No abstract

Biodiversity research along altitudinal gradients can provide us with new insights into conservation and human impacts. In this context, amphibians are a useful and important group due to their rapid response to environmental changes, severely threatened status and because of the gaps in our knowledge of their ecology, especially in tropical forests. Here, we investigate the differences in amphibian communities along an altitudinal gradient with the aim to understand how different groups respond to altitude and what factors drive such responses. We carried out our research in the Piñi-Piñi range, located in the Manu Biosphere Reserve (south-eastern Peru), a global biodiversity hotspot. We evaluated the changes in abundance, alpha, beta and functional diversity of the community with altitude along transects from 450 to 1150 m asl. We categorized species into functional groups based on their breeding sites, habitat and weight. Alpha diversity for the overall community decreased with increasing altitude, a trend partially driven by the absence of aquatic habitats in the higher elevations, which prevents colonisation by pond and stream breeders. Community composition changed with altitude and there was a low similarity between lower and higher elevations. Upper elevations were less diverse but contained species found nowhere else along the gradient, increasing the diversity of the range. Functional groups responded to altitude in different ways and several groups were absent or almost absent from the upper elevations: large species (>10 g), terrestrial, arboreal, and pond and stream breeders. Pond and stream breeders and those species found exclusively in the higher areas of the range are likely more vulnerable to habitat and climate change. Investigating the response of different functional groups and using multiple measures of diversity was useful for generating a detailed understanding of the changes in the community with altitude and their ecological and conservation implications.

SUMMARYOne-worm infections ofHymenolepis diminutain rats had their strobila severed surgically, in the neck region, on day 14 of an infection. The scolex and remaining strobila survived but were recovered from a more posterior region of the intestine where small worms are attached during development. The movement to the new region was usually not complete in 24 h, but was complete by 72 h, and probably by 48 h. The operation, involving laparotomy and an incision in the duodenal wall which avoided severing the strobila, had no effect on the position of the worm but did depress the growth of the worm during the ensuing 24 h. It is suggested that (1) the preferred site forH. diminutais 30–50 % down the small intestine, (2) the worm monitors information about its position from all over its strobila and (3) as the worm grows, its position is determined by balancing the input of adverse information from its tail and head ends. The slowness with which surgically shortened worms return to the preferred site may be due either to delay in the worm ‘realising’ it has no tail, or to the location stimuli in the intestine being disturbed for 24 h by the operation.

Elachistocleis muiraquitan was recently described from fifteen specimens found at two sites in Acre state, northwestern Brazil. Prior to the description of E. muiraquitan, individuals fitting the description of this species found in southeastern Peru and northwestern Bolivia were identified as Elachistocleis bicolor, a species associated with markedly different habitat and environmental conditions. Here, we re-identified these specimens and also propose the first map of E. muiraquitan’s potential distribution, based on known localities along with climatic and environmental parameters.