Oswaldofilaria kanbaya n. sp., a new filarioid worm (Nematoda ; Filarioidea) from the saltwater crocodile Crocodilus porosus from Australia

© Masson, Paris, 1985. Ann. Parasitol. Hum. Comp., 1986, 61, n° 2, pp. 245-254. OSWALDOFILARIA KANBAYA n. sp., A NEW FILARIOID WORM (NEMATODA; FILARIOIDEA) from the saltwater crocodile Crocodilus porosus from Australia R. MANZANELL SUMMARY. A new species of filarial worm, Oswaldo filaria kanbaya is described from Crocodilus porosus from Australia. This is the fourth species of the genus inhabiting a crocodilian host. Morphologically these four species are found to be very similar in some primitive features, although they are dispersed over the three southern continents. Oswaldofilaria kanbaya n. sp., filaire nouvelle (Nematoda ; Filarioidea) de Crocodilus porosus en Australie. RÉSUMÉ. Description d’une nouvelle Filaire, Oswaldofilaria kanbaya n. sp., chez Crocodilus porosus en Australie. Quatre espèces du genre sont maintenant connues chez les Crocodiles. Bien qu’elles soient réparties dans les 3 continents austraux, elles sont morphologiquement proches par un ensemble de caractères primitifs. Introduction The three filarial parasites of crocodilians so far known all belong to the genus Oswaldofilaria Travassos 1933, sensu Bain (1974). Two of them were found in the Neotropical Region (Brazil), i.e. O. bacillaris (Molin, 1858) in Caiman crocodilus and in Melanosuchus niger (= Caiman sclerops and Champsa nigra respectively as referred to by Travassos, 1933) and O. medemi Marinkelle 1981 in Paleosuchus trigonatus from Colombia. The third species, O. versterae Bain, Kouyate and Baker, 1982, occurs in Crocodilus niloticus from the Ethiopian Region (« South Rhodesia »). A new Oswaldofilaria species is described below ; it is of particular interest as it also occurs in a crocidilian host, but was collected from the Australian Region. Department of Parasitology, University of Queensland, St. Lucia 4067, Australia. Present adress : Kantonsschule Rychenberg, Biologische Abteilung, Rychenbergstrasse 110, 8400 Win terthur, Switzerland. Accepte le 22 avril 1985. Article available at http://www.parasite-journal.org or http://dx.doi.org/10.1051/parasite/1986612245 R. MANZANELL 246 Material examined All specimens and bloodsamples were collected by Elisabeth Hagon, University of Sydney, Australia, and kindly submitted to the author. 5 male and 10 female worm specimens were removed from the connective tissues and serous membranes of the body cavity of one individual Crocodilus porosus, found infected near Maningrida, Northern Territories ; Australia. The worms were killed in 4 % hot formalin solution. Microfilariae were observed in dry and stained bloodfilms and in fresh bloodsmears prepared with vital stains (New Blue R). Description Oswaldofilaria kanbaya Measurements in table I. Cuticle with clearly evident transverse striation over whole length of body except at the anterior and posterior ends. Body cylindrical in anterior part, tapering in posterior fifth of length to fine rounded tip of tail. Head end inflated with cuticle surrounding mouth protruding from inflated part, with evenly rounded apex (fig. 1A ; 2 A). Four externolateral labial papillae distributed in rectangle (fig. 2 D ; 3), other papillae inconspicuous, amphid in groove (fig. 4), circular mouth with opening of 8 μm in diameter in center of head end (fig. 5). Buccal capsule narrow at entrance, widening towards base to maximal diameter of 20 μm. Walls of buccal capsule sepa rable into three parts, comprising a) flat cuticularised ring around mouth opening with tapering outer margines curved posteriad ; b) walls of buccal capsule funnelshaped with wider diameter posteriad ; c) flat cuticularised ring covering anterior tip of cesophagus. Oesophagus measuring three millimeters or more in both sexes, with short anterior muscular part (about 15 % of whole œsophagus) and posterior glan dular part. Nerve ring loosely structured around posterior part of muscular œsophagus (fig. 1 A ; 2B). No deirids seen. Oesophageal lumen enlarged at oesophagointestinal junction, bordered by folded cuticular lining of oesophageal valve (fig. 1B ; 2 C). Diameter of intestine at junction much smaller than diameter of glandular œsophagus. Intestine containing clearly distinguishable, partially or undigested red and white blood cells and few microfilariae as solid particles in specimens of both sexes (fig. 2 E). Phasmids forming prominent cone in subterminal lateral position of tail in males and females (fig. 8 ; 9). Male : Posterior end coiled ventrally (fig. 1C). Spicules unequal and dissimilar, left spicule being almost five times longer than right spicule. Both spicules posi tioned along midline of body, right spicule appearing at cloaca posterior to left spicule. Left spicule curved ventrally in longitudinal axis, slender, with head poorly developed, anterior shaft cylindrical and as long as posterior blade. Blade with core F ig . 1. — Oswaldofilaria kanbaya, male. A : Anterior end with muscular œsophagus. Note articulated buccal capsule and swelling of subapical part of body of worm. B : Oesophago-intestinal junction. C : Tail, with spicules in situ. D : Tail, latero-ventral view. E : Tail, ventral view. F : Right spicule, drawing with transmitted light from right side. G : Right spicule, aberrant form found in one specimen. H : Posterior part of ejaculatory duct, 6.3 mm distant from tip of tail, showing isthmus and anterior end of muscular layer with parallel striation. R. MANZANELL 248 T ab le I. — Measurements of Oswaldofilaria kanbaya. MA L E S P E C I M E N S Holo 5 specimens, Average type range Body length 18 Oesophagus length 3.20 Oesophagus length as % of body length18 % length of glandular 2.8 oesophagus 0.015 Depth of buccal capsule 0.18 Tail length — Vulva, from ant. end Vulva, as % of body — length 0.55 Left spicule Right spicule 0.11 Length of right spicule as % of left spicule 20% Body width : 0.16 at post, end of oes. at midbody/vulva 0.15 0.09 at cloaca F E M A L E S P E C I ME NS Allo type 10 speci Average mens, range 16-18 3.0-3.5 17 3.2 31 3.5 26-36 3.5-4.5 32 4.2 18-22 19 % 11 % 11-15 % 13 % 2.4-3.0 0.015 0. 17-0.18 2.76 0.015 3.0-4.0 0.02 0.28-0.32 8.2-9.9 3.6 0.02 — 3 0.02 0.32 9.2 — — 0.48-0.55 0.51 30 % 25-35 % 29% — — — — 0.17 0.31 9.2 0 . 11-0.12 0.11 — — — 20-25 % 22 % — — — 0. 15-0.16 0.15 0.15 0.09 0.25 0.25 0.08 0.15-0.16 0.08-0.09 0.22-0.28 0.23-0.26 0.07-0.09 0.25 0.25 0.08 flattened and margins laterally expanded and bent over ventral side to form tube leaving anterior opening at junction with shaft and posterior opening near tip were margins decrease in size. Tip of left spicule solid, pointed, formed by tapering core. Right spicule straight with head conspicuous with antero-ventral margin elongated and directed towards anterior of body of worm (fig. 1 F ) ; adjacent shaft cylindrical, flattening posteriorly to form channel with convex side facing towards left spicule. Tip formed by rounded, but sharp-edged, flattened margin. Right spicu (...truncated)