Coynema poeyi (Coy, Garcia & Alvarez, 1993) Morffe & Garcia

Rodriguez, Jans Morffe & Rodriguez, Nayla Garcia, 2011, Coynema gen. n., a new genus of nematode (Thelastomatoidea, Hystrignathidae) parasites of Passalidae (Coleoptera) from Cuba, ZooKeys 75, pp. 9-19 : 11-14

Coynema poeyi (Coy, Garcia & Alvarez, 1993) Morffe & Garcia comb. n. Figure 1 A–HFigure 2 A–CFigure 3 A–H

Glaber poeyi Coy, García & Alvarez, 1993: 57-59, fig. 3 A–E

Type material.

♂ holotype of Glaber poeyi , Cuba, Pinar del Río Province, Sierra del Rosario, El Salón; in Passalus interstitialis ; IV.1990; A. Coy & N. García coll.; CZACC 11.4168. ♀ allotype of Glaber poeyi , same data as holotype, CZACC 11.4169.

Other material examined.

5 ♀♀, Cuba, Pinar del Río Province, Sierra del Rosario, El Mulo; in Passalus pertyi ; X.2007; R. Núñez & O. Madruga coll.; CZACC 11.4468-11.4472. 9 ♀♀, Cuba, La Habana Province, San José de las Lajas, La Jaula; in Passalus pertyi ; 15.III.2008; E. Fonseca, J. Morffe, G. León & F. Alvarez coll.; CZACC 11.4611-11.4619. 2 ♀♀, same data as anterior, deposited in the CHIOC. 6 ♀♀, Cuba, Holguín Province, Nipe-Sagua-Baracoa, La Melba; in Passalus pertyi ; V.2007; R. Barba & D. Ortiz coll.; CZACC 11.4460-11.4465. 4 ♂♂, same data as anterior; CZACC 11.4473-11.4476.

Type host.

Passalus interstitialis Escholtz, 1829 ( Coleoptera , Passalidae ).

Other host.

Passalus pertyi Kaup, 1869 ( Coleoptera , Passalidae ).

Site.

Gut caeca.

Type locality.

El Salón, Sierra del Rosario, Pinar del Río Province, Cuba.

Other records.

El Mulo, Sierra del Rosario, Pinar del Río Province, Cuba; La Jaula, San José de las Lajas, La Habana Province, Cuba; La Melba, Nipe-Sagua-Baracoa, Holguín Province, Cuba.

Measurements.

Holotype (male) a = 14.40, b = 5.74, c = 83.08, total length = 1.080, maximum body width = 0.075, stoma length = 0.018, procorpus length = 0.130, isthmus length = 0.023, diameter of basal bulb = 0.038, total length of esophagus = 0.188, nerve ring to anterior end = 0.098, excretory pore to anterior end = 0.260, cloaca to posterior end = 0.013.

Allotype (female) a = 16.69, b = 9.15, c = 4.41, V% = 52.63, total length = 2.470, maximum body width = 0.148, first cephalic annule ( length×width) = 0.013 × 0.035, stoma length = 0.025, procorpus length = 0.200, isthmus length = 0.025, diameter of basal bulb = 0.065, total length of esophagus = 0.270, nerve ring to anterior end = 0.130, excretory pore to anterior end = 0.370, vulva to posterior end = 1.170, anus to posterior end = 0.560, eggs = 0.113 –0.118×0.048– 0.050 (0.116 ± 0.004 × 0.049 ± 0.001 n = 2).

Population from El Mulo, Pinar del Río Province.

Females (n = 5) a = 17.00-19.72 (18.25 ± 1.32 n = 4), b = 7.73-8.65 (8.18 ± 0.38 n = 4), c = 3.65-3.99 (3.82 ± 0.17 n = 4), V% = 46.99-52.94 (49.50 ± 2.84 n = 4), total length = 1.700-2.075 (1.863 ± 0.164 n = 4), maximum body width = 0.090-0.120 (0.102 ± 0.011 n = 5), first cephalic annule ( length×width) = 0.008 –0.013×0.023– 0.030 (0.010 ± 0.002 × 0.026 ± 0.004), stoma length = 0.018-0.020 (0.019 ± 0.001 n = 5), procorpus length = 0.160-0.175 (0.166 ± 0.006 n = 5), isthmus length = 0.023-0.025 (0.023 ± 0.001 n = 5), diameter of basal bulb = 0.040-0.045 (0.043 ± 0.002 n = 5), total length of esophagus = 0.220-0.240 (0.226 ± 0.009 n = 5), nerve ring to anterior end = 0.108-0.128 (0.119 ± 0.009 n = 5), excretory pore to anterior end = 0.340 (0.340 n = 1), vulva to posterior end = 0.800-1.100 (0.944 ± 0.133 n = 4), anus to posterior end = 0.430-0.520 (0.484 ± 0.038 n = 5), eggs = 0.105 –0.113×0.035– 0.048 (0.110 ± 0.003 × 0.040 ± 0.003 n = 11).

