Turn the temperature to turquoise: cues for colour change in the male chameleon grasshopper (Kosciuscola tristis) (Orthoptera: Acrididae)

Rapid, reversible colour change is unusual in animals, but is a feature of male chameleon grasshoppers (Kosciuscola tristis). Understanding what triggers this colour change is paramount to developing hypotheses explaining its evolutionary significance. In a series of manipulative experiments the author quantified the effects of temperature, and time of day, as well as internal body temperature, on the colour of male K. tristis. The results suggest that male chameleon grasshoppers change colour primarily in response to temperature and that the rate of colour change varies considerably, with the change from black to turquoise occurring up to 10 times faster than the reverse. Body temperature changed quickly (within 10 min) in response to changes in ambient temperature, but colour change did not match this speed and thus colour is decoupled from internal temperature. This indicates that male colour change is driven primarily by ambient temperature but that their colour does not necessarily reflect current internal temperature. I propose several functional hypotheses for male colour change in K. tristis.     

Molecular Identification and Hidden Diversity of Novel Daphnia Parasites from European Lakes

Parasites play important roles in local population dynamics and genetic structure. However, due to insufficient diagnostic tools, detailed host-parasite interactions may remain concealed by hidden parasite diversity in natural systems. Microscopic examination of 19 European lake Daphnia populations revealed the presence of three groups of parasites: fungi, microsporidia, and oomycetes. For most of these parasites no genetic markers have been described so far. Based on sequence similarities of the nuclear small-subunit and internal transcribed spacer (ITS) rRNA gene regions, one fungus, four microsporidian, and nine oomycete taxa were discovered in 147 infected Daphnia (and/or three other zooplankton crustaceans). Additionally, cloning of rRNA gene regions revealed parasite sequence variation within host individuals. This was most pronounced in the ITS region of one microsporidian taxon, where the within-host sequence variation ranged from 1.7% to 5.3% polymorphic sites for parasite isolates from 14 different geographical locations. Interestingly, the parasite isolates from close locations grouped together based on sequence similarities, suggesting that there was parasite dispersal. Taken together, the data obtained in this study revealed hidden diversity of parasite communities in Daphnia lake populations. Moreover, a higher level of resolution for identifying parasite strains makes it possible to test new hypotheses with respect to parasite dispersal, transmission routes, and coinfection.During the last decade, microparasites of Daphnia species, which are small zooplankton crustaceans, have become a popular study system in ecological and evolutionary research (for a review, see reference 15). It has been shown both in the field and under controlled laboratory conditions that parasites have a substantial impact on Daphnia fitness (7, 21, 52). Parasite-induced reductions in Daphnia population density (11, 12) or even population crashes (17) might result in disruptions of aquatic food webs, as daphnids play important roles as main phytoplankton grazers and as a major food of planktivorous fish (27). Moreover, as infections are often genotype specific (6, 8), they can lead to changes in the gene pool of a Daphnia population (7, 14), sometimes significantly increasing the genetic diversity of the host population (12, 54). Thus, Daphnia parasites cause not only ecological but also evolutionary changes in aquatic systems.Conclusions regarding the importance of parasites in natural systems require powerful tools to detect and properly identify parasite taxa. Thus far, few species-specific molecular markers have been developed for Daphnia parasites (33, 38, 39, 41) and then used in experimental studies (3). In surveys of natural Daphnia populations, parasite identification has been based primarily on microscopic examination (4, 5, 29, 52), with only one exception (32). The parasites recorded in natural populations of Daphnia are thus considered members of certain taxa, or even species, without genetic confirmation. The fact that molecular markers are not used to characterize Daphnia infections makes it difficult to compare epidemic patterns across different habitats and/or various field surveys, as parasites cannot be unambiguously identified by microscopic examination alone. Even if microscopic identification is theoretically possible (for example, by examining ultrastructural morphology by electron microscopy [37]), this approach is not feasible for routine analysis. Consequently, classification of parasites that actually belong to different taxa in the same group might introduce noise into field surveys, as parasite taxa differ widely in virulence and host range (for a review, see reference 15).Most of the known Daphnia parasites that have been described were obtained from small temporary ponds and rock pools (4, 16, 43). In permanent lakes, lower parasite diversity was assumed, mainly because increased fish predation reduces the population density of potential hosts (18), whereas high host density is a crucial determinant of epidemic spread (1, 2, 45). In addition, infected Daphnia spp. are more vulnerable to fish that hunt visually due to loss of their transparent appearance (11, 13). On the other hand, it was recently shown that even if Daphnia host density was reduced by selective fish predation, the prevalence of infection did not decline, probably due to the very high rates of transmission of the parasite that was observed (11). In contrast, we expected that the highly heterogeneous biotic and abiotic conditions in permanent lakes (27) would provide a variety of niches (for a review, see reference 47), which also favor a high level of parasite diversity. Therefore, Czech canyon-shaped reservoirs were chosen as our main study systems, because in these lakes environmental gradients are particularly pronounced in both the horizontal and vertical dimensions (42). Moreover, the Daphnia communities of these reservoirs are dominated by members of the Daphnia longispina complex (35), taxa which have previously been shown to be infected by a variety of parasites (52).The results of our study revealed a high level of diversity of Daphnia parasites in permanent lakes. Fourteen different parasite taxa were detected using nuclear small-subunit (SSU) and internal transcribed spacer (ITS) rRNA gene sequence information. In addition, a high level of sequence variation was observed in the ITS region of one microsporidian taxon. Thus, molecular markers are now available which allow discrimination with high resolution among and within parasite taxa and provide tools to address more detailed questions concerning lake Daphnia-microparasite systems.     

