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The ecological integrity of freshwater ecosystems is regularly examined through assessment of their macroinvertebrate assemblages. The various methods used in such biomonitoring all have one characteristic in common – the neglect of water mites. Even though this group perfectly fulfills all necessary requisites for successful bioindicators, these invertebrates are either completely ignored or lumped together as “Acari”. This study, for the first time, uses water mites (Hydrachnidia) as bioindicators in the Neotropics to compare the anthropogenic stress in 15 streams at three different levels of contamination (pristine, rural, urban). In total, 4371 water mite specimens, belonging to 31 genera and 14 families, were collected. Diversity, abundance, and richness of water mite assemblages were significantly reduced with increasing levels of contamination. These differences were clearest in the dry season. Atractidella turned out to be, by far, the most tolerant water mite genus, having the greatest abundance at the most contaminated sites. In contrast, Pseudotorrenticola was found only in pristine waters, while Hydrodroma , Limnesia , Koenikea , Torrenticola, Monatractides and the family Aturidae showed clear preferences for pristine waters. Our data show, that water mites, identified to genus level, are well suited for water quality assessment in neotropical lowland streams, clearly distinguishing different levels of contamination/anthropogenic stress. [ABSTRACT FROM AUTHOR]

Abstract: Adults and deutonymphs of a new water mite species of the genus Hygrobates Koch, 1837 (Acari, Hydrachnidia, Hygrobatidae) were found to parasitize the Hong Kong Newt, Paramesotriton hongkongensis Myers and Leviton, 1962 (Amphibia, Caudata, Salamandridae), endemic to Hong Kong and coastal areas of Guangdong Province: Hygrobates aloisii sp. nov. Males and females, as well as deutonymphs and larvae are described. A new subgenus –Lurchibates subgen. nov. – is defined to accommodate the species of the Hygrobates salamandrarum-group. The parasite–host association, infestation rate, attachment sites and the impact of mite infestation on the newts behaviour and body condition are investigated. These ecological aspects of the parasite–host association between freshwater mites and newts are examined for the first time in detail in their natural habitat. [Copyright &y& Elsevier]

Abstract: Two new water mite species of the genus Hygrobates Koch, 1837 (Acari, Hydrachnidia, Hygrobatidae) were found to live parasitic on newts of the genus Paramesotriton Chang, 1935 (Amphibia, Caudata, Salamandridae) from Vietnam and Laos: Hygrobates forcipifer sp. nov. and H. ancistrophorus sp. nov. The H. salamandrarum-group is defined, that now includes three species from Southeast Asia. Males and females of both new species are described, as well as larvae and deutonymphs of the Vietnamese species. These data provide the first record of males, nymphs and larvae of the species-group. The systematic position of the group, as well as the parasite–host association and the lifecycle of the species are discussed. Furthermore, the character states of the striking mouthparts, particularly modified as an adaptation for penetrating the amphibian skin, the genital skeleton and the larval morphology are examined. [Copyright &y& Elsevier]

In this study we present the results from field work in northern Vietnam regarding the occurrence of the warty newt species Paramesotriton deloustali and P. guangxiensis in disturbed and undisturbed habitats and the presence of parasitic water mites of the genus Hygrobates (sg. Lurchibates) (Acari, Hydrachnidia). We report the first evidence of mite parasitism in P. guangxiensis and analyze differences in the infestation rates between both Paramesotriton species and habitat qualities. Furthermore we present the first indication of the detrimental effects of these parasite-host interactions. Our preliminary assessment seems to support the sensitivity of P. guangxiensis to habitat disturbances, as the average number of captured newts per stream was twice as high in undisturbed habitats as in disturbed ones. Until now a very specific parasite-host association was supposed between water mite and newt species. However, our results show the first evidence of a water mite species of the subgenus Lurchibates (Hygrobates forcipifer) parasitizing more than one host species, in this case not only P. deloustali (already known) but also P. guangxiensis (new record). The overall infestation rate was 27 % for P. deloustali and 71 % for P. guangxiensis , from which 100 % and 77 % of the mite-incidence occurred in undisturbed habitats, respectively. Furthermore the parasite load of the newts was clearly higher in prime quality streams: the parasite load in undisturbed habitats was very similar between P. deloustali (19.64 mites per newt) and P. guangxiensis (20.13 mites per newt), however it was significantly lower for P. guangxiensis in disturbed habitats (8.86 mites per newt). Future research should bring more detail on these parasite host associations, especially on the effect of parasitism on the newts. Warty newts are already threatened due to their shrinking natural habitat and overharvesting. We report the first concerns that mite parasitism might be a critical additional stress factor in undisturbed habitats. [ABSTRACT FROM AUTHOR]

Abstract: Earlier publication suggested that IgG2a and IgG2c (coding for Igh-1a and Igh-1b) are organized in tandem on the same chromosome as two distinct loci in mice. Our data suggest that IgG2a and IgG2c are not physically linked on the chromosome and are allelic – single locus in majority strains of mice. In another word, IgG2b–IgG2c–IgG2a haplotype proposed by may exist in some strains of mice, but IgG2b–IgG2a and IgG2b–IgG2c are likely to be most common haplotypes in mice. Therefore, inbred mice may produce different IgG2a isotypes dependent on their origin (strain); C57B/6 and SJL mice secrete IgG2c while NMRI and DBA/2 mice secrete IgG2a only. The situation is more complicated for Swiss Webster mice (outbred) and Alzheimer''s disease transgenic (AD/Tg) mice with multi-genetic backgrounds; mice may secrete only IgG2a, or IgG2c, or both IgG2a and IgG2c. IgG2a and IgG2c likely have different immune profile (response, immune-decoration) in mice due to their divergence of protein sequence. If antibodies based on IgG2a (or IgG2c) are used in chronic studies for preclinical evaluation of antibody efficacy, characterization of IgG2a isotypes in advance becomes critical in the design of such biopharmaceutical projects in order to avoid immune response. [Copyright &y& Elsevier]