Redescription of two nematode parasites infecting Reptilia in Qena Governorate

During a helminthological examination of Tarentola annularis (Geoffroy, 1828) and Chalcides ocellatus (Forskal, 1775), 12 out of 60 Tarentola annularis were found to harbour a large number of Spauligodon aspiculus, 30 out of 106 Chalcides ocellatus were found to harbour Thelandros aegypti.


INTRODUCTION
The genus Spauligodon was established when Pharyngodoninae, Travassos, 1919 was revised.Skrjabin et al., (1960) retained Pharyngodon Diesing 1861, Parathelandros Baylis, 1930 andestablished Spauligodon Skrjabin, Schikhobalova andLagodovskaja, 1960.They also placed the remaining genera in the Oxyuridae or Ozolaimidae.Chabud and Brygoo in 1962 suggested that the most important factor in speciation of reptilian oxyurids would be the geographical distribution.Bursey and Goldberg (1995) stated that the species of Spauligodon can be separated on the basis of presence or absence of the spines on the tail of female and the shape of eggs.

MATERIALS AND METHODS
60 speciemens of Tarentola annularis and 106 specimens of Chalcides ocellatus were collected from Qena Governorate.The body cavity was opened and the gastrointestinal tract was removed by cutting across the oesophagus and rectum.The oesophagus, stomach, small intestine and large intestine of each host were examined separately for parasites.Nematodes were placed in glycerol, allowed to clear and examined under light microscope.

