Odontophora sinapophysis, Pinto & Neres, 2020

Pinto, Taciana Kramer & Neres, Patricia Fernandes, 2020, Four new species of free-living nematodes from shallow continental shelf of Portugal, Zootaxa 4722 (1), pp. 1-33 : 18-23

publication ID	https://doi.org/ 10.11646/zootaxa.4722.1.1
publication LSID	lsid:zoobank.org:pub:129CE7BA-4F15-42F2-9EE2-07E8C5CD0FB4
DOI	https://doi.org/10.5281/zenodo.5585014
persistent identifier	https://treatment.plazi.org/id/A019878A-FFF3-FF58-41B3-A47C9AF3FA69
treatment provided by	Plazi
scientific name	Odontophora sinapophysis
status	sp. nov.

Treatment

Odontophora sinapophysis sp. n.

( Figures 10–13 View FIGURE 10 View FIGURE 11 View FIGURE 12 View FIGURE 13 , Table 5)

urn:lsid:zoobank.org:act:292388EA-5980-43A3-8B2B-7ABB8F693831

Type material. Five males and one female were collected at station 38. Holotype (♂) MUHNAC / MB 26–000026 . Paratype (♀) MUHNAC / MB26–000027 . Other paratypes: UFALPEN/ LEB 0010–0013 View Materials

Type locality. Sandy sediments adjacent to an artificial reef (Shipwreck) ( Table 1 View TABLE 1 )

Etymology. The specific epithet “ sinapophysis ” (sine —meaning without or lacking) is given because this species is the first to have gubernaculum without apophysis.

Measurements. Table 5.

Description. Male. Body cylindrical 4440–4950 µm long. Anterior region slightly attenuated, head diameter corresponding to 62–88% of body diameter in pharynx end. Cuticle finely striated, striations sometimes difficult to observe. Somatic setae present in pharynx region (4–8.5 µm), distributed in four rows, two lateroventral and two laterodorsal. Some caudal setae present. Anterior sensilla arranged according to the pattern 6+6+4: inner labial and outer labial papilliform, cephalic setae setiform (0.95–1.2 times corresponding body diameter). Single mediolateral subcephalic seta immediately posterior to each amphidial fovea. Other subcephalic setae present (9–12.5 µm) located near middle of funnel shaped portion of buccal cavity. Amphidial fovea loop shaped, rounded (27–39% of corresponding body diameter) located between cephalic setae and 2.5–5 µm behind anterior end. Buccal cavity separated into two portions: anterior portion with six strongly cuticularized and eversible odontia, 9–10 µm long; posterior portion funnel shaped and with cuticularized walls, 18.5–20 µm deep and 7–8.5 µm wide at anterior extremity. Cylindrical pharynx (192–200 µm or 3–4% of the total body length), posterior end slightly enlarged. Cardia completely inserted into intestine. Secretory–excretory pore not observed. Ventral gland posterior to the pharynx end. Never ring 83.4–128 µm from anterior end. Two testes left of intestine, one branch extended and one reflexed. Spicules strongly bent in their proximal third (1.2–1.34 times cloacal body diameter), cephalate proximally and distal portion rounded. Gubernaculum (12.5–14 µm) without apophyses. Precloacal supplements absent. Tail conical (4.9–6.1 times cloacal body diameter). Three caudal glands and triangular spinneret present.

Female. Largely similar to male. Cephalic setae (1.17 times corresponding body diameter). Amphidial fovea loop shaped, rounded, 31% of corresponding body diameter, located 3.5 µm behind anterior end. Two opposed outstretched ovaries, anterior branch (360 µm) left of intestine and posterior branch (432 µm) right of intestine. A mass of sperm is attached to the vulva with something like a mucosal clump. Vulva located slightly posterior to mid-body (57% of total length). Large seminal receptacle. Tail conical, slightly smaller than in male (3.6 times anal body diameter), with three caudal glands and triangular spinneret.

Diagnosis. The new species presents as main characteristics: cuticle finely striated, cephalic setae setiform about one corresponding body diameter, single mediolateral subcephalic seta immediately posterior to each amphidial fovea and other subcephalic setae at about middle region of the funnel shaped portion of the buccal cavity; amphidial fovea loop shaped, rounded, very close to the anterior end (27–39% of corresponding body diameter); spicules strongly bent in their proximal third (1.2–1.4 time cloacal body diameter), cephalate proximally and with distal portion rounded; gubernaculum without apophyses measuring 0.3 times spicule length, precloacal supplements absent, tail conical (5–6 times cloacal body diameter) in male and 3.6 times anal body diameter in female; female with large seminal receptacle.

Differential diagnosis. The new species differs from all the others already described in the genus by the absence of apophysis in the gubernaculum; therefore, an amendment in the genus diagnosis is necessary. In Leduc & Zhao (2016), the authors subdivided Odontophora species according to the position of the subcephalic setae and the spicule shape. The species described here belong to the group that has single mediolateral subcephalic seta immediately posterior to each amphidial fovea, just like O. wieseri Luc & De Coninck 1959 , O. octoseta Boucher & Helléouët 1977 and O. tenuicaudata Allgén, 1935 . However, these species possess gubernaculum with apophysis and other characteristic different from new species. O. wieseri presents cephalic setae 2 times corresponding body diameter, almost twice as long as in new species; O. octoseta present spicules strongly bent and without capitulum and O. tenuicaudata has spicules arcuate and with capitulum, while the new species has spicules L-shaped and capitulum. Females have a well-developed seminal receptacle as in O. falcifera Ott, 1972 . The accessory buccal structures in anterior portion of buccal cavity, as described in Leduc & Zhao (2016), were not observed because the odontia were retracted in the buccal cavity.

Systematics (According to De Ley et al. 2006)