Slender Spicules Research Articles

Zeatylenchus pittosporum gen. n., sp. n. (Tylenchida: Anguinata), from leaves of Pittosporum tenuifolium (Pittosporaceae) in New Zealand

A new genus and species of anguinid nematode, Zeatylenchus pittosporum gen. n., sp. n., was recovered from leaves of Pittosporum tenuifolium from Hahei, Coromandel Region, North Island, New Zealand. The genus is characterised by having slender males and females, excretory pore opening near the lips and level with the knobs of the retracted stylet, pharynx with a weak non-muscular median bulb, pharyngeal glands overlapping the intestine, females with a single gonad with a quadricolumella and post-uterine sac; and males with slender arcuate spicules and the bursa arising <1 anal body diam. anterior to the cloacal aperture and extending ca 30% of distance to the tail tip. Its feeding does not induce galls, only foliar chlorosis. The species has particular characters, including a short, robust stylet with conus forming ca 40% of stylet length and small rounded compact knobs, and tail offset dorsally with a pointed tip. Molecular phylogeny of near full length small subunit, D2/D3 expansion segments of the large subunit and internal transcribed spacer rRNA genes support the description of Zeatylenchus pittosporum gen. n., sp. n. as a new genus and species.

Chromaspirina guanabarensis sp. n. (Nematoda: Desmodoridae) and a new illustrated dichotomous key to Chromaspirina species

A new species of Chromaspirina is described from Bica Beach, a polluted beach situated at Ilha do Governador, Guanabara Bay on the coast of Rio de Janeiro (Brazil). The new species belongs to the group of species within the genus which bears a poorly developed dorsal tooth. The new species is characterized by large body size, conoid tail shape, small acute dorsal tooth, long slender spicules with sclerotised hooked capitulum, and sexual dimorphism of the nonstriated part of the tail. A new illustrated dichotomous key to males of species of Chromaspirina is proposed.

Two new species of Comesomatidae Filipjev, 1922 (Nematoda: Chromadorida) from sandy bottoms of Tenerife, Canary Islands

Two new species of Comesomatidae Filipjev, 1922 are described from sandy bottoms of Tenerife, Canary Islands. Paracomesoma sigmoidalis new species is characterized by having 35 precloacal supplements, S-shaped and slender spicules, and an elliptical plaque at the distal end of the gubernaculum. Setosabatieria triangularis new species is characterized by the number of turns (2.5) and development of the amphid (68% cbd), and a triangular gubernaculum.

Studies on nematodes of the family Aulolaimoididae (Nematoda: Dorylaimida) with descriptions of five new species

Abstract Five new and two known species belonging to the family Aulolaimoididae are described and illustrated from India and Costa Rica. Adenolaimus minor sp. n. is characterised by the short body (L = 0.38-0.46 mm), stoma supported by minute ribs, monoopisthodelphic female genital system with a small pre-uterine sac, obtusely rounded tail and male with slender spicules. Adenolaimus loofi sp. n. is characterised by the 0.66-0.72 mm long body; stoma and pharyngeal walls supported by minute rib-like structures; truncate lip region; 4.0 μ m long odontostyle; odontophore with basal flanges; mono-opisthodelphic female genital system with anterior uterine sac 0.7-1.0 times corresponding body diam. long; short hemispheroid tail and males with two, spaced, ventromedian supplements. Adenolaimus clavatus sp. n. is characterised by the 0.90-1.01 mm long body; stoma and pharyngeal walls supported by minute rib-like structures; continuous, rounded, lip region; 5.5-6.0 μm long odontostyle; odontophore with basal flanges; mono-opisthodelphic female genital system with a small anterior uterine sac and short clavate tail. Adenolaimus tropicus sp. n. is characterised by the 0.75-0.80 mm long body; lip region rounded and offset by depression; 5 μm long odontostyle; pharyngeal bulb not constricted; anterior genital branch reduced to an uterine sac and short hemispherical tail. Oostenbrinkia parva sp. n. is characterised by the small body (L = 0.440.49 mm); 4.0 μm long odontostyle with forked base, flanged odontophore; post-median vulva; vagina with two slender sclerotised pieces; amphidelphic genital system and short, hemispheroid, tail. Two known species, Aulolaimoides elegans and Adenolaimus orthus are redescribed and the generic diagnosis of Oostenbrinkia is emended. A species compendium and key to the genera and species of Aulolaimoididae are provided.

