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Within the zoological disciplines the study of mammalian hair has mostly been limited to cross-species comparisons, but there is also considerable intraspecific variation in hair characteristics that may be biologically meaningful and deserving of study, though it can be tedious to manually measure hundreds of hairs under a microscope. Here a method is presented for assessing a variety of morphological characteristics of mammalian hairs that is fast, nearly fully-automated, does not require a microscope, and that could easily be used by wildlife biologists or researchers studying museum skins. Using hair samples from 6 captive white-tailed deer (Odocoileus virginianus) hairs were placed in groups of ten on white 3 × 5 inch index cards and covered with clear packing tape. Cards were scanned with a standard flatbed scanner at high resolution (1200dpi) and the images imported into a computer image analysis program. The program automatically selected and measured each hair, relayed the data to a text file, and cycled through all images so that the 120 deer hairs examined (20 per animal) were all measured within 5 minutes. The data returned included the length of each hair (even if it was curly), the width (the average width of the entire shaft), the 2-dimensional surface area, as well as the colour of the hair, measured with hue and brightness scores averaged over the entire shaft. These data are well-suited for examining questions regarding factors influencing the morphology or colour of mammalian pelage, or for using hair morphology to assess the nutritional status of individuals, as is done with humans. When measurements are completed, cards can be conveniently stored, either in an index card box or ringed binder, and they can even be re-scanned (at higher resolutions, for example) if needed. Alternatively, the index card step could be skipped and hairs could be scanned loosely in batches. Either way, this method should allow zoological researchers to pursue a wide variety of questions relating to mammalian hair morphology.
Black-backed jackals (Canis mesomelas, Schreber, 1775) survive in a wide range of environments. Their foraging strategies are highly variable in different habitats. Adaptations in foraging behaviour in relation to abundance and quality of food sources are expected to be highly pronounced in an extreme habitat like a desert. This study investigated the diet composition in black-backed jackals in the Namib Desert by analysing faecal samples collected between February 2004 and August 2005. Frequency of occurrence, relative dry mass and proportion of biomass consumed were calculated for different prey items. Insect parts, mainly of two species — the giant longhorn beetle (Acanthophorus capensis) and a locust (Anacridium moestum) — were found in 72.2% of the samples and were estimated to have contributed 22% to the biomass consumed. Mammals, predominantly rodents and ungulates, represented the highest proportion of biomass consumed (42%), although their remains were found in only one third of the samples. Based on biomass, mammals are assumed to be the jackal's preferred prey, but, probably due to lower abundance, more difficult to obtain than insects. More than 50% of the samples contained plant material, mainly seeds of !NARA plants (Acanthosycios horridus) and false ebony (Euclea pseudebenus), especially during their fruiting seasons. Although the abundance of A. capensis and of A. moestum varied annually, their remains were found in scats throughout the year, indicating a certain degree of specialization on these prey species.
Large hibernating aggregations and behaviour called late summer or autumn “invasions” when large groups of bats enter buildings are known in pipistrelles. We investigated differences in roosting behaviour between two cryptic species (common pipistrelle, Pipistrellus pipistrellus, and soprano pipistrelle, Pipistrellus pygmaeus) during autumn and winter periods. In total 463 bats were sampled in both caves and buildings with temporary occurrence during the period of late summer and autumn mating and presumable migrations from late July to September (10 sites), and in all known types of hibernacula from late November to March (34 sites). Sampling sites were located within the Czech Republic, Slovakia, Serbia and Romania in areas where the two species occur sympatrically throughout the summer. Using a DNA-based identification method, all but four individuals were identified as P. pipistrellus. It means that winter roosts of P. pygmaeus remain largely unknown in the area. Similarly, no P. pygmaeus was found in the “invasion” assemblages. Very abundant groups of P. pipistrellus in underground hibernacula and its exclusive occurrence in sites of “invasions” suggest that roosting behaviour during this time may be species-specific.
The objective of this work was to determine the concentrations of four heavy metals (Pb, Zn, Fe and Cu) in muscle and liver from the solitary subterranean rodent Ctenomys talarum from natural dunes, cultivated area and military area with the purpose of assessing their levels and their possible effect on the biology of this small mammal. Only Pb in tissues of C. talarum from the agricultural zone indicates a risk of toxic effects on the organism. Overall concentrations of heavy metals in soils and tissues of C. talarum from all areas are consistent with lightly polluted habitats, although the increments observed in areas under anthropic use suggest for the possibility that carrying out these human activities for long periods of time, or in an intensive way, could exert an evident impact on ecosystems.
We describe a new species of Scincella similar to Sphenomorphus tridigitus based on a single specimen from Lang Son Province, northeastern Vietnam. The new species differs from the latter by presence of lower eyelids with undivided opaque window, forelimbs with five digits, and by absence of prefrontals. Scincella apraefrontalis sp. n. is distinguished from all other species of Scincella and all other Asian limbreduced lygosomines by a combination of the following characters: no supranasals; no prefrontals; nasal and first supralabial fused; six supralabials; lower eyelid with undivided opaque disc; no external ear openings; 18 midbody scale rows; and pentadactyl limbs.
