Hystrignathus splendidus, Rodríguez & Rodríguez, 2010

Rodríguez, Jans & Rodríguez, Nayla, 2010, Two new species of nematode (Oxyurida, Hystrignathidae) parasites of Passalus interstitialis Escholtz, 1829 (Coleoptera, Passalidae) from Cuba and a new locality for Longior similis Morffe, Garcia & Ventosa, 2009, ZooKeys 49 (49), pp. 1-11 : 3-5

Hystrignathus splendidus sp. n.

urn:lsid:zoobank.org:act:981F3BC9-00E7-4B91-809A-CF741E6C366F

Figs 1 A–I, 2 A–E

Type material. ♀ holotype, Cuba, La Habana Province, Jaruco, Escaleras de Jaruco ; in Passalus interstitialis ; 16.III.2008; E. Fonseca, J. Morffe & F. Alvarez coll.; CZACC 11.4530 . 2 ♀♀ paratypes, same data as holotype, CZACC 11.4531 – 11.4532 .

Measurements. Holotype (female) a = 15.28, b = 5.85, c = 7.24, V% = 54.55, total length = 2.750, maximum body width = 0.180, stoma length = 0.063, procorpus length = 0.360, isthmus length = 0.038, diameter of basal bulb = 0.078, total length of esophagus = 0.470, nerve ring to anterior end = 0.230, excretory pore to anterior end = 0.720, vulva to posterior end = 1.250, anus to posterior end = 0.380, eggs = 0.100 –0.105 × 0.045 –0.050 (0.104 ± 0.003×0.048 ± 0.002).

Paratypes (females) (n = 2): a = 14.71–15.89 (15.30 ± 0.84), b = 5.30–5.56 (5.43 ± 0.18), c = 5.71–6.41 (6.06 ± 0.50), V% = 53.93–54.00 (53.97 ± 0.05), total length = 2.225 –2.500 (2.363 ± 0.194), maximum body width = 0.140 –0.170 (0.155 ± 0.021), stoma length = 0.053 (0.053), procorpus length = 0.310 –0.340 (0.325 ± 0.021), isthmus length = 0.035 (0.035), diameter of basal bulb = 0.068 –0.078 (0.073 ± 0.007), total length of esophagus = 0.420 –0.450 (0.435 ± 0.021), nerve ring to anterior end = 0.195 –0.250 (0.223 ± 0.039), excretory pore to anterior end = 0.560 –0.720 (0.640 ± 0.113), vulva to posterior end = 1.025 –1.150 (1.088 ± 0.088), anus to posterior end = 0.390 (0.390), eggs = 0.098 –0.108 × 0.043 –0.053 (0.104 ± 0.003×0.050 ± 0.004).

Description. Female body comparatively stout. Cuticle markedly annulated in spiny region and less in rest of body. Cervical cuticle with opposite rows of small spines, from end of first cephalic annule at or near end of procorpus. Spines arranged initially in 16 rows increasing to about 24 rows where spines cease. Longitudinal sub-cuticular striae present. Lateral alae extending from end of spiny region to level of vulva. Head bears eight papillae arranged in pairs. First cephalic annule long and inflated, about three head-lengths long and set-off from head by single groove. Stoma long, extending for about first two annule lengths and surrounded by an esophageal collar. Esophagus consisting of muscular procorpus with base slightly clavate and set-off from the isthmus. Basal bulb sub-pyriform with valve plate well developed. Intestine simple, sub-rectilinear and with its fore region inflated. Rectum short and anus not prominent. Nerve ring encircles procorpus at about its midpoint. Excretory pore situated at about one body-width posterior to basal bulb. Vulva a median transverse slit slightly displaced towards posterior half of body; lips not very prominent. Vagina muscular, forwardly directed. Genital tract didelphic-amphidelphic. Anterior ovary reflexed at about half of body-width posterior to excretory pore, with distal flexure about a body-width long. Posterior ovary shorter and not reflexed. Eggs ovoid with eight longitudinal but not very prominent ridges on shell. Tail conical, comparatively short, slightly subulate, ending in fine tip. Male unknown.

Differential diagnosis. H. splendidus sp. n. can be easily differentiated from most species of the genus by the long and inflated first cephalic annule. It shares this feature with H. tarda (Artigas, 1928) and H. inflatus Travassos & Kloss, 1957 from Brazil.

It is close to H. inflatus but differs by its ridged eggs which are shorter in length but just as wide (0.098 –0.108 × 0.043 –0.053: 0.110 –0.129 × 0.038 –0.053). Also, H. splendidus sp. n. has a comparatively stout body (a = 14.71–15.89: 19.75–20.07) and comparatively short tail (c = 5.71–7.24: 4.74–5.04).

H. splendidus sp. n. differs from H. tarda by the extension of the cervical spines, which in the latter end at the middle of the basal bulb. In H. tarda the eggs are smooth and its measurements notably smaller (0.085×0.030 vs. 0.098 –0.108 × 0.043 –0.053).

Type host. Passalus interstitialis Escholtz, 1829 ( Coleoptera : Passalidae ).

Site. Gut caeca.

Type locality. Escaleras de Jaruco, Jaruco, La Habana Province, Cuba.

Etymology. Specific epithet is derived from the Latin splendidus , splendid, due to the beauty of the species.