Trois espèces d’Oxyures parasites de Poissons en Afrique

2015

Folia Parasitologica

Based on light and scanning electron microscopical studies, eight species (five adult and three larval) of nematodes belonging to the Ascaridida, Oxyurida and Enoplida were collected from fishes of the Okavango River, Botswana, namely Falcaustra similis Moravec et Van As, 2004, Atractidae gen. sp. (only female) (both Cosmocercoidea), Cucullanus sp. (only female) (Seuratoidea), Cithariniella longicaudata sp. n., Synodontisia annulata sp. n. (both Oxyuroidea), Contracaecum sp. third-stage larvae, third-stage larvae of Galeiceps sp. (both Ascaridoidea) and Eustrongylides sp. fourth-stage larvae (Dioctophymatoidea). The new species Citharinella longicaudata (type host Schilbe intermedius Rüppel) is mainly characterised by the shape and size of cephalic papillae and the spicule 108 µm long, and Synodontisia annulata (type host S. intermedius) by the shape of cephalic papillae, body length of gravid females (4.88-5.33 mm) and a short spicule (66 µm long). The female specimen of Cucullanus sp. from Tilapia sparmanni Smith markedly differs from congeners parasitising inland fishes in Africa by the elongate pseudobuccal capsule and by the excretory pore far posterior to the oesophago-intestinal junction; apparently, it belongs to an undescribed species. Galeiceps larvae parasitising fishes are described for the first time. This paper is a continuation of these studies, based on the same nematode collection, now providing results of the systematic evaluation of nematodes of the orders Ascaridida, Oxyurida and Enoplida. Detailed morphological examinations (using both light and scanning electron microscopy) of these materials revealed the presence of several species, including three new taxa of adults and previously undescribed larvae of a little-known anisakid genus. The results are presented herein. MATERIALS AND METHODSA total of 169 specimens belonging to nine fish species of the families Alestidae, Cichlidae, Clariidae, Mochokidae and Schilbeidae were collected in the Okavango River (mainstream in the Shakawe area) in the Panhandle, by gill nets, cast-nets and electro-fishing. Fish were taken live to a nearby field laboratory and maintained unfed in plastic tanks for at least two days to allow the gut to empty. The fish were anaesthetised and killed using MS222 and the internal organs were removed and placed in 1% saline. Nematodes removed from the digestive tract and viscera were fixed in 4% or 10% buffered neutral formalin.For light microscopical examination, the nematodes were cleared gradually in glycerine. Drawings were made with the aid of a Zeiss microscope drawing attachment. Specimens used for scanning electron microscopy (SEM) were post-fixed in 1% osmium tetroxide (in phosphate buffer), dehydrated through a graded ethanol series, critical-point-dried and sputter-coated with gold; they were examined using a JEOL JSM-7401F scanning electron microscope at an accelerating voltage of 4 kV (GB low mode). All measurements are in micrometres unless otherwise indicated. Only small numbers of the available s...

Section: Seuratoidea Hall 1916mentioning

confidence: 99%

Studies on ascaridid, oxyurid and enoplid nematodes (Nematoda) from fishes of the Okavango River, Botswana

2015

Folia Parasitologica

“…from A. glossodonta is the first known representative of this genus parasitizing marine fishes in Oceania. The species Spinitectus palawanensis Schmidt et Kuntz, 1969, described from Euthynnus affinis (Cantor) (reported as E. yaito) off the nearby Philippines (Schmidt and Kuntz 1969), was later synonymized with Prospinitectus mollis (Mamaev, 1968) (see Petter 1979).…”

Section: Commentsmentioning

confidence: 99%

Two cystidicolids (Nematoda, Cystidicolidae) from marine fishes off New Caledonia

