A new species of <Emphasis Type="Italic">Chitwoodiella</Emphasis> Basir, 1948 with first report on <Emphasis Type="Italic">Mirzaiella asiatica</Emphasis> Basir, 1942 (Nematoda,Travassosinematidae) from Manipur,North-East India

Chitwoodiella longicardia sp. nov. is characterized by having modified cardia into a long tubular structure and extends upto anterior portion of the intestine. This character is present in all the specimens collected from North-East India and represents the third species described under the genus globally. A short note on Mirzaiella asiatica Basir, 1942 is also given. Moreover, key to known species of Chitwoodiella and Mirzaiella are also provided. A comparative measurement table of known species of Chitwoodiella and Mirzaiella are given in Table I and Table II.     

Evidence for the occurrence of respiratory electron transport in adult Brugia pahangi and Dipetalonema viteae

Mixed-sex adult stages of Brugia pahangi and Dipetalonema viteae, in the absence of exogenous substrate, consumed oxygen at rates of 4.18 +/- 0.38 and 2.12 +/- 0.20 ngatoms O2 min-1 mg-1 dry wt. respectively. When calculated on a unit dry weight basis the endogenous O2 consumption rates (E-QO2) of mature adult male macrofilariae of B. pahangi and D. viteae were significantly greater than those of mature females, although the E-QO2 calculated per individual worm was essentially similar irrespective of sex. When assayed as separate unisexual groups, the oxygen uptake of male and female macrofilariae of both species was inhibited by classical inhibitors of respiratory electron transport (RET), and showed classical substrate bypass phenomena in response to succinate and ascorbate, N,N,N',N'-tetramethyl-p-phenylenediamine with respect to the RET inhibitors rotenone (inhibitor of complex I) and antimycin A (inhibitor of complex III). Since male worms elicited similar responses to the classical RET inhibitors as did mixed-sex and/or adult female populations, the possibility that developmental stages contained within the female filariids were contributing in any significant manner to the overall responses observed with the RET inhibitors can be discounted. Such responses as observed with live-intact macrofilariae are normally elicited only by mitochondrial preparations and suggest that the cuticles of both species are permeable to rotenone, succinate, antimycin A, N,N,N',N'-tetramethyl-p-phenylenediamine, azide and cyanide. The uncoupler 2,4-dinitrophenol stimulated the endogenous rate of oxygen consumption (E-QO2) of intact B. pahangi at 33-160 microM, indicating the probable occurrence of RET-coupled oxidative phosphorylation. Higher concentrations of 2,4-dinitrophenol proved inhibitory. Respiratory studies on subcellular fractions substantiated the responses elicited by the intact parasites, suggesting the presence of antimycin A-sensitive and -insensitive RET pathways capable of utilising alpha-glycerophosphate, succinate, and malate as substrates. Both B. pahangi and D. viteae macrofilariae therefore probably possess branched RET-pathways bifurcating on the substrate side of RET-complex III. The rates of substrate oxidation in terms of QO2 mg-1 mitochondrial protein compare well with those observed with other nematode parasites.     

Interaction between the severity of the infection by the nematode <Emphasis Type="Italic">Anguillicola crassus</Emphasis> and the tolerance to hypoxia in the European eel <Emphasis Type="Italic">Anguilla anguilla</Emphasis>

An experiment was conducted to test the effect of the infection by the swimbladder nematode Anguillicola crassus on the survival of the European eel Anguilla anguilla when exposed to hypoxic conditions. Forty-four wild caught and naturally infected eels were placed in an aquarium filled with water from the fishing site (Vaccarès Lagoon, French Mediterranean coast). In this confined environment (271), under decreasing oxygen resources, the first eel death occurred after 45 h (O₂ = 0.98 mg l⁻¹) and the last one after 96 h (O₂ = 0.48 mg l⁻¹). After dissection and parasite examination, analyses revealed significant negative correlations between the time to death and various parameters of parasite pressure (e.g., number of lumen worms, parasite mass, health state of the infected organ). It was shown that the severity of damage to the swimbladder rather than the count of living parasites was the major contributing factor in explaining the variation in time to death. These semi-experimental data demonstrating an increased eel mortality rate under severe oxygen stress are discussed for their relevance under field conditions, especially during hot summer months.     