Identification of an Apically-Located Antigen That Is Conserved in Sporozoan Parasites

ABSTRACT. Sporozoan parasites of the phylum Apicomplexa all possess common apical structures. The current study used a monoclonal antibody (mAb-E12) to identify a conserved antigen in the apical region of merozoites of seven species of Plasmodium (including rodent, primate and human pathogens), tachyzoites of Toxoplasma gondii , bradyzoites of Sarcocystis bovis , and sporozoites and merozoites of Eimeria tenella and E. acervulina. The antigen was also present in sporozoites of haemosporinid parasites. Immunofluorescence studies showed that the antigen was restricted to the apical 3rd of these invasive stages. Using immunoelectron microscopy, labeling was demonstrated in the region of the polar ring, below the paired inner membranes of the parasite pellicle, and near the subpellicular microtubules radiating from the polar ring of merozoites and sporozoites of E. tenella . The majority of the antigen could be extracted with 1% Triton-X 100, but a portion remained associated with the cytoskeletal elements. The molecule has a relative rate of migration (M_r) of 47,000 in Plasmodium spp. and 43–46,000 in coccidian species. Since the epitope recognized by mAb-El 2 is highly conserved, restricted to motile stages, and appears to be associated with microtubules, this antigen could be involved in cellular motility and cellular invasion.     

Molecular Identification of Adult and Juvenile Linyphiid and Theridiid Spiders in Alpine Glacier Foreland Communities

In glacier forelands spiders constitute a large proportion of the invertebrate community. Therefore, it is important to be able to determine the species that can be found in these areas. Linyphiid and theridiid spider identification is currently not possible in juvenile specimens using traditional morphological based methods, however, a large proportion of the population in these areas are usually juveniles. Molecular methods permit identification of species at different life stages, making juvenile identification possible. In this study we tested a molecular tool to identify the 10 most common species of Linyphiidae and Theridiidae found in three glacier foreland communities of the Austrian Alps. Two multiplex PCR systems were developed and over 90% of the 753 field-collected spiders were identified successfully. The species targeted were found to be common in all three valleys during the summer of 2010. A comparison between the molecular and morphological data showed that although there was a slight difference in the results, the overall outcome was the same independently of the identification method used. We believe the quick and reliable identification of the spiders via the multiplex PCR assays developed here will aid the study of these families in Alpine habitats.     

Plant Finding and Acceptance Behaviors of Anasa tristis (DeGeer)

Finding and acceptance behaviors of Anasa tristis were investigated using plants that are suitable (pumpkin) or unsuitable (cucumber, coleus) for development. A. tristis found plants in the absence of non-contact cues. Plant finding is enhanced by olfaction and vision. A. tristis found suitable and unsuitable plants equally well. The importance of olfaction in plant acceptance is suggested by intense antennation while on plant and change in behavior on pumpkin and coleus after removal of antennae. Insects on suitable and unsuitable plants dab the surface, contact the plant surface with the labium and insert stylets. Post ingestive effects are important for plant acceptance and rejection. Ingesting water and some nutrients from plants unsuitable for development can be important in extending the time available to move between resource patches.     

