Pseudosteineria longisetis, Cidreira & Venekey & De Souza Alves & Kelmo, 2020

Cidreira, Gabriel, Venekey, Virág, De Souza Alves, Orane F. & Kelmo, Francisco, 2020, Description of Pseudosteineria longisetis sp. n. from northeastern Brazil with a review of the genus Pseudosteineria Wieser, 1956 (Nematoda: Xyalidae), Zootaxa 4763 (3), pp. 354-370 : 357-360

publication ID	https://doi.org/ 10.11646/zootaxa.4763.3.2
publication LSID	urn:lsid:zoobank.org:pub:C80E006C-BCEB-4681-9065-12C20820B307
DOI	https://doi.org/10.5281/zenodo.3805817
persistent identifier	https://treatment.plazi.org/id/ED8F1C37-9075-4F14-9B39-88B89ECE1BC7
taxon LSID	lsid:zoobank.org:act:ED8F1C37-9075-4F14-9B39-88B89ECE1BC7
treatment provided by	Carolina
scientific name	Pseudosteineria longisetis
status	sp. nov.

Treatment

Pseudosteineria longisetis sp. n.

( Figs. 2–5 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 ; Table 1 View TABLE 1 )

Type material. Holotype male ( MNRJ-NEMA385 ); paratypes: 4 males ( MNRJ-NEMA387 , MPEG. NEM000244 , UFBA1416 , UFBA1417 ), 5 females ( MNRJ-NEMA386 , MNRJ-NEMA388 , MPEG. NEM000245 , UFBA1418 , UFBA1419 ) and 3 juveniles ( MNRJ-NEMA389 , MPEG. NEM000246 , UFBA1420 ).

Type locality and habitat. Intertidal sandy sediment from Armação Beach, Salvador, Bahia, Brazil (12°59’43.5”S, 38°26’24”W) ( Fig. 1 View FIGURE 1 ). Beach about 3 kilometers long, sediment composed of medium to coarse sized sand grains; humid tropical climate with high rainfall, with April and May being the months of highest rainfall ( Farias et al. 1985). Pseudosteineria longisetis sp. n. was found in the three strata collected.

Etymology. The specific epithet refers to the long somatic setae that are one of the diagnostic characters of Pseudosteineria longisetis sp. n.

Description. Holotype and paratype males. Body spindle-shaped, 1213 μm long (1186–1281 μm) ( Figs. 2A View FIGURE 2 and 3A View FIGURE 3 ). Cuticle distinctly annulated, beginning at base of buccal cavity and ending at tail tip. No distinct lateral field in cuticle. Lip region set off. Six lips slightly inflated. Anterior sensilla arranged in two circles, anterior one with six inner labial papillae and posterior with 12 sensilla, six longer outer labial setae, four shorter cephalic setae, and two additional lateral setae.

Long subcephalic (cervical) setae arranged in six short longitudinal rows, subdorsal, sublateral and subventral on both sides of body, located posteriorly to cephalic setae, 19–20 μm from anterior end (16–20 μm) ( Figs. 2 View FIGURE 2 A–B and 3A–C). Two subventral groups with five setae, two sublateral groups with four setae, and two subdorsal groups with three setae. Length increases gradually from anterior to posterior setae in every row. Length of shortest subcephalic seta measuring 26 μm (24–27 μm), longest is 118 μm (76–118 μm). Somatic setae variable in length, being short or very long (up to 4x body diameter), distributed along body, longest about 116 μm (91–130 μm). Somatic setae more abundant ventrally ( Figs. 2A View FIGURE 2 , 3 View FIGURE 3 A–B).

Buccal cavity with hemispherical cheilostome and conical pharyngostom, surrounded by pharyngeal tissue. Amphideal fovea relatively small, circular, 5 μm in diameter (4–5 μm), 24% of corresponding body diameter (20– 24%), situated slightly anterior to groups of subcephalic setae or at level of first subcephalic setae ( Figs. 2 View FIGURE 2 A–B and 3C). Pharynx cylindrical and muscular throughout its length. Pharyngo-intestinal junction with cardia. Nerve ring at 95 μm from anterior end (94–104 μm).

Two testes, anterior one outstretched and situated on left side of intestine, posterior one reflexed and on right side of intestine. Spicules paired, slender, equal in length, curved, and 35 μm along arc (27–35 μm) ( Figs. 2 View FIGURE 2 C–D and 3D). Distal extremity of spicules with circular orifice in middle and tip with two small pointed structures. Gubernaculum as a membranous sheath, with dorso-caudal apophysis, 18 μm long (17–21 μm) ( Figs. 2 View FIGURE 2 C–D and 3D). One small precloacal papiliform supplement at 11 μm from cloaca (11–14 μm) ( Figs. 2C View FIGURE 2 and 3D View FIGURE 3 ). Tail conico-cylin- drical, 208 μm long (192–208 μm), 6.9 anal body diameters (6–7.2). Length of posterior cylindrical portion of tail equals to 43% (37–43%) of the entire tail. Three caudal glands and tail tip with two pairs of terminal setae, 30–31 μm long (24–33 μm) ( Figs. 2A, 2C View FIGURE 2 , 3A, and 3E View FIGURE 3 ).

Paratype females. Similar to males in most morphological characters, except for presence of six subcephalic setae instead of five in the subventral groups of some individuals, tail slightly longer than in males, 209–233 μm long, and one pair of terminal setae instead of two, 21–49 μm long. Reproductive system monodelphic, with a single anterior outstretched ovary on left side of intestine. An egg present in uterus of paratype MNRJ-NEMA386. Vulva located at about 62–63% of body length from anterior end, 713–858 μm from anterior end ( Figs. 4A View FIGURE 4 , 5A, 5D, and 5E View FIGURE 5 ).

Juveniles. Similar to adults, except for smaller measurements of morphological characters, absence of precloacal supplement, and reproductive system immature. Some individuals lack some subcephalic setae.