Sabatieria cosmonautae, Fu & Mou & Liu & Zhang & Lin, 2025

Fu, Sujing, Mou, Jianfeng, Liu, Kun, Zhang, Shuyi & Lin, Heshan, 2025, Two new species and a new record of Comesomatidae (Nematoda, Araeolaimida) from the Southern Ocean, ZooKeys 1244, pp. 121-145 : 121-145

publication ID

https://doi.org/10.3897/zookeys.1244.135491

publication LSID

lsid:zoobank.org:pub:9A27507B-1DEE-4D54-82BA-4D458730E7C5

DOI

https://doi.org/10.5281/zenodo.15839129

persistent identifier

https://treatment.plazi.org/id/07A15E44-0C79-530F-B4F9-CC26CB4A8587

treatment provided by

ZooKeys by Pensoft

scientific name

Sabatieria cosmonautae
status

sp. nov.

Sabatieria cosmonautae sp. nov.

Figs 2 View Figure 2 , 3 View Figure 3 , 4 View Figure 4 , 5 View Figure 5 , Table 2 View Table 2

Material examined.

Holotype: • male, collected in the Cosmonauts Sea ; 67.1217°S, 44.3743°E; depth 1321 m; collected on 22 Jan. 2021; Jianfeng Mou leg.; total organic carbon 0.22 %; sand, 50.73 %; clay, 7.62 %; silt 41.11 %; mean particle diameter 4.49 mm; on slide no. MBSMCOIA -C 4-12-0-1-2 GoogleMaps . Paratypes: • four males and three females, collected in the Cosmonauts Sea ; 65.3262°S – 67.1217°S, 44.3743°E – 49.9987°E; depth 1321–2444 m; collected on 18 Jan. 2021 – 22 Jan. 2021, Feb. 2022; Jianfeng Mou leg.; total organic carbon 0.22 % – 0.61 %; sand, 4.78 % – 50.73 %; clay, 7.62 % – 23.70 %; silt, 41.11 % – 71.51 %; mean particle diameter 4.49–6.77 mm; males on slide no. MBSMCOIA -C 5-7-0-2-2 , MBSMCOIA -C 4-10-0-2-2 , MBSMCOIA -C 4-11-2-4 and MBSMCOIA -C 4-12-0-1 ; females on slide no. MBSMCOIA -C 4-11-2-4 GoogleMaps .

Measurements.

All measurement data are given in Table 2 View Table 2 .

Description.

Male. Body short, narrowing gradually towards both extremities. Cuticle with transverse rows of punctations starting from amphid to near tail tip. Lateral differentiation with slightly sparse punctations. Cuticle striations distinct on cuticle surface using SEM (Fig. 5 View Figure 5 ). Short somatic setae sparsely present on entire body, ~ 2 μm long. Cephalic region with distinct constriction at level of cephalic setae. Anterior sensilla in three crowns: six small inner labial papillae, six outer labial setae (2 μm long), and four cephalic setae (3 μm long or 0.15–0.25 corresponding body diameter long). Anterior buccal cavity cup-shaped, 5–6 μm wide, posterior portion narrow. Spiral amphidial fovea with three turns, 10–12 μm in diameter or 54–68 % of corresponding body diameter, anterior border located at the level of cephalic setae. Pharynx surrounds half of anterior buccal cavity, gradually broadening posteriorly and forming a weak posterior bulb. Nerve ring situated at 39–56 % of anterior pharynx. Secretory-excretory gland located posterior to pharynx. Secretory-excretory pore located posterior to nerve ring, 126–162 μm from the anterior end. Cardia small, completely surrounded by intestinal tissue. Reproductive system diorchic, anterior outstretched testis to the left of intestine and posterior outstretched testis to the right of the intestine. Spicules arcuate, equal, 1.2–1.5 cloacal body diameters long, proximal part of spicule with central cuticularized projection (lamella) extending from proximal end to approximately half of spicule. Gubernaculum with straight dorso-caudally directed apophyses. One precloacal seta 2 μm long. Sixteen or seventeen precloacal supplements, in the form of small pores, with distance between the anterior eight supplements (12–21 μm) irregularly distributed, posterior eight supplements with distance between adjacent supplements (5–13 μm) increasing towards anterior (Fig. 3 D View Figure 3 ). Conico-cylindrical tail 1.9–2.4 cloacal body diameters long bearing three terminal setae, with very slightly swollen tip. Cylindrical part ~ 1 / 5 of total tail length. Three caudal glands present. Spinneret present.

