Stylotheristus multipapillatus Pinto & Neres 2020, sp. n.
Creators: name: Pinto, Taciana Kramer
name: Neres, Patricia Fernandes
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Nematoda
Chromadorea
Monhysterida
Xyalidae
Stylotheristus
Stylotheristus multipapillatus

description: Stylotheristus multipapillatus sp. n.
(Figures 14–17, Tables 6–7)
urn:lsid:zoobank.org:act: 150026D3-AA0D-4D1B-8421-E85A311DC209
Type material. Five males and two females were collected at station 38. Holotype (♂) MUHNAC / MB 26–000028. Paratype (♀) MUHNAC / MB26–000029. Other paratypes: UFALPEN/ LEB 0014–018
Type Locality. Sandy sediments adjacent to an artificial reef (Shipwreck) (Table 1)
Etymology. The specific epithet “ multipapillatus ” (multis - meaning many) is given because the male this species presents several precloacal papillae.
Measurements. Table 6.
Description. Male. Body cylindrical with anterior region slightly attenuated, 1920–2052 µm long. Cuticle striated. Anterior sensilla arranged according to pattern described for the genus, six papillae setiform, conical (3.5–5.5 µm), and a circle with sixteen setae: six (21–24 µm) + four (18–21 µm) + six (13–17 µm). Buccal cavity conical, with pharyngeal muscles well-developed around it. Oval amphideal fovea occupying 32–39% of corresponding body diameter; located 30.6–33 µm from anterior end (about 1 time cephalic diameter posterior). Pharynx cylindrical, muscles well-developed around the buccal cavity. Nerve ring located at 42–46% of pharynx length from anterior end. Secretory–excretory pore not observed. Only one anterior testis. Testis initially left of intestine, second third right of intestine and the last third becomes the left again. Spicules short and thin (0.6–0.9 times cloacal body diameter) and almost straight. Gubernaculum narrow, laminar, about 37–55% of spicule length. Fifteen papilliform precloacal supplements; the first (anteriormost) 126–253 µm from cloaca and the last (posteriormost) 16–29 µm from cloaca. Three caudal glands. Tail conico-cylindrical with three terminal setae (7–10 µm).
Female. Similar to male, except for cephalic sensilla arrangement, 6 conical papillae (4 µm) + ten setae, six outer labial (24–31 µm) and four cephalic setae (18.5–19 µm) in the same circle. Oval amphideal fovea occupying 29–31% of corresponding body diameter. Buccal cavity 15.5 µm long and 19–23 µm in diameter (at its middle). Ovary outstretched and on left side of intestine. Vulva located posterior to mid-body (59–63% of total body length). Spermatheca not observed, only sperm cell inside the uterus. Tail 9.6–11 times anal body diameter, with three terminal setae (7–9 µm).
Diagnosis. Stylotheristus multipapillatus sp. n. is characterized by presence of precloacal supplements (papilliform) and the narrow gubernaculum narrow formed by only one piece.
Differential diagnosis. For the genus Stylotheristus, only one species was described, S. mutilus. The new species is similar to the species already described. The main characteristic features that differentiate them are present in the male, which are: the presence of precloacal supplements and gubernaculum formed by only one piece in the new species. S. mutilus has no supplements and the gubernaculum is formed by two pieces, one directed to the anterior part of the body (anterior to the spicules) and the other to the posterior part (posterior to the spicules). Besides that, the tail in the new species is shorter than that of S. mutilus, reflected by different values of c (tail length/maximum body diameter) and c’ (tail length/anal or cloacal body diameter) (Table 7). In addition, in females of new species no spermathecae were observed, as in S. mutilus, only spermatozoa inside the uterus.
description: Published as part of Pinto, Taciana Kramer & Neres, Patricia Fernandes, 2020, Four new species of free-living nematodes from shallow continental shelf of Portugal, pp. 1-33 in Zootaxa 4722 (1) on pages 24-29, DOI: 10.11646/zootaxa.4722.1.1, http://zenodo.org/record/3603616