Litinium australis Martelli, Russo, Villares & Ward, 2017, sp. n

Autor: Martelli, Antonela, Russo, Virginia Lo, Villares, Gabriela, Pastor De Ward, Catalina T.
Rok vydání: 2017
Předmět:
DOI: 10.5281/zenodo.5623730
Popis: Litinium australis sp. n. (Figures 2 & 4 (A���C); Table 1) Systematic position. Oxystominidae Chitwood, 1935: Oxystomininae Chitwood, 1935: Litinium Cobb, 1920 Type material. Holotype: adult male. Registration number CNP-NEM 1528; type locality: San Jos�� gulf; coordinates: 42��21���S, 64��08���W; sublittoral, mud sediments (59.8 m water depth). Collected by C.T. Pastor de Ward, 22 August 1984. Paratype: adult female. Registration number CNP-NEM 1529. Same data as holotype. Other material: One male and one juvenile. Registration number MACN-In 40898. Same data as holotype. Etymology. In reference to the name of the sailboat, El Austral, with which the sample was collected. Measurements. See Table 1. Description. Male (holotype): Cylindrical body, tapering slightly towards the anterior end (L = 2495 ��m). Cuticle smooth. Somatic setae not seen. Buccal cavity small and narrow. Cephalic sensilla present in 6 + 6 + 4 circles. Six inner labial setae, 3.2 ��m long, and six outer labial setae, 4 ��m long. A crown of four cephalic setae (4 ��m in length) at 2 c.d. from anterior end. Amphid and amphidial pouch conspicuous, situated 4 ��m from anterior end. Amphidial fovea 6 ��m wide and 9 ��m long. Cephalic diameter 11 ��m at level of amphid. Amphid width about 55% of the corresponding head diameter. Excretory pore located at 31 ��m (3.9 c.d.) from anterior end. Pharynx cylindrical (315 ��m long), ending in a small weakly-developed bulb (18 ��m in diameter). Body diameter at the base of pharynx 27 ��m. Reproductive system diorchic, testes opposed. Anterior and posterior testes situated to the left of the intestine. Spicules equal in length, 34 ��m long, arcuate and cephalated (1.6 abd). Gubernaculum tubular, corpus 13 ��m long, with apophysis, and capitulum 5 ��m long. At least four precloacal organs observed, with one seta in each. The two closest to the cloaca are more conspicuous and the others are tiny. The first precloacal organ lies 32 ��m anterior to the cloaca and has a seta 3 ��m long. The other precloacal organs are 93 ��m, 120 ��m and 202 ��m from the cloaca, each one with a 3 ��m long seta. Tail short and round, 29 ��m long, without caudal capsule. Female (paratype): Female larger (L = 3455 ��m) but similar to male in general body shape. One posterior ovary located on the right side of intestine, antidromously reflexed. Vulval orifice ventral, located at 20% of body length. Uterus and oviduct 2675 ��m long and the antidromously reflexed ovary 200 ��m in length. Vagina short and not thickened. Differential diagnosis. Litinium australis sp. n. is characterized by the first and the second crown of setae of differing lengths, rounded tail, gubernaculum with apophysis, and by the presence of four precloacal papillae. Litinium australis sp. n. resembles, in the similar shape and length of the tail (short and rounded): L. aequale, L. curticauda, L. obtusilobus, L. profundum, L. quangi, L. volutum and the recently-transferred species L. egregius, L. paramontemari, L. pirum and L. setosus. L. australis differs from L. aequale, L. curticauda, L. profundum, L. quangi, L. egregius, L. paramontemari and L. setosus in the number of precloacal organs. L. pirum and L. volutum have as many precloacal organs as L. australis, which differs from these species, and from L. obtusilobus, in amphid shape and size and in length of the inner and outer labial setae.
Published as part of Martelli, Antonela, Russo, Virginia Lo, Villares, Gabriela & Pastor De Ward, Catalina T., 2017, Two new species of free-living marine nematodes of the family Oxystominidae Chitwood, 1935 (Enoplida) with a review of the genus Thalassoalaimus de Man, 1893 from the Argentine coast, pp. 347-357 in Zootaxa 4250 (4) on pages 350-352, DOI: 10.11646/zootaxa.4250.4.5, http://zenodo.org/record/495299
{"references":["Chitwood, B. G. (1935) Nomenclatorial Notes, I. Proceedings of the Helminthological Society, Washington, 2, 51 - 54.","Cobb, N. A. (1920) One hundred new nemas (Type species of 100 new genera). In: Contributions to a science of nematology. Williams & Wilkins, Baltimore, pp. 217 - 343."]}
Databáze: OpenAIRE
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