Population from La Jaula, La Habana Province.

Females (n = 11) a = 13.13-20.00 (16.26 ± 1.95 n = 11), b = 7.65-9.33 (8.35 ± 0.53 n = 11), c = 3.93-4.49 (4.22 ± 0.19 n = 10), V% = 47.72-51.92 (50.44 ± 1.07 n = 11), total length = 1.740-2.425 (2.010 ± 0.211 n = 11), maximum body width = 0.108-0.150 (0.125 ± 0.014 n = 11), first cephalic annule ( length×width) = 0.005 –0.008×0.028– 0.033 (0.007 ± 0.001 × 0.029 ± 0.002 n = 7), stoma length = 0.020 (0.020 n = 11), procorpus length = 0.163-0.185 (0.174 ± 0.008 n = 11), isthmus length = 0.020-0.028 (0.023 ± 0.003 n = 11), diameter of basal bulb = 0.043-0.058 (0.049 ± 0.005 n = 11), total length of esophagus = 0.228-0.260 (0.240 ± 0.010 n = 11), nerve ring to anterior end = 0.120-0.140 (0.130 ± 0.006 n = 11), excretory pore to anterior end = 0.280-0.360 (0.320 ± 0.029 n = 11), vulva to posterior end = 0.860-1.200 (0.996 ± 0.107 n = 11), anus to posterior end = 0.400-0.560 (0.478 ± 0.061 n = 10), eggs = 0.108 –0.125×0.035– 0.048 (0.116 ± 0.004 × 0.042 ± 0.004 n = 20).

Population from La Melba, Holguín Province.

Females (n = 6) a = 13.27-16.00 (14.80 ± 0.95 n = 6), b = 6.77-8.38 (7.53 ± 0.57 n = 6), c = 3.35-3.84 (3.60 ± 0.20 n = 6), V% = 43.18-48.24 (44.92 ± 2.27 n = 4), total length = 1.460-1.800 (1.653 ± 0.126 n = 6), maximum body width = 0.110-0.120 (0.112 ± 0.004 n = 6), first cephalic annule ( length×width) = 0.010 ×0.025– 0.028 (0.010 × 0.027 ± 0.001 n = 5), stoma length = 0.018-0.020 (0.018 ± 0.001 n = 6), procorpus length = 0.153-0.173 (0.160 ± 0.008 n = 6), isthmus length = 0.018-0.200 (0.019 ± 0.001 n = 6), diameter of basal bulb = 0.043-0.065 (0.048 ± 0.009 n = 6), total length of esophagus = 0.200-0.240 (0.220 ± 0.014 n = 6), nerve ring to anterior end = 0.113-0.125 (0.119 ± 0.006 n = 6), excretory pore to anterior end = 0.270-0.360 (0.307 ± 0.047 n = 3), vulva to posterior end = 0.820-1.000 (0.894 ± 0.076 n = 4), anus to posterior end = 0.380-0.530 (0.462 ± 0.052 n = 6), eggs = 0.105 –0.125×0.035– 0.048 (0.113 ± 0.006 × 0.043 ± 0.004 n = 11).

Males (n = 4) a = 10.84-13.18 (11.87 ± 1.05 n = 4), b = 5.62-6.03 (5.88 ± 0.18 n = 4), c = 55.00-74.67 (66.92 ± 8.39 n = 4), total length = 1.030-1.120 (1.073 ± 0.044 n = 4), maximum body width = 0.085-0.095 (0.091 ± 0.004 n = 4), stoma length = 0.015-0.020 (0.017 ± 0.002 n = 4), procorpus length = 0.125-0.300 (0.128 ± 0.002 n = 4), isthmus length = 0.015-0.023 (0.018 ± 0.004 n = 4), diameter of basal bulb = 0.040-0.048 (0.044 ± 0.003 n = 4), total length of esophagus = 0.175-0.188 (0.183 ± 0.005 n = 4), nerve ring to anterior end = 0.093-0.100 (0.096 ± 0.003 n = 4), excretory pore to anterior end = 0.240-0.250 (0.248 ± 0.005 n = 4), cloaca to posterior end = 0.015-0.020 (0.016 ± 0.003 n = 4).

Description.

