Zuzana Čadková

Aquarium hitchhikers: attached commensals imported with freshwater shrimps via the pet trade.

The keeping of home aquaria is one of the most popular hobbies globally. In contrast to the ornamental fish trade, decapod crustaceans such as shrimps, crayfish and crabs are relatively new to the pet trade. Nevertheless, the popularity of ornamental shrimp in freshwater aquaria has rapidly increased in recent years. Indonesia is one of the leading producers and exporters of ornamental aquatic animals globally and the Czech Republic is a gateway for these animals into the European Union territory. The pathway for introductions of organisms unintentionally moved in association with ornamental shrimps via the international trade has to date not been evaluated. We examined a small number of shrimps imported from Indonesia into the Czech Republic in May 2015 and found large numbers of the protozoan Vorticella sp., one species of scutariellid temnocephalidan (Caridinicola sp.), and one species of bdelloid rotifer, associated with two species of atyid shrimps, indicating an invasion risk from fauna carried unintentionally by this vector. Although our observations were limited in scale, we estimate the total number of commensal fauna imported into the Czech Republic with ornamental shrimps via the pet trade to be in the order of hundreds of thousands per month. As attached organisms can directly or indirectly cause diseases in certain species of decapod crustaceans, we recommend five steps to reduce risks of introduction of “hitchhikers” to aquaria and wildlife.

Intestinal Parasite Acanthocephalus lucii (Acanthocephala) from European Perch (Perca fluviatilis) as a Bioindicator for Lead Pollution in the Stream “Jevanský potok” Near Prague, Czech Republic

Lead concentrations in the tissues of perch and its parasites were determined as mg/kg dw. Lead was found at higher concentrations in the acanthocephalans (11.56) than in different tissues (liver, gonads and muscle with skin and bone) of perch. With respect to fish tissues, the highest concentrations of lead were present in the liver (1.24), followed by the gonads (0.57) whereas the lowest concentrations were in the muscle with skin and bone (0.21). The bioconcentration factors for lead indicated that parasites accumulate metals to a higher degree than fish tissues—lead concentrations in acanthocephalans were 9.32, 19.27 and 55.05 higher than in liver, gonads and muscles of host, respectively.

Concentrations of Zn, Mn, Cu and Cd in different tissues of perch (Perca fluviatilis) and in perch intestinal parasite (Acanthocephalus lucii) from the stream near Prague (Czech Republic)

We monitored concentrations of Cd, Cu, Mn and Zn in acantocephalan parasites (Acanthocephalus lucii) and its final host (Perca fluviatilis). The concentrations in parasites were found to be significantly higher than those found in the muscle, gonads and liver of fish host. The bioaccumulation factor values (BF=C(parasite)/C(host muscle)) were 194, 24.4, 2.2 and 4.7 for Cd, Cu, Mn and Zn, respectively. This suggests a benefit for the host due to the high accumulation of toxic cadmium.

Is the tapeworm able to affect tissue Pb-concentrations in white rat?

The effect of gastrointestinal helminths on Pb accumulation in the host body is ambiguous. A laboratory experiment with Rattus norvegicus/Hymenolepis diminuta model was conducted to determine Pb toxicokinetics in a terrestrial host-parasite system. The ET-AAS or ICP-OES techniques were used to determine Pb concentrations (CPb) in both tapeworms and host tissues (kidney, liver, bone, testes, muscle and intestinal wall). Concerning the entire host-parasite system, the highest CPb were detected in H. diminuta. Rat kidneys and bone were the only two tissues whose mean Pb levels were lower in parasitized animals than they were in non-infected subjects after both levels of exposure. At low Pb exposure, parasitization slightly changed the Pb toxicokinetics in the host body. However, with respect to tissue at the same exposure level, no significant differences were detected between the parasitized and non-parasitized animals and no significant correlations were found between CPb in tapeworms and those of host tissues. The results of this study indicate that H. diminuta does not protect rat from elevated Pb exposure even if tapeworm accumulates a higher portion of ingested Pb dose compared with that of the most Pb-loaded host soft tissue. The portion of Pb dose accumulated in H. diminuta correlates positively with parasite biomass.

Experimental studies on the cadmium accumulation in the cestode Moniezia expansa (Cestoda: Anoplocephalidae) and its final host (Ovis aries)

The tapeworm Moniezia expansa and naturally infected sheep were investigated with respect to their cadmium accumulation. Cadmium chloride (CdCl(2), 0.2 g) was added to 10 ml of distilled water and administered orally to the sheep every day for a period of 1 week. The cadmium content of M. expansa was lower than that in the liver tissues of sheep, although this difference was not significant. The highest mean cadmium concentrations were found in the liver of sheep infected with M. expansa (24.5+/-11.5 mgkg(-1) dry weight). The mean cadmium concentration measured in M. expansa was 21.5+/-19.2 mgkg(-1) dry weight, which was 31 and 1.5 times higher than levels determined in the muscle and kidney of the host, respectively, but 0.9 times lower than levels determined in the liver of host. Sheeps with M. expansa infection always had higher cadmium concentrations in the tissues (with the exception of the blood) than their uninfected conspecifics.