Justine

2009

Acta Parasitologica

Two nematode species of the family Cystidicolidae were collected from the digestive tract of marine fishes off New Caledonia, South Pacific: Ascarophis adioryx Machida, 1981 from the stomach of the speckled squirrelfish Sargocentron spiniferum and the sabre squirrelfish Neoniphon sammara (new host record) (both Holocentridae, Beryciformes), and a Spinitectus sp. female, morphologically similar to S. beaveri Overstreet, 1970, from the roundjaw bonefish Albula glossodonta (Albulidae, Albuliformes). Based on light and scanning electron microscopy examinations, A. adioryx is redescribed and a new subgenus Dentiascarophis subgen. nov., characterized by the presence of one dorsal and one ventral median protrusions in the mouth, is established to accommodate it; a key to subgenera of Ascarophis is provided. Ascarophis holocentri Parukhin, 1984 is considered a junior synonym of A. adioryx. The cephalic structure of Spinitectus sp. and S. beaveri is very different from those in other congeners and, therefore, a new subgenus Paraspinitectus subgen. nov., characterized by highly reduced pseudolabia, is erected to accommodate these species. The hemiurid digenean Lecithochirium cirrhiti (Manter et Pritchard, 1960)

“…of the Mekong River in Laos female nematodes morphologically similar to S. petrowi and S. thaiensis (designated as Prospinitectus sp. ), but, mainly based on the presence of a very short vestibule, they erroneously assigned them to the genus Prospinitectus Petter, 1979. However, the principle differentiating features of Prospinitectus from Spinitectus are the complete absence of a vestibule and the presence of a small apical projection on each simple pseudolabium (see Petter 1979).…”

Section: Family Cystidicolidae Skryabin 1946mentioning

confidence: 99%

“…), but, mainly based on the presence of a very short vestibule, they erroneously assigned them to the genus Prospinitectus Petter, 1979. However, the principle differentiating features of Prospinitectus from Spinitectus are the complete absence of a vestibule and the presence of a small apical projection on each simple pseudolabium (see Petter 1979). Prospinitectus [type species P. mollis (Mamaev, 1968), a parasite of tuna fishes -see Mamaev 1968; Schmidt and Kuntz 1969;Petter 1979] was considered a valid genus by Moravec (2007).…”

Section: Family Cystidicolidae Skryabin 1946mentioning

confidence: 99%

“…However, the principle differentiating features of Prospinitectus from Spinitectus are the complete absence of a vestibule and the presence of a small apical projection on each simple pseudolabium (see Petter 1979). Prospinitectus [type species P. mollis (Mamaev, 1968), a parasite of tuna fishes -see Mamaev 1968; Schmidt and Kuntz 1969;Petter 1979] was considered a valid genus by Moravec (2007). Therefore, the above-mentioned nematodes from Laos as well as S. petrowi and S. thaiensis belong to Spinitectus as presently diagnosed.…”

Section: Family Cystidicolidae Skryabin 1946mentioning

confidence: 99%

See 1 more Smart Citation

Observations on two nematode species parasitizing freshwater fishes in Thailand, including Spinitectus thaiensis sp. nov. (Cystidicolidae) from Pseudomystus siamensis (Bagridae)

Yooyen

2011

Acta Parasitologica

One new and one already known species of parasitic nematodes are described from the intestine of freshwater fishes in Chiang Mai Province, northern Thailand: Spinitectus thaiensis sp. nov. (Cystidicolidae) from the catfish Pseudomystus siamensis (Regan) (Bagridae, Siluriformes) in the Fang Brook, a tributary of the Kok River (the Mekong River basin), Fang District and Oceanicucullanus chitwoodae Le- Van-Hoa et Pham-Ngoc-Khue, 1971 (Cucullanidae) from the cyprinid Mystacoleucus marginatus (Valenciennes) (Cyprinidae, Cypriniformes) in the Ping River (the Chao Phraya River basin), Muang District. The new species, S. thaiensis, is very similar to S. petrowi Belous, 1965, differing from it, in addition to some biometrical differences, mainly in having simple cuticular spines (instead of transversely oriented peg-like spines with rounded ends) on the ventral surface of the female tail; the spicules are 156-171 and 66-72 µm long, the vulva is situated at 74% of female body length, and the entire oesophagus including the vestibule represents 14-15% of body length in the male and 12% in the female. The latter species, O. chitwoodae, was studied for the first time by scanning electron microscopy, which enabled to recognize some previously unrecorded morphological details in this species. The finding of O. chitwoodae in M. marginatus in Thailand represents new host and geographical records for this nematode.