 µm vs 48 µm). The new species differs from С. abditus by the presence of the prominent narrow longitudinal alae (vs absent in C. abditus ), absence of the gubernaculum (vs present in C. abditus ) and relatively longer tail (c = 6.6–6.9 vs 9.1). Campylaimus pulcher sp. nov. differs from C. minor (described only from females) by the size of the body (690 µm vs 384 µm) and by having a relatively shorter tail (4.3 a.b.d. vs 5 a.b.d.). The new species differs from C. orientalis sp. nov. in numerous respects, including the amphid shape (ventral and dorsal parallel limbs without space between them vs space about 2 µm between them in C. orientalis ) and in the absence of two pairs of small postcloacal setae (vs present in C. orientalis sp. nov.).

Figures

FIGURE 7. Campylaimus pulcher sp. nov. Male holotype. A: Entire body; B: Spicule; C: Posterior end. Scale bar: A = 100 µm; B = 20 µm; C = 25 µm.

FIGURE 8. Campylaimus pulcher sp. nov. Female allotype. A: Entire body; B: Amphidial fovea on anterior end; C: Posterior end. Scale bar: A = 50 µm; B, C = 20 µm.

Tables

TABLE 5. Measurements (Μm) of Campylaimus pulcher sp. nov.

	HOLOTYPE	ALLOTYPE	PARATYPE
	Male	Female N=1	Male N=1
L	707.7	690.0	755.4
Maximum body diameter	38.4	36.0	42.0
Buccal cavity, length	4.0	4.0	4.0
Head diameter	9.0	9.0	9.0
Cephalic setae, length	2.0	2.0	2.0
Dorsal limb of amph. fovea length	29.0	32.4	25.0
Ventral limb of amph. fovea length	35.9	37.7	45.0
Amphidial fovea width	2.6	2.6	2.6
Lateral alae	2.0	2.0	2.0
Pharynx, length	116.8	110.0	120.0
Tail, length	103.0	130.0	115.0
Spicular, length	26.2	-	25.0
Anal body diameter	25.0	23.0	23.0
a	18.4	19.2	17.9
b c V,%	6.0 6.9	6.3 6.9 48.0	6.3 6.6