Female. Body comparatively robust, markedly fusiform, maximum width at level of the anterior part of intestine. Cervical cuticle unarmed, finely annulated (annule more conspicuous toward post-esophageal region). Sub-cuticular longitudinal striae present. Lateral alae from the end of procorpus or the beginning of its basal dilation to about half of a body width before the level of vulva. Head well developed, set-off from body by a single, deep groove and bearing eight small paired papillae. First cephalic annule slightly expanded, when totally stretched (in dead nematodes inside the hosts) consisting of an anterior half with concave margins (its diameter initially inferior to that of head and increasing gradually in the posterior direction) and a posterior half wider and with convex margins. In heat-relaxed specimens the cephalic annule appears to be less stretched and only the posterior part is visible. Stoma short, about two first cephalic annule lengths long, surrounded by an esophageal collar. Esophagus consists of a muscular, sub-cylindrical procorpus, base abruptly dilated in its joint with the short isthmus. Basal bulb pyriform, valve plate well developed. Intestine simple, sub-rectilinear, anterior portion notably dilated, forming a sac-like structure slightly longer than esophagus. In this part the external surface of intestine almost touching the body wall. The continuation of intestine is about one third of the diameter of the sac-like structure. Rectum short, anus not prominent. Nerve ring encircling procorpus at about 60% of its length. Excretory pore situated at about half of a body width posterior to basal bulb. Genital tract didelphic-amphidelphic, both ovaries thin, reflexed. Anterior ovary commencing just behind the saccular structure and posterior ovary arising slightly more than a body width anterior to the level of anus. Vulva a median transverse slit near midbody or slightly displaced forward, lips more or less prominent. Vagina muscular, thin-walled, forwardly directed. Conduct next to the vagina forming a loop. Eggs comparatively large, markedly ovoid in shape, smooth-shelled. Tail comparatively long, filiform and subulate.

Male. Body shorter and slender than female. Cervical cuticle unarmed. Sub-cuticular longitudinal striae present. Cephalic end similar to female, except by the cephalic annule inconspicuous. Digestive system similar to female. Sac-like region of the intestine slightly larger than the esophagus. Rectum short and cloaca inconspicuous, not prominent. Nerve ring encircling procorpus in posterior half, at about 60% of its length. Excretory pore situated at about less than a body-width posterior to the basal bulb. Testis single, commencing just posterior to the sac-like structure of intestine. Tail conical, sharply pointed, very short and ventrally curved. Dorsal cuticle near the tail tip bearing a Y-like thickening, its inferior part posteriorly directed. A single, median, large, mammiform pre-cloacal papilla present. A pair of small, sub-dorsal, pre-cloacal papillae situated before the dorsal cuticular thickening. Spicules absent.

Discussion.

Coynema gen. n. can be placed in Hystrignathidae by having males with the single median pre-cloacal papilla characteristic of the family, oesophagus with its anterior portion supported by cuticularized rods and elongated eggs ( Adamson and Van Waerebeke 1992). The new genus has affinities with the Brazilian genus Glaber by having a similar arrangement and form of the first cephalic annule and the characteristic basal dilation of the procorpus. A similar procorpus is present in Vulcanonema Travassos & Kloss, 1958, that however differs in its first cephalic annule separated from head by a conical region. These last two genera can be differentiated from Coynema gen. n. in having a monodelphic-prodelphic reproductive system. The marked fusiform shape of Coynema gen. n. only appears in the monotypic Malagasian genus Passalidophila Van Waerebeke, 1973, which is also monodelphic.

There are eight hystrignathid genera that are digonant and lack spines in the cervical cuticle: Anomalostoma Cordeira, 1981; Anuronema , Klossnema Cordeira & Artigas, 1983; Papillabrum Cordeira, 1981; Phalacronema , Sprentia , Triumphalisnema Kloss, 1962 and Ventelia Kloss, 1962. Coynema gen. n. differs from all of them in the form of cephalic end, the esophagus and the sac-like structure of the intestine. At present, the latter feature appears to be unique in the family.

The male of Coynema gen. n. presents the head and digestive system very similar to female. This is unusual in the few genera of Hystrignathidae having males described, which have a cylindrical procorpus. Due to this, the shape of the digestive system differentiates the males of Coynema gen. n. from the other males of Hystrignathidae .

Comments.

There are small metric differences in the average values among females from some of the populations studied. In spite of this measurements tend to overlap, and there were no evident morphological differences observed. Males from El Salón and La Melba did not show marked morphometric variation. In addition, no male specimens were found in the populations from El Mulo and La Jaula, when looking for more features that would support the existence of other species of Coynema gen. n. These are the reasons why all populations are considered conspecific until larger series of specimens are at hand for further study.