Paramphimonhystrella, Huang & Zhang, 2006

Huang, Y. & Zhang, Z. N., 2006, A new genus and three new species of free-living marine nematodes from the Yellow Sea, China, Journal of Natural History 40 (1 - 2), pp. 5-16 : 8-12

Family XYALIDAE Chitwood, 1951

Genus Paramphimonhystrella gen. nov. Paramphimonhystrella minor sp. nov. (Tables III, IV; Figures 4 , 5 )

Type material

Three males and three females collected from Stations 12494 and 11594 ( Figure 1 ). Holotype: „ 1 (ZB030195) slide number ZB030115414, Station 12494. Paratypes: two males (ZB030196–97) ZB0301122142, Station 11594 and two females (ZB030198–99) ZB0301122142 and ZB030115414, Station 11594 and 12494 .

Type locality

Benthic in the Yellow Sea. Station 12494: 33 ° 59.769N, 122 ° 59.859E, 68 m, MdØ 7.54, organic matter 2.78%; Station 11594: 34 ° 29.749N, 122 ° 30.219E, 63 m, MdØ 6.01, organic matter 2.02 %.

Etymology

This species is named for the small body.

Description Body length 740–792 mm; maximum body diameter 13–16 mm. Cuticular striation not

observed. Head attenuated. Buccal cavity deep, conical, and strongly cuticularized. Ten cephalic setae, about 2 mm long. Two groups of eight cervical setae each, first group at the level of the amphids, 3–4 mm long; the second group of setae 7–8 mm long. Amphids circular, diameter about 5 mm and 0.5–0.58 corresponding body diameter wide; about 12 mm from the head end. Tail 110–160 mm long, conico-cylindrical. Conical part about

half of tail length; anal diameter 10–13 mm. Two large obvious caudal glands. Three terminal caudal setae, 2–3 mm long.

Male. Spicules 12–13 mm long, slender with sharp tip. Gubernaculum and precloacal supplement absent.

Female. A single anterior ovary; vulva at about 61–63% of body length.

Diagnosis and discussion

Paramphimonhystrella minor sp. nov. is characterized by its small body (shorter than 800 mm), circular amphids. It is close to Paramphimonhystrella elegans sp. nov. in the structure of the buccal cavity, but differs in body size and in the shape of the amphids. It is similar to Paramphimonhystrella sinica sp. nov. in the shape of the amphids, but the principal differences between the two species are the buccal cavity and the head structure. In species of Paramphimonhystrella sinica sp. nov. the head is extended and buccal cavity is wider.

Figures

Figure 1. Map of distributed stations of new species in the Yellow Sea.

Figure 4. Paramphimonhystrella minor sp. nov. (A) Lateral view of female body, showing position of vulva; (B) lateral view of male head end, showing buccal cavity amphid and cervical setae; (C) lateral view of male tail, showing spicule and caudal glands; (D) lateral view of male anterior region, showing a cylindrical oesophagus; (E) lateral view of femal tail, showing three caudal glands.

Figure 5. Paramphimonhystrella minor sp. nov. (A, B) Lateral view of male head end, showing buccal cavity, amphid, and cervical setae; (C) lateral view of male tail, showing spicule and caudal glands.