RESULTS AND DISCUSSION
Spauligodon aspiculus (Fig. 1 and 2) General: Small nematodes; body tapering at both ends.The excretory pore is below the level of the oesophageal bulb.The oesophagus ends in valvulate, subspherical bulb which separated from oesophagus body by small constriction.The posterior part of tail is elongated, smooth and forms a thin needle-like projection.
Male: Small, white, fusiform nematodes; body tapering at both ends: length 1.51 mm (0.96-2.6 mm); width at level of excretory pore 0.16 mm (0.13-0.17 mm).Two lateral cuticular alae extend a long body, anteriorly initiating slightly infront of nerve ring level and posteriorly reaching to cloaca.The alae are well expand near the posterior end of body.They measures about 0.02-0.29 mm in width and 0.09-0.11mm in length.The oesophagus is cylindrical in shape and measures about 0.35 (0.32-0.39 mm) in length (including bulb), the distance of excretory pore from the anterior end is 0.65 (0.60-0.71 mm).The tail is provided with well developed membranous expansion called the caudal alae.The tail is filiform and extends beyond postcloacal papillae.It measures about 0.14 (0.11-0.2 mm) in length and the spicule is absent.There are three pairs of genital papillae, not all included in caudal alae.The first pair is preanal and formed from small sessile papillae.The second one is the first of the postanal pairs and situated near the posterior end of caudal alae.The second postanal pair is formed a large pedunculated papillae and situated immediately below forgoing pair.
Female: Small, white, fusiform nematodes; body tapering at both ends: length 3.36 (2.98-3.75mm), width 0.22 (2.98-3.75mm).The lateral cuticular alae are absent.The oesophagus is cylindrical in shape and measures about 0.46 (0.44-0.47 mm) in length.The excretory pore is slightly below the level of the oesophageal bulb and the distance from the anterior end is 0.57 (0.54-0.5 mm).The vulva is situated a short distance below the excretory pore and the distance from the anterior end is 0.61 (0.57-0.63 mm).The tail is conical, 0.4 (0.39-0.40 mm) in length and the filamentous part with no spines.The vagina is a well developed musculated tube.The ovaries are situated at the posterior half of the body.The egg is oval in shape, having a thin shell and measures 122-140 µm in length and 54-62 µm in width.Bursey and Goldberg (1995) stated that the species of Spauligodon can be separated on the basis of presence or absence of the spines on the tail of female and the shape of eggs.
The total absence of male spicule aligns the species under discussion with three other species of Spauligodon which are known to occur in reptiles.These species are Spauligodon caymanensis Bursey and Goldberg, 1995.Spauligodon hemidactylus Bursey and Goldberg, 1996 and Spauligodon petersi Bursey et al., 1997.Nevertheless, there are a substantial differences between the present species and both of S. caymanensis and S. hemidactylus.These differences can be summarized as follows: The present worm has 3 rounded lips but S. caymanensis and S. hemidactylus have 3 bilobed lips.
The present nematode has no spines on the tail of both males and females, but the tail of S. caymanensis and S. hemidactylus are provided with spines.
There are mensural variations between the present species and both of S. caymanensis and S. hemidactylus.The absence of cuticular spines on the tail of female is a characteristic feature binding the present species with S. vojteki Moravec et al., 1987, S. gehyrae Bursey and Goldberg, 1996and S. petersi Bursey et al., 1997.S. gehyrae differs from the present species by the possession of male spicule, bilobed lips and the mensural variations.However S. petersi differs from the present species in the shape of lips and the mensural variation.By comparing the present species with S. vojteki Moravec et al., 1987, it is clear that the present parasite is closed to S. vojteki in its measurements.Moravec et al., (1987b) reported that S. vojteki is characterized by: three bilobed lips, the presence of male spicule and the egg width was 48-51 µ m.
However, the present species differs from S. vojteki by having 3 rounded lips and absence of male spicule.Moreover, the egg width of the present species is 54-62 µm.Thelandros aegypti (Fig. 3, 4) General: Small nematodes; body tapering at both ends.The oesophagus is cylindrical and ending by a well developed bulb.The body is transversely striated and this striation of cuticle is extending from the cephalic collarette to the posterior end.
Male: Small, white; body tapering at both ends: length 3.2 (2.85-3.6 mm); width 0.28 (0.24-0.32 mm).The length of oesophagus (including bulb) is 0.56 (0.48-0.65 mm).The testes are situated at the midbody.The male tail is narrow and it ' s length is 0.03-0.05mm.Lateral alae is near the level of oesophageal isthmus.There are 3 pairs of anal papillae, the first and the second are pre and perianal.The last pair is situated at the mid point of dorsal projection.There is a single slender spicule, the distal end of this spicule is rounded and is 0.062-0.067mm in length.
Female: The body length is 4.25 (3.65-4.85mm); width 0.30 (0.25-0.36 mm).The length of oesophagus is 0.87 (0.76-0.98 mm).The vulva is post-equatorial and the distance of vulva from the anterior end is 2.4 (2.1-2.7 mm).The anterior ovary extends to the level of excretory pore and the posterior ovary extends posteriorly to the anal opening.The two uteri are opposed and the eggs are oval in shape.The egg is 78.69-84.27μm long and 51.34-68 μm wide.Walton (1941) reviewed the geographical and host distribution of genus Thelandros.He pointed out that the majority of the known species are from North Africa.However, a few species were reported from Asian, South American hosts and one from Australia.Walton (1941) described legless lizard and the female of Thelandros sp. from California.Read and Amrein in 1951 stated that the genus Thelandros consists of twenty three described species.Twety-two of them have been described from reptiles and one from an amphibian Skrjabin et al., (1960) reported that the presence or absence of lateral alae has a great importance to separate the genus, Thelandros wedi, 1861 and Parapharyngodon Chatterji, 1933.Several subsequent authors accepted their suggestion.Adamson (1981) redefined Parapharyngodon and Thelandros and distinguished them on the basis of male and female caudal morphology and egg structure.He also reported that Parapharyngodon spp.were found in insectivorous reptiles and amphibians, where Thelandros spp.are essentially parasites of herbivorous and omnivorous reptiles.Adamson and Nasher (1984b) described the pharyngodonid nematode, Thelandros popovi Markov and Bogdanov, 1963 from the posterior intestine of Agama adramitana in Saudi Arabia.Gupta and Duggal (1989) described Thelandros baylist chatterji, 1935 from the intestine of rock lizard, Agama hemalayana in Amerein, 1951.While T. californiensis male possesses 4 pairs of anal papillae, the present species and all closely related species have only 3 pairs of male anal papillae.
By comparing the present material with T. bicaudantus, T. minutus, T. baylisi and T. popovi, it is clear that the present species has some similarity to both T. popovi and T. baylisi due to the presence of caudal alae in all.However, the present nematode differs from T. popovi in the following:  The oral opening of the present worm is surrounded by 3 lips but T. popovi has no lips. The clear mensural variations between them. The host and locality.