Bendiella thalassa, Leduc, 2013

Leduc, Daniel, 2013, Two new genera and five new species of Selachinematidae (Nematoda, Chromadorida) from the continental slope of New Zealand, European Journal of Taxonomy 63, pp. 1-32 : 27-29

Bendiella thalassa gen. et sp. nov.

Figs. 14-16 , Table 2

urn:lsid:zoobank.org:act:31AB5540-964C-41F2-B592-F329369969DC

Diagnosis

Bendiella thalassa gen. et sp. nov. is characterised by amphideal fovea with 5.25 turns, anterior buccal cavity with twelve rhabdions, each with a pair of pointed projections at posterior extremity, posterior buccal cavity with three Y-shaped pairs of slender rhabdions fused from two thirds of distance from

anterior ends, spicules 1.4 abd, gubernaculum consisting of two detached lateral pieces (crurae) without median portion (corpus or cuneus), and conico-cylindrical tail, 7.0 abd long.

Etymology

The species name is derived from the Greek word thalassa (= sea).

Material examined

Holotype

NEW ZEALAND: ♂, NIWA 88365 , 6 Apr. 2007, NIWA cruise TAN0705, station 45, southern flank of Chatham Rise, 44.4864° S, 177.1407° E, 1238 m, silt/clay (93.9%).

Paratypes

NEW ZEALAND: 1 ♂, 3 ♀♀, NIWA 88366, 4 Jun. 2007, NIWA cruise TAN0707, station 98, eastern Challenger Plateau, 40.1264° S, 170.2217° E, 804 m, silt/clay (83.3%), very fine sand (6.6%).

Description

Males

Body cylindrical, tapering slightly towards anterior extremity. Cuticle ~ 1.5 μm thick, with transverse rows of punctations, lateral differentiation beginning ~ 1.0 cbd posterior to amphid and ending at level of cloaca, consisting of three longitudinal rows of slightly larger dots ( Fig. 16A ). Somatic setae short and sparse, irregularly spaced. Head blunt, rounded, not set off. Inner labial papillae minute; six small outer labial setae situated in same circle as four slightly longer cephalic setae, <0.1 cbd. Amphideal fovea multispiral with 5.25 turns, situated ~ 0.5 cbd from anterior extremity. Buccal cavity large, divided into anterior and posterior portions. Anterior portion of buccal cavity cylindrical to funnel-shaped, with twelve cuticularised rhabdions, each with one pair of pointed projections at posterior extremity ( Fig. 16B, C ). Posterior buccal cavity narrower, cylindrical, surrounded by three Y-shaped pairs of slender rhabdions fused from two thirds of distance from anterior ends ( Fig. 16C ). Pharynx without anterior bulb; pharynx widens posteriorly but not forming true posterior bulb. Nerve ring at ~ 40% of pharynx length from anterior. Secretory-excretory (S-E) system present, cellular body of ventral gland small, situated at posterior end of pharynx, pore situated ~ 0.6 cbd posterior to nerve ring. Intestine cells with numerous round inclusions, some cells differentiated by presence of more numerous and closely packed inclusions ( Fig. 15 ).

Reproductive system diorchic with short, ~ 40-45 μm long, outsretched testes. Anterior testis on right of intestine, posterior testis on left of intestine; small, round sperm cells, 2 μm in diameter. Spicules paired, 1.4 abd long, curved, tapering distally. Gubernaculum consisting of two detached lateral pieces (crurae) tapering distally; median portion of gubernaculum (corpus and cuneus) apparently absent. Precloacal supplements and seta absent. Two round hypodermal glands situated laterally at level of cloaca, each connected to short seta. Tail 7.0 abd long, conico-cylindrical, with short, sparse setae and pointed extremity. Three caudal glands and spinneret present.

Females

Similar to male, but with slightly smaller amphid situated 1.0 cbd from anterior extremity. Reproductive system didelphic-amphidelphic, with reflected ovaries. Anterior ovary on left of intestine, posterior ovary on right of intestine. Vulva located slightly pre-median. Pars proximalis vaginae surrounded by constrictor muscle, vaginal glands not observed. Anus not observed.

Figures

Fig. 14. Bendiella thalassa gen. et sp. nov. A. Surface view of male head. B. Surface view of female head. C. Female head, showing buccal cavity. D. Posterior body region of male. E. Spicule and gubernaculum. F. Posterior body region of female. G. Anterior body region of male. Arrow shows position of lateral hypodermal gland near posterior end of intestine. Scale bar: A-C, G = 25 μm; D, F = 32 μm; E = 13 μm.

Fig. 15. Bendiella thalassa gen. et sp. nov. A. Entire male. B. Entire female. Scale bar = 50 μm.

Fig. 16. Bendiella thalassa gen. et sp. nov. Light micrographs. A. Lateral view of male cuticle. B. Female head, showing shape of buccal cavity. C. Female head, showing details of rhabdions in anterior and posterior buccal cavity. Scale bar = 10 μm.