We studied the association between environmental variables and the terrestrial habitat use by adults of the burrowing toad Rhinella fernandezae in Buenos Aires, Argentina. We assessed the cover type, height of vegetation, soil moisture and hardness. We compared these habitat variables in quadrats where toads were present along a transect (n = 30 quadrats, 19 with toad burrows) with respect to randomly chosen quadrats (n = 17). We found that R. fernandezae does not use the habitat at random, and that habitat variables that mostly influenced its habitat use were soil hardness after raining, probably because it facilitates the construction of burrows, and broad-leaved plant cover, which may be affecting toads indirectly through other habitat variables, such as shadowing, air moisture and refuge from predators.
The morphometric, meristic and phenotypical characters of the members of the genus Alburnus from the Adriatic Basin were analyzed on specimens from 11 localities, representing eight watersheds. The number of gill rakers, the number of lateral line scales, the number of branched anal fin rays and the coverage of the ventral keel by scales have the greatest significance in differentiating between species. Significant morphological differences exist between the Alburnus population from Lake Lugano (type locality for Alborella maxima Fatio, 1882) and all the remaining investigated populations. Alburnus from the Neretva River drainage is described as a new species and it is distinguished from other species of the genus Alburnus by the following combination of characters: 13½-15½ branched anal fin rays; 17–26 gill rakers; 40–48 lateral line scales; first anal fin ray below branched dorsal rays 6–10 or located up to one scale after the last dorsal fin ray; ventral keel exposed for at least ⅔ of a distance between the pelvic fin base and the anal aperture. The status of the Neretva River basin populations as a separate species was corroborated by genetic analyses, with p-distance between newly described species and A. arborella from the Zrmanja River 1.8–2.2%.
The growth and reproductive biology of the invasive goldfish Carassius auratus auratus were studied in Lake Trasimeno, central Italy. The results of the research revealed that the population is made up of eight age-classes. The sex ratio proved to be extremely unbalanced (1 : 19 in favour of females). Growth can be deemed rapid, the von Bertalanffy growth in length function being TL = 43.019{1-e(-0.272(t 0.162) )} for the total sample and φ' = 2.702. No sexual dimorphism in growth was observed. Back-calculation analysis suggested the existence of an inverse Lee phenomenon among 1 year-old specimens. The reproductive period covers a broad time-span, from March to June. In females, sexual maturity is reached after the second winter of life (2 age-class); however, a small percentage (7.55%) of females is able to reproduce at the age of 1 year. Most of the males attained sexual maturity in the first year (60.61%). The reproductive investment of the females is high; the relationship between SL and the number of eggs was Ne = 0.0041 SL4.368. Fecundity varied from 286 to 219104 eggs, with an average relative fecundity of 103 ± 5 eggs g-1; the mean diameter of the eggs was 1.27 ± 0.01 mm. The reproductive investment of the females was not homogeneous across the ageclasses; in addition to absolute fecundity, relative fecundity and egg diameter were seen to increase with the size of the specimens.
The evaluation of resident fish communities is an important component of the ecological status assessment in aquatic habitats. Despite significant water quality improvement in the Czech Republic in the last decade, several important pollution sources in the Elbe River basin remain. The aim of the study was to evaluate fish community in a chronically polluted part of the channelized lowland Elbe River and its potential indicative capability.
The effluent from both industrial and municipal sewage treatment plant exhibited low pH, high conductivity and wide set of organic compounds (PAH, PCB, DDT etc.). Ecological characteristics of fish communities were obtained by boat electro fishing at selected sites in four inter-weir sections in July 2005 and 2006. Relatively high fish species richness (24 species) was observed in both seasons. Generalists (bleak, roach, chub) form the majority of the fish community in all four sections. There was no significant difference in fish species richness or density among study sections (river segments between weirs) even with a high level of measured organic compounds at the pollution inlet. Significant differences in fish species richness and density were registered among individual sites within study sections. Sites downstream the weirs had significantly higher species richness and density than the other two sites in the middle and upstream weirs. Fish community does not display any indicative remarks concerning water pollution, or in the case of mid-size river, sampling strategy was not efficient to recognize it. Channelization and regulation of the study stretch of the Elbe River seems to be the most important determinant of fish community structure.
The karyotype and major ribosomal sites as revealed by silver staining and CMA3-fluorescence of Croatian leuciscine cyprinid endemic to Cetina River, Telestes ukliva were studied. The diploid chromosome number was invariably 2n = 50. Karyotype consisted of eight pairs of metacentric, 13 pairs of submetacentric and four pairs subtelocentric chromosomes. The largest chromosome pair of the complement was subtelocentric, which is a characteristic cytotaxonomic marker for all representatives of the cyprinid lineage Leuciscinae. The nucleolar organizer regions (NORs) were detected in the telomeres of two pairs of mediumsized submetacentric chromosomes. Staining with CMA3 revealed four positive signals that corresponded to NOR sites. No heteromorphic sex chromosomes were found. The karyotype pattern of T. ukliva is nearly identical to that found in most other representatives of the Eurasian leuciscine cyprinids, while the multiple NOR phenotype appears to be more derived as opposed to a uniform one NOR-bearing chromosome pair, ubiquitous in this group.
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