The African Rhigonematoidea (Nematoda: Rhigonematida). 1. Trachyglossus quintus gen. n., sp. n. (Xustrostomatidae fam. n.) with redescription of Rhigonema multipapillatum (Skrjabin, 1916) and designation of a neotype

AbstractTrachyglossus quintus gen. n., sp. n. is described from Charactopygus frequens from Zaire. The new genus is characterised by having a dorsoventrally elongate oral aperture with the dorsal jawplate developed into a tongue-like rasp extending over halfway down the corpus lumen; a hypertrophied corpus and isthmus; well developed, lobate caudal alae in the male; hypertrophied, lobiform, vulval flap and by the form of the spicules and disposition of the copulatory papillae. It is closest to Xustrostoma, a genus with which it shares the development of a tongue-like rasp, but differs principally in the hypertrophy of the pharyngeal components: in Trachyglossus gen. n. it is the corpus and isthmus which are enlarged whereas in Xustrostoma it is the basal bulb. Trachyglossus gen. n. also differs in having strongly developed, lobate, caudal alae in the male (vs absent) and in possessing a lobiform anterior vulval lip. It differs from Obainia in having the dorsal jaw plate modified to form a tongue-like rasp, corpus and isthmus region of pharynx hypertrophied (vs basal bulb in African species of Obainia), hypertrophied vulval flap, form of spicules, distribution of copulatory papillae and presence of caudal alae in the male. From Zalophora it differs in the form of the pharynx, development of a tongue-like dorsal rasp instead of numerous teeth on the dorsal jawplate, presence of a hypertrophied vulval lobe and in being amphimictic instead of parthenogenetic. Xustrostomatidae fam. n. is proposed for all those genera (formerly included in the Rhigonematidae) with the cephalic capsule laterally compressed to form a dorsoventrally orientated oral aperture. Rhigonema multipapillatum (Skrjabin, 1916), previously known only from the original description, is redescribed and established as a valid species on the basis of material from Uganda. A neotype is proposed. The species is characterised by medium body size; posterior margin of cephalic collar fused to body; presence of fine microtrichs in the cervical region; cuticularised mouth plates clothed in minute spine-like structures; Type 1 female genital tract; conoid spicate tail shape in both sexes; form of the long, slender spicules and disposition of the 31 copulatory papillae, three postcloacal pairs of which being subdorsal or sublateral in position.

Thalassomonhystera traesti n.sp., Eumonhystera andrassyi and three Monhystrella species (Monhysteridae: Nematoda) from Li River, China

A new Thalassomonhystera species, i.e. T. traesti n.sp., and a new subspecies, Monhystrella lepidura chinensis n. subsp., together with Eumonhystera andrassyi (Biro, 1969) Andrassy, 1981, Monhystrella macrura (de Man, 1880) Andrassy, 1981 and Monhystrella iranica Schiemer, 1965 are described from Li River at Guiling, China. Thalassomonhystera traesti n.sp. is characterised by a combination of the following characters: expanded lip region, large and anteriorly situated amphids, prominent inner labial sensilla, and slender spicules and tube-like gubernaculum in males. Monhystrella lepidura chinensis n. subsp. belongs to Monhystrella lepidura (Andrassy, 1963) Andrassy, 1968 but differs from the three hitherto described subspecies in its possession of a pharynx that posteriorly expands into a double bulb. Monhystrella macrura, M. iranica and Eumonhystera andrassyiare reported here for the first time from China.

Philometra margolisi n.sp. (Nematoda: Philometridae) from the gonads of the red grouper, Epinephelus morio (Pisces: Serranidae), in Mexico

A new nematode species, Philometra margolisi n.sp., is described from the gonads of the serranid fish Epinephelus morio from Mexico (localities Telchac, Chuburna, Progreso, and Rio Lagartos, Yucatan). It is characterized mainly by long (0.432–0.468 mm) and slender spicules and a simple gubernaculum (length 0.084–0.093 mm) in the male and by body shape and size (length 65–85 mm), arrangement and number of small cephalic papillae (eight papillae in an outer circle and four in an inner one), structure and length (1.07–1.18 mm) of the esophagus, long ovaries, and the presence of a pair of small lateral papilla-like projections on the elongate caudal end in gravid females.

Epsilonematidae (Nematoda: Desmodoroidea) From the East African Coast, With a Discussion On the External Morphology of Cuticular Appendages

Morphological features of the cuticular appendages, such as spines, thorns, setae and flaps are described on the basis of SEM pictures of three new and three known species of the Epsilonematidae from East African coasts. Epsilonema espeeli sp.n. is characterized by the presence of six subcephalic setae and a large number of hair-like spines on the dorsal body side; males are characterized by three pairs of copulatory thorns, three precloacal thorns and an anal tube; females have a large citucular flap covering the vulva. Metepsilonema iuvenisspinosum sp.n. is characterized by its small size, ornamentation and shape of the body annules, conspicuous inversions in direction of the body annules (3 dorsal inversions and 1 ventral inversion), oval amphid, 4 pairs of supporting setae of which the third pair is the longest one in the males and the last pair the longest one in the female, length of the spicules and the subdorsal spines on the female (and juveniles) tail. Perepsilonema ritae sp.n. is characterised by sexual dimorphism in: amphidial shape (slit-like in the males, spiral in the females), number of subcephalic setae (8 in the males, 6 in the females), ornamentation of the body annules, sudden broadening of the body just behind the ventral body curvature and a slender annule posterior to the ventral body curvature. Males have large copulatory thorns and slender spicules. Additional morphological information on Epsilonema parvospina Decraemer, 1982, Metepsilonema bermudae Lorenzen, 1973 and Perepsilonema kellyae Gourbault & Decraemer, 1988 is presented and important external characteristics are illustrated with SEM pictures. The external morphology of the ambulatory setae is compared between specimens of the Epsilonematidae and one species of Draconematidae (Dracograllus eira (Inglis, 1968)).