Identification of the Sex Pheromone of the Tree Infesting Cossid Moth Coryphodema tristis (Lepidoptera: Cossidae)

The cossid moth (Coryphodema tristis) has a broad range of native tree hosts in South Africa. The moth recently moved into non-native Eucalyptus plantations in South Africa, on which it now causes significant damage. Here we investigate the chemicals involved in pheromone communication between the sexes of this moth in order to better understand its ecology, and with a view to potentially develop management tools for it. In particular, we characterize female gland extracts and headspace samples through coupled gas chromatography electro-antennographic detection (GC-EAD) and two dimensional gas chromatography mass spectrometry (GCxGC-MS). Tentative identities of the potential pheromone compounds were confirmed by comparing both retention time and mass spectra with authentic standards. Two electrophysiologically active pheromone compounds, tetradecyl acetate (14:OAc) and Z9-tetradecenyl acetate (Z9-14:OAc) were identified from pheromone gland extracts, and an additional compound (Z9-14:OH) from headspace samples. We further determined dose response curves for the identified compounds and six other structurally similar compounds that are common to the order Cossidae. Male antennae showed superior sensitivity toward Z9-14:OAc, Z7-tetradecenyl acetate (Z7-14:OAc), E9-tetradecenyl acetate (E9-14:OAc), Z9-tetradecenol (Z9-14:OH) and Z9-tetradecenal (Z9-14:Ald) when compared to female antennae. While we could show electrophysiological responses to single pheromone compounds, behavioral attraction of males was dependent on the synergistic effect of at least two of these compounds. Signal specificity is shown to be gained through pheromone blends. A field trial showed that a significant number of males were caught only in traps baited with a combination of Z9-14:OAc (circa 95% of the ratio) and Z9-14:OH. Addition of 14:OAc to this mixture also improved the number of males caught, although not significantly. This study represents a major step towards developing a useful attractant to be used in management tools for C. tristis and contributes to the understanding of chemical communication and biology of this group of insects.     

Molecular Discrimination of Garfish Hyporhamphus (Beloniformes) Larvae in Southern Australian Waters

A multiplex polymerase chain reaction (PCR) assay developed for discrimination between garfish larvae (family Hemiramphidae, order Beloniformes) found in southern Australian waters was based on species-specific amplification of part of the mitochondrial control region. The species were easily discerned by the number and distinct sizes of PCR products (Hyporhamphus melanochir, 443 bp; H. regularis, 462 and 264 bp). Although based on a single gene, the method will correctly identify the species of individuals in at least 96% of tests for H. melanochir and 94% of tests for H. regularis. Received January 17, 2001; accepted April 25, 2001.     

Prevalence of Salmonella in Australian reptiles

From January 2007 until June 2008, 504 reptiles of four families and 57 species were examined for Salmonella by using cloacal or intestinal swabs. Salmonella was identified in 139 (28%) of the 504 animals tested. Of the 504 reptiles examined, 210 were captive and 294 were wild. Ninety-eight (47%) of the captive reptiles were shedding Salmonella at the time of sampling. In contrast, only 41 (14%) of the wild reptiles were shedding Salmonella. The higher prevalence of Salmonella in captive reptiles was statistically significant (P<0.0001). No Salmonella was found in 60 wild, freshwater chelonians or 48 wild southern water skinks (Eulamprus heatwolei). Our results suggest that some species of wild reptiles in Australia are not natural carriers of Salmonella and that diet and captivity may influence Salmonella excretion in other species.     

A Comparative Study of Eubothrium Salvelini and E. crassum (Cestoda: Pseudophyllidea) Parasites of Arctic Charr and Brown Trout in Alpine Lakes

