XYALIDAE Chitwood, 1951

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

publication ID

http://doi.org/ 10.1080/00222930600617781

persistent identifier


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scientific name

XYALIDAE Chitwood, 1951


Family XYALIDAE Chitwood, 1951  

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

Type material

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


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.