Syringolaimus magdae, Coelho Lima, Lins, Da Silva & Esteves, 2009

Lima, Rita De Cássia Coelho, Lins, Lidia, Silva, Maria Cristina Da & Esteves, André Morgado, 2009, Four new species of Syringolaimus De Man, 1888 (Nematoda: Ironidae) from the Southeast Atlantic (Brazil), with redefinition of valid species and the proposal of a new key *, Zootaxa 2096, pp. 119-136 : 125

Syringolaimus magdae sp. n. ( Figs. 3 and 4)

Type material: One male collected from station 84 (Appendix). Holotype ♂ 1: slide number MNRJ 332 station 84.

Type locality: Campos Basin (Rio de Janeiro, Brazil), found at 1050 m depth, in silt-clay sediments in the layer of 2–5 centimeters .

Etymology. The species epithet honors Professor Magda Vincx from Ghent University, Belgium.

Description. Measurements: Holotype ♂ 1: L: 1674; hd: 11.4; amph wid: 6.6; cbd: 15; amph (%): 44; amph dist: 10.2; buc cav l: 50.4; ph: 234.7; buc cav 1/ph (%): 21.5; nr/ph (%): 56.2; ex pore/ph (%): 35.2; bulb l: 48.3; bulb l /ph (%): 20.6; bulb d: 23.4; cbd: 29.4; bulb (%): 79.6; mbd: 33; abd: 25.5; t: 153; con/t (%): 35; cil/t (%): 65; spin: 32.4; spin/t (%): 21.2 spic: 31.5; gub: 11.4; a: 51; b: 7.1; c: 11; c’: 6.0.

Male Holotype: Body 1674 µm long, maximum diameter 33 µm. Striations not easily observed. Outer labial papillae present. Head diameter 11.4 µ m. Amphideal phovea pocket-like, occupying 44% of corresponding body diameter. Buccal cavity cylindrical, sclerotized and deep, 50.4 µm long corresponding to 21.5% of pharynx. Three bifid asymmetrical teeth of equal size, one dorsal and two subventral. Pharynx muscular, slightly dilated in base of buccal cavity, and with elongated basal bulb 48.3 µm long, occupying 79.6% of corresponding body diameter. Secretory-excretory pore situated 35.2% from anterior end. Nerve ring placed posterior to mid-pharynx (56.2%). Rounded cardia. Ventral gland placed slightly posterior to cardia. Testis lying on right side of intestine. Anterior portion of testis with well-marked glandular portion. Short deferent duct with sperm cells in beginning of duct. Sperm cells fusiform. Two ejaculatory glands anterior to spicule. Spicule 31.5 µm long, arch-shaped, with dorsal region hook-shaped and containing strongly sclerotized punctuations. Gubernaculum slender (11.4 µm). Tail conical-cylindrical, with spinneret; the cylindrical portion comprises 65% of tail length. Spinneret long and sharp (32.4 µm), beginning in a dilated region and corresponding to 21.2% of tail length. Three caudal glands present.

Diagnosis. The presence of one pair of pre-cloacal ejaculatory glands and a large pointed spinneret, corresponding to 21.2% of the tail length, are the main features that characterize this new species.

Relationships. S. magdae sp. n. resembles S. filicaudatus due to the presence of labial papillae, absence of cephalic sensilla, base of the buccal cavity dilated, and bifid teeth. However, the tail of the new species does not have a filiform portion, and the spinneret is relatively longer (21.2%). The index c of De Man indicates a smaller tail in S. magdae sp. n. (c–11) than in S. filicaudatus (c–5). The conical portion of the tail also has different proportions in the two species, 35% in S. magdae sp. n. and 20% in S. filicaudatu s.