We compared the morphology, morphometry, and some aspects of the biology and ecology of Eubothrium crassum and E. salvelini, two pseudophyllidean tapeworms in brown trout, Salmo trutta m. lacustris, and Arctic charr, Salvelinus alpinus, in lakes of the western part of the Alps. The taxonomic importance of the apical disc for the discrimination of both taxa was confirmed. The apical disc of E. crassum is rectangular, possessing two deep grooves above the bothriae and 2–16 additional indentations. In E. salvelini, the apical disc is bilobed and bilaterally symmetric. We found new and significant interspecific differences in the length and width of the scolex, the diameter of the apical disc, and the width of the neck, with all measurements being larger in E. crassum. The two species differ in the number and size of the testes (fewer and larger in E. salvelini), the length of the cirrus sac (longer in E. crassum), and the size of vitelline follicles (larger in E. salvelini). Vitelline follicles of E. crassum are always cortical and sometimes enter into the outermost muscle fibres, whereas follicles of E. salvelini are situated largely medullary with few follicles entering between the innermost bundles of muscles. The eggs and the oncospheres of E. salvelini are larger. The embryonic hooks of E. crassum measure 14–18 m whilst those of E. salvelini are 18–26 m. For both taxa, the intraspecific variability in morphometric characters was fairly low. The prevalence and intensity of infection of E. crassum and E. salvelini in their respective fish hosts were very high (prevalence 90–94% mean intensity 36.3 and 6.6, maximums of 172 and 63 tapeworms per fish, respectively). E. salvelini eggs were spontaneously released throughout the year except for winter months; E. crassum laid eggs only in summer (June–August). Natural infection of copepods with Eubothrium procercoids was very low (prevalence 0.002%). The morphogenesis of Eubothrium procercoids was studied in an intermediate host, the copepod Cyclops prealpinus, that had been simultaneously infected with both species.     

Prevalence of Fleas and Gastrointestinal Parasites in Free-Roaming Cats in Central Mexico

The prevalence of fleas and gastrointestinal parasites in free-roaming and domestic cats in central Mexico was evaluated. Three hundred and fifty eight cats captured in the street or brought in by owners to the Animal Control Center Unit, a unit of State Government, from June 2010 to May 2011, were included in the study. All cats were examined for the presence of fleas and gastrointestinal worms. One-hundred and ninety (53%) cats were infested with at least one flea species. Single infestations were observed in 106 (30%) cats and mixed infestations in 84 (23%) cats. Four species of fleas were recovered: Ctenocephalides felis in 53% of the cats, C. canis in 18%, Echidnophaga gallinacea in 7% and Pulex irritans in 1%. One-hundred and sixty three (45%) cats were infected with one or more species of gastrointestinal parasites: 48 (13%) with nematodes, 145 (40%) with cestodes, and one animal presented Moniliformis moniliformis. Prevalences and mean intensity of infection were: Physaloptera praeputialis 7 and 18; T. cati 3 and 2; Ancylostoma tubaeforme 2.5 and 2; Toxascaris leonina 0.5 and 2; Dipylidium caninum 36 and 32; Taenia taeniformis 4 and 3 and Moniliformis moniliformis 0.3 and 106, respectively. There was significant association (P<0.01), between season and ectoparasites load, more fleas were obtained in the summer and autumn than in the winter and spring; however, no statistical difference was observed for endoparasites load (P>0.05). The correlation between the total number of ectoparasites and endoparasites was not significant (r = 0.089, P = 0.094).     

Recrystallization in a Freezing Tolerant Antarctic Nematode,Panagrolaimus davidi,and an Alpine Weta,Hemideina maori(Orthoptera; Stenopelmatidae)

The ability of haemolymph from the freezing tolerant weta,Hemideina maori,and supernatant from homogenates of the freezing tolerant nematodePanagrolaimus davidito inhibit the recrystallization of ice was examined using the “splat freezing” technique and annealing on a cryomicroscope stage. There was no recrystallization inhibition in weta haemolymph or in insect ringer controls. Recrystallization inhibition was present in the nematode supernatant but this was destroyed by heating and was absent in controls.P. davidisurvives intracellular freezing and recrystallization inhibition may be important for the survival of this stress.     

Molecular Cloning and Characterization of Two Genes Encoding Tryptophan Decarboxylase from Aegilops variabilis with Resistance to the Cereal Cyst Nematode (Heterodera avenae) and Root-Knot Nematode (Meloidogyne naasi)

Tryptophan decarboxylase (TDC), which catalyzes the conversion of Trp to tryptamine, provides a common backbone for many secondary metabolites, and is important in defending plants from abiotic stress such as pathogen infection and insect attack. In this study, we cloned two TDC genes, AeVTDC1 and AeVTDC2, from Ae. variabilis accession No. 1 with resistance to cereal cyst nematode (CCN) and root-knot nematode (RKN). AeVTDC1 and AeVTDC2 encode polypeptides of 510 and 518 amino acids, respectively, and both have a pyridoxal phosphate attachment site and specific catalytic residues. Comparative analyses of gene structure and amino acid motifs revealed that TDCs are highly conserved crossing the analyzed species in monocots and dicots. Phylogenetic analysis indicated that AeVTDCs were closer to TDCs of wheat, Ae. tauschii, Triticum urartu, Brachypodium distachyon, and Hordeum vulgare. Their functions and temporal and spatial expression patterns were investigated. Moreover, AeVTDC1 and AeVTDC2 exhibited different expression responses to the phytohormones abscisic acid, salicylic acid, and methyl jasmonate, suggesting that they may function differently in response to biotic and abiotic stresses. The inhibition of TDC activity with S-αFMT resulted in susceptibility of Ae. variabilis to CCN and RKN, suggesting that TDCs may play important roles in resistance to nematodes.

