Buzionema lutgardae, Morffe & García & Hasegawa & Carreno, 2021

Morffe, Jans, García, Nayla, Hasegawa, Koichi & Carreno, Ramon A., 2021, Morphological and molecular characterization of Buzionema lutgardae n. sp (Nematoda: Oxyuridomorpha: Thelastomatidae) from the cockroach Byrsotria sp. (Blattaria: Blaberidae) in Cuba, Zootaxa 4965 (2), pp. 385-395 : 387-393

Buzionema lutgardae n. sp.

Fig. 1 A–E , Fig. 2 A–F , Fig. 3 A–H

Type material. Holotype: ♀, Cuba, Camagüey province, Sierra de Cubitas, Reserva Ecológica “Limones-Tuabaqu- ey”; in Byrsotria sp. ; XII/2015; J. Morffe, N. García coll.; CZACC 11.7339 . Paratypes: 11♀♀, same data as the holotype; CZACC 11.7340 –11.7350 . 11♂♂, same data as the holotype; CZACC 11.7351 –11.7361 .

Description. Female. Body robust, markedly spindle-shaped, with the maximum body-width at level of the midpoint of the oesophagus. Cervical cuticle unarmed. Cuticle with annuli from the base of the lips to ca. level of anus. Annuli visible from base of lips to level of vulva (ca. 12 µm); annuli posterior to vulva less marked and slightly wider (ca. 15 µm). Lateral alae well-developed from ca. the midpoint of cylindrical part of procorpus to level of anus. Oral aperture triangular, with isometric sides, one dorsal and two sub-ventral, lined by a cuticular band. Cuticle at midpoint of band extending and forming a triangular flap. Three large, isomorphic and isometric lips surrounding mouth, arranged as one dorsal and two sub-ventral lips, coinciding with sides of oral opening. Lips sub-triangular, with vertices rounded and edges convex. Amphids lateral in position, pore-like, located in cuticular prominences at distal vertex of each sub-ventral lip. Buccal capsule short, wide, notably cuticularized, its lumen triradiate. Several drop-like, dark cells surrounding buccal capsule. Oesophagus consisting of a corpus with swollen, fusiform anterior muscular part, and slender cylindrical posterior part, its diameter similar to that of isthmus. Junction of cylindrical part of corpus with isthmus barely evident. Length of anterior part of corpus ca. 1.5 posterior parts-length. Basal bulb rounded, valve-plate well developed. Intestine simple, sub-rectilinear, its anterior region dilated. Rectum short. Anus a crescent-like slit, its convex side anteriorly directed. Nerve ring encircling procorpus at level of its anterior part, a short distance behind its junction with buccal capsule. Excretory pore ventral, located at ca. last third of cylindrical part of corpus. Vulva a ventro-median transverse slit, displaced to posterior half of body. Vagina vera muscular, anteriorly directed. Genital tract didelphic-amphidelphic. Both ovaries reflexed. Oocytes in single rows. Eggs broadly oval, with thin and smooth shell. Tail comparatively long ca. one third of the body length, filiform, subulate, ending in fine tip.

Male. Body smaller and less robust than that of females; posterior end ventrally curved. Anterior end bluntly rounded. Lateral alae well-developed from ca. base of basal bulb to a distance (ca. 150 µm) before posterior end. Cephalic cap ca. 35 µm, conical, truncate, with smooth cuticle, without distinctive papillar structures. Cuticle unarmed, with conspicuous, wide annuli from base of cephalic cap to level of first pair of pre-cloacal papillae. Annuli of ca. 8 µm at level of first portion of corpus and ca. 5 µm at level of first pre-cloacal pair of papillae. Mouth dorso-ventrally orientated, sub-rectangular in shape, with the shorter sides dorsal and ventral and the longer lateral. Each lateral side of mouth presenting a sub-triangular projection, creating a bilobed appearance. Amphids porelike, located in each lateral projection of mouth. Buccal capsule short. Several drop-like, long dark cells originating near level of buccal capsule and extending to about half of distance between base of buccal capsule and nerve ring. Oesophagus consisting of muscular, sub-cylindrical corpus, slightly diminishing its diameter toward the cylindrical isthmus, its anterior end slightly expanded. Basal bulb rounded, valve-plate well developed. Intestine simple, subrectilinear, its anterior region dilated. Nerve ring encircling corpus at ca. 60% of its length. Excretory pore ventral, located at level of isthmus. Monorchic. Testis ventral, reflexed at ca. 50 µm posterior to basal bulb, distal flexure ca. a body-width length. Vas deferens divided into three regions: an anterior region filled with rod-like spermatids, a median region with rounded cells and a posterior region with longer polygonal cells, increasing slightly in diameter and then gradually tapering towards its junction with cloaca. Regions immediately anterior and posterior to cloaca with wrinkled cuticle, conferring a rough appearance. Short, posteriorly directed cuticular flap present at anterior lip of cloaca. Two digitiform cuticular projections present just posterior to cloaca, one on each side of cloaca. Spicule absent. Six copulatory papillae present, four pre-cloacal and two post-cloacal. First pre-cloacal pair ventromedian, papillae close to each other located at ca. 13 µm from cloaca. Second pair of pre-cloacal papillae formed by larger, rounded and prominent papillae, sub-lateral in position, located at short distance (ca. 5 µm) posterior to first precloacal pair. Sensilla of each papilla of second pre-cloacal pair surrounded by eight small protuberances. One pair of post-cloacal papillae present: a ventral pair of minute papillae near tail tip (ca. 7 µm). Tail short, conical, ending in sharp tip.

