Setosabatieria major, Guo & Huang & Chen & Wang & Lin, 2015

Guo, Y. Q., Huang, D. Y., Chen, Y. Z., Wang, J. J. & Lin, R. C., 2015, Two new free-living nematode species of Setosabatieria (Comesomatidea) from the East China Sea and the Chukchi Sea, Journal of Natural History 49 (33), pp. 2021-2033 : 2026-2030

Setosabatieria major sp. nov. ( Figures 3, 4 and Table 2)

Type material

Five males, one female and one juvenile from station CC4 . Holotype: ♂ 1 on slide number Chukchi20100720 CC42401 .

Paratypes: ♂ 2 on slide number Chukchi20100720 CC42401 , ♂ 3 on Chukchi20100720 CC42403 , ♂ 4 on Chukchi20100720 CC42404 , ♂ 5 on Chukchi20100720 CC42405 , ♀ 1 on Chukchi20100720 CC42406 , juvenile on Chukchi20100720 CC42407 .

Type locality and habitat

Sublittoral zone in the Chukchi Sea (the Arctic Ocean). Latitude: 68.1336°N, longitude: 167.8633°W.

Environmental parameters: water depth 52 m, surface water temperature 2.2°C, salinity at 52 m depth 32.13 ‰.

Etymology

This species is named for the large body.

Measurements

Measurements are given in Table 2.

– 366 W 2806

Holotype ♂ 1: 3130 µm; a = 18.6, b = 8.6, c = 9.7, Spic = 69 µm

21 117 168 82

– 332 V 2828

Paratype ♀ 1: 3145 µm; a = 17.9, b = 9.5, c = 8.0, V % = 44.1%

23 104 176 80

Description

Body rather large cylindrical, tapering towards both extremities. Cuticle not punctated but with transverse striation most obvious at anterior and posterior extremities. Buccal cavity small cup-shaped, surrounded by six short outer labial, 1.5 – 2 μm long and four cephalic setae, 9 – 13 μm long. Amphidial fovea spiral, with 3.25 – 3.75 turns and occupying 47 – 57% of corresponding body diameter. Four sublateral rows of 10 – 11 cervical setae 8 – 10 μm long. Pharynx gradually swollen posteriorly, not forming a true bulb. Cardia small, muscular, surrounded by intestinal tissue. Ventral gland situated posterior to pharynx and excretory pore about level nerve ring. Nerve ring at 55 – 61% of pharynx length from anterior end. Tail slender, with rather broad, conical anterior portion and rather narrow cylindrical posterior portion. Tail 3.7 – 4.5 times of the anal body diameter with numerous short setae. Tail tip not enlarged, with 15 µm long three terminal setae. Caudal glands not always visible and spinneret well developed.

Males. Reproductive system with two opposite outstretched testes. Spicules paired, equal, slight arcuate, 0.9 – 1.3 times as long as cloacal body diameter, with central septum appearing in both proximal and distal portions. Gubernaculum with a pair of short dorsocaudal apophyses. There are 26 – 28 small pre-cloacal papillae supplements, although they are very small and difficult to observe.

Females. Similar to male in general characteristics, but tail with fewer short setae and narrow cylindrical posterior portion longer than anterior conical portion. Reproductive system with two outstretched equally developed ovaries. Vulva at 44% of total body length.

Differential diagnosis

Setosabatieria major sp. nov. is characterized by its rather large body (length 2700 – 3145 µm; maximum body diameter 106 – 176 µm), the number (10 – 11) of cervical setae per file, 26 – 28 small papillate precloacal supplements and central septum appearing in both proximal and distal portions of spicules. These characters are obviously different from those of other species in this genus.

Figures

Figure 4. Setosabatieria major sp. nov. (A) lateral view of male head end, showing cervical setae; (B) lateral view of female head end, showing female amphidial fovea; (C) lateral view of female vulva region, showing vulva and eggs; (D) lateral view of male tail region. Scale bars: A = 25 µm; B = 10 µm; C, D = 50 µm.