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1.
《Journal of Natural History》2012,46(19-20):1421-1434
We studied a population of Crossodactylus bokermanni in a stream at the Reserva Particular do Patrimônio Natural, Santuário do Caraça, south‐eastern Brazil, with respect to microhabitat use and diet. We characterized microhabitats based on substrate, distance to water and exposure level of the occupying individual (exposed or sheltered), and adjacent aquatic microhabitats (evaluated as potential nesting sites based on observed nests), according to water current (absent, slow or fast), substrate and depth. Calling males, silent males, ovigerous females, non‐ovigerous females and juveniles showed spatial niche overlap higher than that expected by chance, with calling males showing the strongest preference for microhabitats close to potential nesting sites (with intermediate depths, fast current and sandy bottom). Only 14 males out of 48 individuals examined for stomach contents had prey in their stomachs. The food items with the highest electivity values were Coleoptera and Diptera, but preys with both high and low mobility were exploited.  相似文献   

2.
Climate change and fire suppression have facilitated expansion of pinyon-juniper woodlands into sagebrush-steppe ecosystems of the Great Basin, USA, resulting in a loss of biological diversity. To assess the effects of using prescribed fire in restoration efforts, ant abundance, species richness, and composition were examined pre- and post-burn along the elevation and tree cover gradients encompassed by a pinyon-juniper woodland in a central Nevada watershed. Ants were sampled using pitfall traps in 6 sites for the elevation study and in 2 sites for the tree cover study, representing paired burn and control sites in a randomized block design. Vegetation and ground cover variables were also sampled to determine how variation in ant populations was correlated with differences in vegetation and ground cover. Ant species richness remained unchanged for all treatments. Tree cover had no significant effect on ant populations. Significantly more ants were trapped after the burn treatment on burn plots. Variation in ant populations was not directly correlated with any of the vegetation or ground cover variables. According to ANOVA and multivariate analyses, elevation had the greatest effect on changes in ant communities, likely due to increased moisture availability. Our results suggest that management for conservation of sagebrush-steppe ecosystems in this and similar watersheds should include a range of elevations to ensure maximum ant species diversity.  相似文献   

3.
《Journal of Natural History》2012,46(43-44):2661-2668
In the laboratory, wild-caught male Rhinoderma darwinii frogs, but not females, changed body colour from brown to green starting with the appearance of green dorsal spots or a greenish dorsal tone on a brown body colour. After a year in captivity, most males exhibited a greenish or complete green dorsal colour, probably induced by the terrarium's swamp (green) vegetation and season.  相似文献   

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《Journal of Natural History》2012,46(19):1653-1673
This study details the morphology of Platyallabes tihoni (Poll, ) as part of a complete revision of the anguilliform clariids. The overall body form of air‐breathing clariids ranges from fusiform to anguilliform genera (Boulenger ; Pellegrin ). Although P. tihoni has the typical external morphological features of other elongate clariids, this study shows that it occupies an intermediate position between fusiform and anguilliform taxa with regards to its cranial and postcranial morphology. The main morphological similarities of anguilliform species are a narrow skull roof with a high level of interdigitation between the bones, the reduced canal bones, a connection between the neurocranium and suspensorium via several processes, an extended tooth patch on the lower jaw, and the hypertrophied jaw muscle complex. Shared features typical for the fusiform species are a low coronoid process on the lower jaw and the posteroventral orientation of the opercular process on the hyomandibula. Platyallabes tihoni shows a series of unique features: an anterior fontanel situated entirely between the frontals, two tooth plates on the prevomer, a reduced height of the suspensorium, the absence of an anterior bony plate on the hyomandibula, a horizontal position of the sphenotic and pterotic, and a toothed entopterygoid. Many of these unique characters are linked to the spatial constraints associated with an extremely flattened skull in this species.  相似文献   