Further description of <Emphasis Type="Italic">Aspidodera raillieti</Emphasis> (Nematoda: Aspidoderidae) from <Emphasis Type="Italic">Didelphis marsupialis</Emphasis> (Mammalia: Didelphidae) by light and scanning electron microscopy

Nematodes of the family Aspidoderidae (Nematoda: Heterakoidea) Freitas 1956 are widely distributed from Americas. The species of the genus Aspidodera Railliet and Henry 1912 are parasites of mammals of the orders Edentata, Marsupialia, and Rodentia. In the present work, Aspidodera raillieti (L. Travassos, Mem Inst Oswaldo Cruz 5(3):271-318, 1913), collected from the large intestine of Didelphis marsupialis (Mammalia: Didelphidae) from Valle del Cauca, Colombia, is redescribed. The association of light and scanning electron microscopy (SEM) allowed a detailed analysis of the morphology and ultrastructure of this nematode. Some taxonomic features, such as cephalic region, topography of the cuticle, sucker, spicules, posterior end of males, localization of vulva, the anus, and posterior end of females were observed. Important structures such as amphid, details of cephalic region, phasmid, and number and localization of caudal papillae are documented by SEM, for the first time adding characters to identify this species. Colombia is a new geographical record for A. raillieti.     

Redescription of <Emphasis Type="Italic">Decorataria decorata</Emphasis> (Spirurida,Acuariidae) based on nematodes from <Emphasis Type="Italic">Podiceps cristatus</Emphasis> and <Emphasis Type="Italic">P. grisegena</Emphasis> (Aves,Podicipediformes) from Bulgaria

Decorataria decorata (Cram, 1927) is redescribed on the basis of light-microscopy and SEM observations on specimens collected from the stomach of Podiceps cristatus and P. grisegena from Bulgaria. The SEM study revealed the presence of a porebearing field on each pseudolabium and a pair of spines (one dorsal and one ventral) situated between bases of the cordons. The deirids are spine-like and minute. The light-microscopy examination showed the presence of ornamentation situated under the dorsal surface of caudal alae. The occurrence of D. decorata in Bulgaria is a new geographical record.     

A new species of genus <Emphasis Type="Italic">Hysterothylacium</Emphasis> Ward et Magath, 1917 (Nematoda,Anisakidae) from <Emphasis Type="Italic">Liparis tanakae</Emphasis> (Scorpaeniformes,Liparidae) from the Yellow Sea,China

A new anisakid nematode, Hysterothylacium liparis sp. nov., is described from the intestine and stomach of the fish, Liparis tanakae (Gilbert et Burke, 1912) (Scorpaeniformes, Liparidae), a fish endemic to the Yellow Sea, China. The new species can be distinguished from the congeners by the absence of lateral alae, the length of the intestinal caecum (1.94–3.35 mm, 58.84–82.47% of oesophageal length), the number and arrangement of the caudal papillae (20–29 precloacal subventral pairs, 1 adcloacal pair and 4 postcloacal pairs), the size of the spicules (1.94–3.74 mm, 4.85–7.30% of body length) and the morphology of the tail tip. This is the first species of adult ascaridoid nematodes to be reported from fishes of the family Liparidae in northern China.     

A new species of <Emphasis Type="Italic">Oxyascaris</Emphasis> (Nematoda,Cosmocercidae) in the Costa Rica brook frog, <Emphasis Type="Italic">Duellmanohyla uranochroa</Emphasis> (Anura,Hylidae)

Oxyascaris mcdiarmidi sp. nov. (Nematoda, Cosmocercidae) from the small intestine of Duellmanohyla uranochroa from Costa Rica is described. Oxyascaris mcdiarmidi sp. nov. represents the 4th species assigned to the genus and is distinguished from congeners by the distribution pattern of the caudal papillae of the male, spicule length and vulvar position.     

Long-term variation in an occurrence of Rhabditis orbitalis parasitic larvae (Nematoda, Rhabditidae) in the eyes of montane rodents

Summary During a long-term survey (1999–2005) of parasitic larvae of nidicolous nematode Rhabditis orbitalis Sudhaus et Schulte, 1986 in the West Tatra Mts, the nematodes were detected in the eye orbits of snow voles Chionomys nivalis in 1999, 2004 and 2005. In the last year, R. orbitalis was detected also in another vole species Clethrionomys glareolus and Microtus tatricus both in previously studied site and in the Low Tatra Mts, however, it has never appeared at other rodent species. For the first time, an irregular occurrence of the R. orbitalis parasitic larvae has been ascertained in natural conditions of the Slovak mountains. The eye nematodes occurred only during autumn or cold and rather wet summer months, when density of the preferred host Ch. nivalis was relatively low. A hypothesis has been put forward that an occasional appearance of parasitic eye larvae in the life cycle of bacteriophagous R. orbitalis represents a strategy for surviving periods of a scarcity of bacterial food, which could be influenced by a combination of weather conditions, density of host rodents and seasonal abundance of R. orbitalis in rodent nests.