     

Prevalence and evolutionary relationships of haematozoan parasites in native versus introduced populations of common myna Acridotheres tristis

The success of introduced species is frequently explained by their escape from natural enemies in the introduced region. We tested the enemy release hypothesis with respect to two well studied blood parasite genera (Plasmodium and Haemoproteus) in native and six introduced populations of the common myna Acridotheres tristis. Not all comparisons of introduced populations to the native population were consistent with expectations of the enemy release hypothesis. Native populations show greater overall parasite prevalence than introduced populations, but the lower prevalence in introduced populations is driven by low prevalence in two populations on oceanic islands (Fiji and Hawaii). When these are excluded, prevalence does not differ significantly. We found a similar number of parasite lineages in native populations compared to all introduced populations. Although there is some evidence that common mynas may have carried parasite lineages from native to introduced locations, and also that introduced populations may have become infected with novel parasite lineages, it may be difficult to differentiate between parasites that are native and introduced, because malarial parasite lineages often do not show regional or host specificity.     

Molecular Phylogeny Analysis and Species Identification of Dendrobium (Orchidaceae) in China

Dendrobium plants are important commercial herbs in China, widely used in traditional medicine and ornamental horticulture. In this study, sequence-related amplified polymorphism (SRAP) markers were applied to molecular phylogeny analysis and species identification of 31 Chinese Dendrobium species. Fourteen SRAP primer pairs produced 727 loci, 97% of which (706) showed polymorphism. Average polymorphism information content of the SRAP pairs was 0.987 (0.982–0.991), showing that plenty of genetic diversity exists at the interspecies level of Chinese Dendrobium. The molecular phylogeny analysis (UPGMA) grouped the 31 Dendrobium species into six clusters. We obtained 18 species-specific markers, which can be used to identify 10 of the 31 species. Our results indicate the SRAP marker system is informative and would facilitate further application in germplasm appraisal, evolution, and genetic diversity studies in the genus Dendrobium.     

Parasites of moose (Alces alces) from an agricultural area of eastern Ontario

Viscera of 16 moose and hide samples of 24 moose (Alces alces) shot in eastern Ontario in 1985 were examined for parasites. Two species of trematodes, one species of cestode, five species of nematodes and one species of tick were recovered. One nematode species, Trichuris discolor, is reported for the first time from moose. Our results suggest that the parasite fauna of the moose may have been influenced by the absence or scarcity of other species of wild cervids or carnivores and by the presence of domestic livestock.     

Molecular phylogeny and systematics of Australian and East Timorese Stenothyridae (Caenogastropoda: Truncatelloidea)

The Australian and East Timorese species belonging to the truncatelloid family Stenothyridae are revised using molecular data and morphological characters from the shell, operculum, radula and external and reproductive anatomy. The Australian species Stenothyra australis is redescribed and two previously recognised subspecies are shown to be synonyms. The New Guinean species Stenothyra paludicola van Benthem Jutting, 1963 Benthem Jutting, W.S.S. van (1963) Non-marine Mollusca of West New Guinea. Part I: Mollusca from fresh and brackish waters. Nova Guinea, Zoology 20, 409–521. [Google Scholar] is redescribed and recorded from the Torres Strait region of northern Australia, and two new subspecies of S. paludicola are described from the Northern Territory and East Timor; S. paludicola topendensis n. subsp. and S. paludicola timorensis n. subsp. respectively. Stenothyra gelasinosa n. sp. is described from Australia, comprising three allopatric subspecies; S. gelasinosa gelasinosa n. sp. and n. subsp. from the eastern seaboard, S. gelasinosa phrixa n. subsp. from northern Australia and S. gelasinosa apiosa n. subsp. from the Pilbara region of Western Australia. Stenothyra frustillum is considered a nomen dubium. Molecular phylogenetic analysis of these taxa and other Asian stenothyrids supports these systematic decisions and provides a preliminary interpretation of relationships within Stenothyridae.