6.
Since the pioneering works of the Norwegian biologist G.O. Sars, little attention has been given to the freshwater harpacticoids in Norway. The prime purpose of this paper is to present the state of current knowledge about the Norwegian freshwater harpacticoid fauna based on all known published and unpublished literature and archive material. We highlight the contribution of G.O. Sars to the knowledge of this group by presenting his remaining unpublished archive material. We present two Norwegian species checklists – one for freshwater harpacticoids (16 species) and another for freshwater-associated/brackish-water harpacticoids (nine species). Four of the freshwater harpacticoid species are described by G.O. Sars. Original unpublished plates with drawings of those species are included in the paper. In addition, an overview of species distributions throughout the country is given.  相似文献   

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《Journal of Natural History》2012,46(20):2567-2589
Three species of darwinulid ostracods, belonging to the genus Penthesilenula, are reported from terrestrial and semi-terrestrial habitats in São Paulo State (Brazil). Penthesilenula reidae n. sp. is here described as new to science. It belongs to the africana-group in the genus and was found exclusively in bromeliad pouches. Penthesilenula aotearoa (in the incae-group) was previously known from New Zealand only and is here reported for the first time from South America. The third species, Penthesilenula brasiliensis, is here described from leaf litter in forests, constituting the first darwinulid taxon to be found in fully terrestrial habitats. The morphological diversity within P. brasiliensis s. l. is discussed and various lineages on different continents are retained within this species. The evolutionary significance of the high incidence of teratologies in the Darwinulidae is discussed. A tentative homology for the apical chaetotaxy of A2 between Darwinulidae and Cyprididae is offered.  相似文献   

9.
《Journal of Natural History》2012,46(35-36):2327-2362
This paper critically compares the Southern African bulldog fish species Marcusenius macrolepidotus (Peters, 1852), inhabiting the eastern Lower Zambezi River, and Marcusenius altisambesi Kramer et al., 2007, inhabiting the central Upper Zambezi River, with bulldog fish samples from the western lower Cunene River, a 2600-km range from the Indian Ocean to the Atlantic. The three species or forms are well differentiated in morphology and molecular genetics, and differentiation is also present in electric organ discharges. Marcusenius altisambesi and the Cunene sample, which we recognize as Marcusenius multisquamatus sp. nov., are closely related and form a sister taxon to M. macrolepidotus. This result is based on the analysis of mitochondrial cytochrome b sequences and genomic Inter-simple-sequence-repeat fingerprinting. Morphological adaptations to life in a torrential escarpment river seem to be present in M. multisquamatus sp. nov. when compared with M. altisambesi, which lives in a reservoir river that periodically floods the savannah. http://www.zoobank.org/urn:lsid:zoobank.org:pub:8FE68494-9ED9-428E-B181-E814D25493F2  相似文献   

10.
《Journal of Natural History》2012,46(7-8):447-468
Three hundred and three individuals representing 14 species of lizards (Scincidae), collected in Papua New Guinea, were examined for metazoan endoparasites. Two species of Digenea, four species of Cestoda, 21 species of Nematoda (adults and larvae in cysts), two species of Acanthocephala and one species of Pentastomida were found. Forty-two new host records and two new locality records are reported. Skinks from Papua New Guinea are infected by “generalist” endoparasites, which parasitize a variety of reptile or amphibian hosts. Mean endoparasite species diversity per skink species was 5.0 ± 3.3 SD, range: 1–11.  相似文献   

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Summary

A population of Chaetogaster limnaei limnaei Gruffydd, living on various molluscs in the Worcester-Birmingham canal, was studied from February 1971 to February 1973 in the course of a detailed study of the digeneans parasitizing the molluscs.

The incidence of C. l. limnaei on each of its hosts was recorded for each month during the sampling period.

The incidence of the worms was high during the winter months on Physa fontinalis (and Lymnaea peregra) but low during the summer, and was high during the summer and low during the winter on Bithynia tentaculata.

It is postulated that this pattern of incidence may have been due to a migration of the worms from the pulmonate hosts to B. tentaculata in late spring, when the large pulmonates died after breeding, and a return migration to the pulmonates the following autumn.

There was found to be no association between the digeneans parasitizing the molluscs and the occurrence of the oligochaetes, and it is suggested that in this case the oligochaetes have no influence on the parasitic burden of the molluscs.  相似文献   

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