Endoparasites in European hares (Lepus europaeus) under gamekeeping conditions in the Czech Republic

SummaryDuring December 2007 and November–April 2008/2009, 128 gastrointestinal tracts and 1680 faecal samples of hares from different parts of the Czech Republic were examined. Evaluation of the faeces samples indicated that the samples could have been infected with any one of the following parasites: Eimeria spp., Trichostrongylus retortaeformis, Trichuris leporis, Graphidium strigosum, Strongyloides sp., Protostrongylus spp. and Anoplocephalidae tape-worms. Trichostrongylus retortaeformis was the most common nematode (75.8 %). 39.8 % of the animals were infected with Trichuris leporis. Only four hares were in-fected with Graphidium strigosum. Eimeria spp. was the most commonly occurring parasite (90.5 %). The follow-ing species were found: Eimeria coquelinae, E. cabareti, E. leporis, E. babatica, E. europea, E. pierrecouderti, E. macrosculpta, E. orbiculata and E. stefanski. Eimeria coquelinae was the most prevalent species (68.4 %). Eimeria cabareti and E. leporis were the next most frequently found species (64.5 % and 57.8 %, respectively).

Comparative morphological and molecular identification of Haemonchus species in sheep

SummaryA combined approach in the determination of Haemonchus nematodes from sheep was applied in this trial. Using selected morphological characters 90.2 % females and 84.2 % males of Haemonchus contortus and 9.8 % females and 15.8 % males of Haemonchus placei were identified. Although cluster analysis based on morphological identification clearly separated two Haemonchus species, H. contortus was exclusively detected in all specimens using restriction cleavage of the ITS-2 region with FspBI endonuclease as well as through the sequencing analysis. Because sheep from both farms have never had contact with other ruminants, and the farmers apply only closed flock turnover, we assume that only H. contortus mono-infection occurred on both farms. This opinion is also supported by molecular data. The most striking result of our study was the finding which indicates that the discriminant function is not able to accurately identify Haemonchus males at the species level.

Effect of Acanthocephalus lucii Infection on Total Mercury Concentrations in Muscle and Gonads of Fish Host (Perca fluviatilis)

The samples from 13 perches (Perca fluviatilis) – muscle with skin and bones; fish gonads; and acanthocephalan parasites were analysed for mercury (Hg). Hg concentrations were present in all analysed samples. There were found no statistically significant difference in Hg concentration in fish tissues between perches either with or without infection by the acanthocephalan parasite, Acanthocephalus lucii). In this study there was no evidence that acanthocephalan worms accumulate mercury from hosts. For this reason, A. lucii is not a suitable bioindicator for mercury pollution.

Competition for minerals (Zn, Mn, Fe, Cu) and Cd between sheep tapeworm (Moniezia expansa) and its definitive host sheep (Ovis aries)

SummaryConcentrations of various essential and toxic elements (Zn, Mn, Fe, Cu and Cd) were analysed by inductively coupled plasma optical emission spectrometry (ICP-OES) in the sheep tapeworm (Moniezia expansa) and in different tissues of its host Ovis aries. The element concentrations of the cestode parasites were compared to different organs (liver, kidney, and muscle) of sheep that were exposed to experimental amounts of Cd (0.2 g of CdCl2 added to 10 ml of distilled water and administered orally to the sheep every day for a period of 1 week). All sheep were randomly divided into four groups; the first group (Cd) contained uninfected, Cd exposed sheep, and its control (group C) were uninfected and unexposed to Cd; the second group (TCd) contained infected, Cd exposed sheep, and its control (group CT) contained infected, unexposed sheep. The experimental Cd exposure resulted in significantly higher Mn concentrations in sheep tapeworms (10.0 mg/kg) than in sheep muscle (0.6 mg/kg) and kidney (0.8 mg/kg). The experimental Cd exposure also significantly decreased the Cu concentrations in sheep liver and muscle. Moreover Cd exposure decreased the Fe concentrations in sheep kidney but caused it to increase in sheep liver and muscle. Zinc concentrations showed no differences between groups (Cd, TCd, C, T) in any monitored sheep tissues. The article also discuss the effect of tapeworm infection on a significant decrease of Fe in sheep muscle, liver and kidneys, as well as a decrease in Cu levels of the muscles and liver. This mineral imbalance may contribute to various health problems such as osteoporosis, metabolic processes disorder, antioxidant (SOD) dysfunction etc.

Efficacy and persistent activity of moxidectin against natural Muellerius capillaris infection in goats and pathological consequences of muelleriosis.

The effect of moxidectin against natural Muellerius capillaris infection in goats was evaluated in this study. Long-acting moxidectin at a single dose of 1 mg kg(-1) body weight was administered to an entire flock (n=10) of goats. The individual faecal larval count reduction was applied as an indicator of treatment efficacy. A significant reduction (>98%) in larval counts was observed in all surveyed animals 14 days after drug administration. Moxidectin demonstrated persistent activity in this study; the mean faecal larval count reduction was 99.1% ± 1.8 on day 77 of the treatment. Macroscopic abnormalities and histological changes in the lungs of two infected goats were evident during the post-mortem examination. The pathological consequences of M. capillaris infection were observed even three months after parasite elimination. The results of this study indicate that moxidectin is a highly effective anthelmintic agent for the control of muelleriosis in goats. This drug provides animals with fifteen weeks of protections against M. capillaris reinfection.