Deontolaimus mangrovi, Tu, Nguyen Dinh, Thanh, Nguyen Vu, Hoang, Lai Phu & Saint-Paul, Ulrich, 2016

Tu, Nguyen Dinh, Thanh, Nguyen Vu, Hoang, Lai Phu & Saint-Paul, Ulrich, 2016, Two new species of the genus Deontolaimus de Man, 1880 (Nematoda: Leptolaimidae) from mangrove ecosystems of Vietnam, Zootaxa 4205 (1), pp. 73-80 : 74

1. Deontolaimus mangrovi sp. n.

( Table 1 , Figure 1,2)

Description. Male. Body length 650 µm (478-766µm). Maximum diameter 15µm (14-16 µm). Cuticle finely annulated with longitudinal unstriated band extending from just posterior to the amphids and visible to the end of the conical region of the tail. Four cephalic setae very minute and difficult to detect, six anterior sensilla not visible. Amphids a simple spiral of one turn situated well forward between the cephalic setae, 2-3 µm width (0.5-0.6 hd). Buccal cavity with a long stylet-like tooth, 19 µm (3.3 hd) in length. Pharynx cylindrical, enlarged in the posterior one-third into an elongate bulb. Testes paired, outstretched and located on the left side of intestine. Spicules ventrally curved, 22 µm in length, measured along the chord. Gubernaculum with caudal apophysis. 32-49 simple, cup-shaped precloacal supplements. The number and arragement of supplements variesin different individuals. In specimens with 32-34 supplements, 26-27 supplements are frequently located from the anterior pharyngeal region to the middle of the body, with 6-8 remaining supplements located in the precloacal region, of which 4 supplements form a subgroup present anterior of the cloaca. In other specimens with 47-49 supplements, 42-44 supplements make up the anterior group, with only 5 supplements in the precloacal region and 3 supplements in the subgroup nearest the cloaca. However, the number of supplements in the region from the anterior part of the pharynx to the cardia is a constant 17-19 supplements. Tail 93 µm long (7.7 abd), conical for 25-30% of its length, then narrowing and elongated.

Female. Similar to male in most features. Body length 869 µm (752-920µm), much longer then in male. Maximum diameter 21 µm, a little wider than male. Ovaries pair, opposed and reflexed. Vulva at 46% (43-52%) of body length.

Remark. The new species differs from D. papillatus de Man, 1880 in tail shape: conical then elongated and end without pointed tip in D. papillatus vs with conical with pointed tip strongly cuticularised in D. cangioensis .

Type material. Holotype (1♂) adult male, slide VNMN.0048. Paratypes. 9♂♂, slides: VNMN. 0049 - 55, 6♀, slides VNMN.0059 – 64, deposited at the Vietnam National Museum of Nature , Vietnam.

Etymology. The species epithet refers to the mangrove forest where this species was found.