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

Two new species of hystrignathids (Oxyurida: Hystrignathidae) are described as parasites of Passalus interstitialis Escholtz, 1829 from Cuba. Hystrignathus splendidus sp. n. diff ers from H. infl atus Travassos & Kloss, 1957 by having the eggs ridged, a stouter body and a shorter tail, and from H. tarda (Artigas, 1928) by its eggs being ridged and larger. Lepidonema magnum sp. n. can be diff erentiated from L. brasiliensis Travassos & Kloss, 1957 by the extension of the lateral alae, length of the fi rst cephalic annule and the stouter body. It diff ers from L. teresae Garcia, Ventosa & Morff e, 2009 by the esophagus and tail being comparatively shorter. L. bifurcata Cobb, 1898 diff ers from the new species by having the tail tip bifurcated. L. caracae Kloss, 1962 has more extended lateral alae and a shorter esophagus. Keys to the Cuban species of Hystrignathus and Lepidonema are given. Longior similis Morff e, Garcia & Ventosa, 2009 is recorded from El Pan de Matanzas, Matanzas Province, Cuba. ZooKeys 49: 1–11 (2010) doi: 10.3897/zookeys.49.402 www.pensoftonline.net/zookeys Copyright J. Morffe, N. Garcia. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. RESEARCH ARTICLE Launched to accelerate biodiversity research A peer-reviewed open-access journal


Introduction
Th e family Passalidae consists of a group of saproxylophagous and pan-tropical beetles with about 650 known species (Reyes-Castillo 2000). Due to their feeding habits passalids are frequently parasitized by monoxenous nematodes belonging to the family Hystrignathidae.
In this paper two new species of hystrignathid parasites of P. interstitialis are described and a new locality for Longior similis Morff e, García and Ventosa, 2009 is recorded from the same host.

Materials and methods
Nine specimens of Passalus interstitialis Escholtz, 1829 (eight from Escaleras de Jaruco, La Habana Province and one from El Pan de Matanzas, Matanzas Province) were collected by hand from rotting logs. Th e beetles were maintained alive in jars with moistened wood chips as food until dissection. Th ey were killed in a killing jar with ethyl ether or acetone and immediately dissected according to Morff e et al. (2009). Nematodes extracted from their guts were killed with hot water (60-70°C) and fi xed in 70% ethanol.
Specimens were clear-mounted in glycerine on glass slides and the edges of coverslips sealed with nail polish (Jex et al. 2004). Measurements were taken according to Travassos and Kloss (1958) and are given in millimeters. Variables are showed as range followed by median plus standard deviation in parentheses. De Man's ratios a, b, c and V% were calculated.
Parasites were photographed with an AxioCam digital camera attached to a Carl Zeiss compound microscope. Line drawings were made with CorelDRAW X3 and Adobe Photoshop CS2 using micrographs as templates. Scales of all plates are given in millimeters.
Th e type specimens are deposited in the Colección Helmintológica from the Colecciones Zoológicas del Instituto de Ecología y Sistemática, Havana, Cuba (CZACC).  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 fi rst 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 infl ated, about three head-lengths long and set-off from head by single groove. Stoma long, extending for about fi rst 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 infl ated. 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 refl exed at about half of body-width posterior to excretory pore, with distal fl exure about a body-width long. Posterior ovary shorter and not refl exed. Eggs ovoid with eight longitudinal but not very prominent ridges on shell. Tail conical, comparatively short, slightly subulate, ending in fi ne tip. Male unknown.
Diff erential diagnosis. H. splendidus sp. n. can be easily diff erentiated from most species of the genus by the long and infl ated fi rst cephalic annule. It shares this feature with H. tarda (Artigas, 1928)     Description. Female body large and robust. Cuticle markedly annulated in spiny region (annule about 0.008 mm width) and less in rest of body. Th ese annules almost disappear in last third of body. Cervical cuticle with opposite rows of spines from end of fi rst cephalic annule to midpoint of basal bulb or very short distance beyond its end, arranged initially in 16 rows of robust, scale-like spines increasing to about 20 rows of thinner spines where they end. Longitudinal sub-cuticular striae present. Lateral alae well developed, from short distance posterior to end of spines (about 0.2 body-widths) to level of vulva. Head short, bearing eight small papillae arranged in pairs. First ce-phalic annule long, with rounded margins and almost equivalent to head-width. Stoma stout, short, hardly extending posterior to fi rst cephalic annule. Esophagus with powerful, muscular and sub-cylindrical procorpus which has base set off from short isthmus. Basal bulb sub-spherical; valve plate well developed. Intestine simple, sub-rectilinear, with fore region strongly dilated. Rectum short; anus not prominent. Nerve ring surrounding procorpus at about half of its length. Excretory pore situated at little less than body width posterior to basal bulb. Vulva a median transverse slit near mid-body; lips not prominent. Vagina muscular, forwardly directed. Genital tract didelphic-amphidelphic. Ovaries similar in length and refl exed; distal fl exures of about 1.5 body-widths in length. Anterior ovary refl exed just posterior to excretory pore. Posterior ovary refl exed at about 2.6 body-widths anterior to anus. Eggs comparatively small, ovoid; shell smooth and thin. Tail short, conical, subulate, ending in fi ne tip. Male unknown.
Diff erential diagnosis. L. magnum sp. n. is similar to L. brasiliensis Travassos & Kloss, 1957 in body length (2.415-2.710 vs. 2.640-2.850), the comparative length of the esophagus (b = 4.60-4.96: 4.71-4.83), spines which cease a short distance pos-  terior to the bulb in one specimen (in the other specimens they end at the midpoint of the basal bulb) and the termination of the lateral alae at the level of the vulva. L. magnum sp. n. can be distinguished from L. brasiliensis by the lateral alae arising at about 0.2 body-widths posterior to the end of the spines but without actually reaching them. In L. brasiliensis the lateral alae commence at the end of the spines. Also, L. magnum sp. n. has a shorter fi rst cephalic annule (0.018 vs. 0.028-0.038), stouter body Th e specimens from El Pan de Matanzas exhibit a slightly shorter body and esophagus. Th e remaining measurements, including De Man's ratios, agree with the type population (Table 1).