Female. Similar to males. Reproductive system with two opposed, outstretched ovaries, with anterior ovary to the left of intestine and posterior ovary to the right of intestine. Spermatheca present. Vulva at 49–50 % of body length from anterior. Granular vaginal glands present. Three caudal glands present.

Diagnosis and relationships.

Sabatieria cosmonautae sp. nov. is characterized by body length 1786–2230 μm, short cephalic setae, 0.15–0.25 corresponding body diameter long; cuticle with transverse rows of punctations starting from amphid to near tail tip; lateral differentiation with sparse punctations; spiral amphidial fovea with three turns; males with arcuate spicules, 1.2–1.5 cloacal body diameters long, straight dorso-caudally directed gubernacular apophyses, and with 16 or 17 precloacal supplements, in the form of small pores; Conico-cylindrical tail 1.9–2.4 cloacal body diameters long in males and 2.4–2.6 cloacal body diameters long in females.

Sabatieria cosmonautae sp. nov. belongs to the praedatrix group: amphids with three turns, the presence of straight gubernacular apophyses and with 16 or 17 pore-like precloacal supplements. There are 50 valid species in this group. Within the praedatrix group, S. cosmonautae sp. nov. most closely resembles S. ancudiana Wieser, 1954 , S. granifer Wieser, 1954 , S. intermissa Wieser, 1954 , S. lawsi Platt, 1983 , S. parabyssalis Wieser, 1954 as well as S. praedatrix de Man, 1907 , which are all characterized by having nearly 17 precloacal supplements. In addition, the new species differs from S. ancudiana in the stouter body shape (a = 27–35 vs 42–65 in S. ancudiana ), shorter cephalic setae (0.15–0.25 vs 0.60–0.70 cbd in S. ancudiana ) and shorter tail (1.9–2.4 vs 3.5 cloacal body diameters in S. ancudiana ), from S. granifer in the shorter tail (1.9–2.4 vs 3.3–4.8 cloacal body diameters in S. granifer ), from S. intermissa in the stouter body shape (a = 27–35 vs 40–48 in S. intermissa ), shorter cephalic setae (0.15–0.25 vs 0.70–0.90 cbd in S. intermissa ), shorter spicules (1.2–1.5 vs 2.0 cloacal body diameters in S. intermissa ) and shorter tail (1.9–2.4 vs 3.5 cloacal body diameters in S. intermissa ), from S. lawsi in the shorter tail (1.9–2.4 vs 3.1–3.8 cloacal body diameters in S. lawsi ), from S. parabyssalis in the shorter cephalic setae (0.15–0.25 vs 0.70 cbd in S. parabyssalis ), and shorter tail (1.9–2.4 vs 3.8–4.3 cloacal body diameters in S. parabyssalis ), and from S. praedatrix in the much shorter tail (1.9–2.4 vs 4.0–4.5 cloacal body diameters in S. praedatrix ).

This new species is also similar to S. bathycopia Leduc, 2013 in the celtica group by the relative cephalic setae length, relative spicule length and the value of c'. The new species differs from S. bathycopia by the value of c' (1.9–2.4 vs 3.6–4.3 in S. bathycopia ), the structure of spicules (without velum or swollen distal portion vs with velum and swollen distal portion in S. bathycopia ), and the gubernaculum shape (straight vs curved in S. bathycopia ).

Etymology.

This species is named after the type locality belonging to the Cosmonauts Sea.

Kingdom

Animalia

Phylum

Nematoda

Class

Chromadorea

Order

Araeolaimida

Family

Comesomatidae

SubFamily

Sabatieriinae

Genus

Sabatieria