Taxonomy of Some New and Known Species of the Genus Tylencholaimellus With a Proposal for Margollus Gen. N. (Nematoda: Dorylaimida)

In this paper two new species of the genus Tylencholaimellus (T. loofi and T. cylindricus) are described and new information is provided on T. projectus Siddiqi, 1964 from Malawi and T. hispanicus Pena Santiago & Coomans, 1990 which is transferred to a new genus, Margollus, with M. bellus as type species. Tylencholaimellus loofi sp. n. is characterized by body length 0.6-0.9 mm, lip region offset by a less marked constriction, stylet 19-20.5 μm, pharyngeal bulb 22-30 μm, V = 26.6-33.5, prevulval sac 14-30 μm (0.5-1.0 times the corresponding body width), tail convex conoid to hemispherical (14-30 μm long, c = 37-55 and c' = 0.65-1.1), and males absent. T. cylindricus sp. n. can be distinguished by body 0.7-1.0 mm long, lip region continuous, stylet 25-28 μm, pharyngeal bulb 26-36 μm long, V = 28.7-36, anterior uterine sac 40-90 μm long (0.7-2.2 times body diameter), female tail hemispherical (16-20 μm long, c = 41.8-68.7, c' = 0.5-0.6) and characteristically slender spicules 44-50 μm long. Margollus gen. n. is very close to Tylencholaimellus but differs from it in having a very well developed cephalic framework with labial and postlabial sclerotization. M. bellus sp. n. is recognized by the medium sized body (0.84-0.96 mm long), lip region attenuated with its most anterior part set off by a constriction and the posterior part continuous with the body, labial sclerotization with a hook-like anterior part, stylet 30-22 μm long, pharyngeal bulb length 27-31 μm, female tail convex conoid (its length 21 μm, c = 41.3, c' =1.0), spicules 33-36 μm long and only one ventromedian supplement present.

Monhysteridae From Western Sudan With Descriptions of Two New Species (Nematoda: Monhysterida)

This study deals with five species (two of them new) of the family Monhysteridae belonging to three genera and identified as: Monhystera uncigubernaculum sp. n., M. magnacephala, Eumonhystera sudanensis sp. n., Monhystrella paramacrura and M. hastata. Females of M. uncigubernaculum sp. n. are characterized by the presence of large coelomocytes in the region of the uterus; two to the right side of its posterior part and several on the left side of its anterior part, the presence of two large postvulval gland cells, large uterus and long anteriorly bent vagina. Males are characterized by the presence of large amphidial apertures, long slender spicules and the presence of a unique, long, hook-like, posteriorly directed gubernaculum. E. sudanensis sp. n. is characterized by the presence of perioral platelets, the more posterior position of amphidial apertures with clear amphidial canals and pouches, the presence of refractive ocellus-like bodies, clear outlets of pharyngeal glands and excretory pore and with shorter tail length compared to vulva-anus distance. The genus Monhystera is discussed. Eumonhystera crassa is differentiated from E. dispar. S.E.M. photo's are given for three species.

The Genus Axonchium (Nematoda: Belondiridae) Iii. Species With Vaginal Sclerotization (Part 1)

The species of Axonchium with vaginal sclerotization, but without disc-like structure between vulva and vagina are redescribed. This group is less uniform than that treated in the previous paper, it comprises the following species : A. coronatum (de Man, 1906), A. leptocephaluin Altherr, 1953, A. vaginatum Jairajpuri, 1965, A. valvulatum n.sp. and possibly A. macrophallum Thorne, 1939. Males, when present, have long and comparatively slender spicules.

A note on the specific identity of Trichostrongylus longispicularis Gordon, 1933.

The nematode Trichostrongylus longispicularis was described by Gordon (1933) from a single male recovered from a sheep in New South Wales. Gordon considered that the male of this species could be readily distinguished from the males of other species of the genus recorded from ruminants by an asymmetrical dorsal ray of the bursa and by the length and form of the spicules. The dorsal ray is described as being bifid, one bifurcation being simple and the other possessing secondary branches, one situated internally and the other externally. The slender spicules were 184·6 microns long, and terminated in fine sickle-shaped structures.Andrews (1934 and 1935) recorded the species from cattle in the United States. In his first description (Andrews, 1934) he noted that his specimens agreed very closely with the description published by Gordon (1933), but he referred to hook-like projections on the spicules. However, he failed to find these projections in the specimen discussed in his record of 1935. As he made no reference to the dorsal ray of the bursa, it is presumed that this agreed with the description and figure published by Gordon (1933). T. longispicularis was subsequently reported by Roberts (1938 and 1939) from cattle in Queensland, but no comments were made on its morphology.