Differential diagnosis. The females of B. lutgardae n. sp. present the body notably shorter than that of B. validum (1600–2150 µm vs. 3131–3378 µm), but the oesophagus is comparatively longer (b = 2.96–3.77 vs. 4.65–4.87). The lateral alae of B. validum extend from the base of the basal bulb to the level of the anus, in contrast to B. lutgardae n. sp., with lateral alae from ca. the midpoint of the cylindrical part of the procorpus to the level of the anus. The larger diameter of the eggs is bigger in B. validum (81–88 µm vs. 63–75 µm).

The males of B. lutgardae n. sp. are shorter than those of B. validum (780–940 µm vs. 1177–1423 µm). In the new species the origin of the lateral alae near the level of the basal bulb is similar to B. validum , but in the case of the latter species they end at the level of the cloaca ( Kloss 1966), rather than some distance (ca. 150 μm) before the cloaca.

Type locality. Reserva Ecológica “Limones-Tuabaquey”, Sierra de Cubitas , Camagüey province, Cuba .

Other localities. Los Pinos beach, Key Paredón Grande, Sabana-Camagüey archipelago, Camagüey province, Cuba. Las Coloradas beach, Key Coco, Sabana-Camagüey archipelago, Ciego de Ávila province, Cuba ( García & Coy 1998).

Type host. Byrsotria sp. ( Insecta: Blattaria: Blaberidae ).

Site. Hind gut.

Etymology. Specific epithet dedicated to Dr. Lutgarda González Géigel (1948–2006) eminent Cuban botanist. This is a homage to an excellent human being and professor of the senior and second authors as well as several generations of Cuban biologists.

DNA studies. Two partial sequences of the D2-D3 region of the 28S rDNA were obtained from females of B. lutgardae n. sp. and B. validum (721 bp and 1029 bp, respectively). Both sequences differ in 79 homologous positions in an alignment of 733 bp. In addition, two partial sequences of the 18S rDNA were obtained from females of B. lutgardae n. sp. and B. validum (815 bp and 1652 bp, respectively). The differences between both sequences are two homologous positions (in an alignment of 809 bp).

In both ML and BI phylograms both species of Buzionema form a monophyletic clade with strong nodal support, as sister-group of Leidynema Schwenck in Travassos, 1929. The clade of Buzionema + Leidynema is also well-supported.

Figures

FIGURE 1. Buzionema lutgardae n. sp. Female. A. Oesophageal region, vental view. B. Tail, ventral view. C. Cephalic end, optical section. D. Cephalic end (reconstructed from SEM images). E. Genital tract, ventral view. F. Habitus, ventral view.

FIGURE 2. Buzionema lutgardae n. sp. Male. A. Oesophageal region, ventral view. B. Cephalic end, optical section. C. Cephalic end, en face view (reconstructed from SEM images). D. Tail, ventro-lateral view. E. Tail end, ventral view (reconstructed from SEM images). F. Habitus, ventral view.

FIGURE 3. Buzionema lutgardae n. sp., SEM images. Female.A. Cephalic end, en face view. B. Cephalic end, lateral view. C. Cephalic end, ventral view. D. Detail of the cephalic end. Male. E. Cephalic end, en face view. F. Tail end, ventral view. G, H. Tail end, ventral view. Scale bars: A, B, C, D, F, G, H. 10 µm. E. 5 µm.