Shade of Pelage Color in Two Populations of Kangaroo Rats and Remarks on the Status of Dipodomys merriami ambiguus Merriam

1949 ◽  
Vol 30 (4) ◽  
pp. 388 ◽  
Author(s):  
W. Frank Blair
Keyword(s):  
Kangaroo Rats ◽  
Dipodomys Merriami ◽  
The Status ◽  
Pelage Color ◽  
Two Populations

scholarly journals Expansion of the marbled crayfish in Slovakia: beginning of an invasion in the Danube catchment?

2016 ◽  
Author(s):  
Boris Lipták ◽  
Agata Mrugała ◽  
Ladislav Pekárik ◽  
Anton Mutkovič ◽  
Daniel Gruľa ◽  
...  
Keyword(s):  
Horizontal Transmission ◽  
Local Population ◽  
Danube River ◽  
Exotic Fish ◽  
The Danube River ◽  
Procambarus Fallax ◽  
Danube Catchment ◽  
The Status ◽  
Marbled Crayfish ◽  
Two Populations

The marbled crayfish, <em>Procambarus fallax</em> f. <em>virginalis</em>, is a taxon widely available in the aquarium pet trade, which has been introduced to open waters in several European countries and in Madagascar. Recent studies confirmed this parthenogenetically reproducing crayfish as a high-risk invasive species, and vector of the crayfish plague pathogen, <em>Aphanomyces</em> <em>astaci</em>. It has been first discovered in Slovakia in 2010, but the status of the local population was not studied since then. Due to enlarged sampling area around the first report and one locality, where we presupposed the crayfish occurrence, we identified new marbled crayfish populations. Here, we report presence of three newly established marbled crayfish populations in Slovakia. Two populations are located critically close to the Váh River, a major tributary of the Danube River; one of them being directly connected to the Váh River <em>via</em> a side channel during occasional floods. The third established marbled crayfish population was found at the mouth of a thermal stream flowing into the Nitra River, a tributary of the Váh River. In this stream, crayfish coexist with other exotic fish and gastropod species of aquarium origin. We presume that the reported localities may serve as a source for further expansion of the marbled crayfish in the mid-part of the Danube catchment. Floods, active dispersal (including overland), passive dispersal by zoochory or anthropogenic translocations are among the major drivers facilitating the marbled crayfish colonization. We have not detected the crayfish plague pathogen in any of the studied populations. However, if spreading further, the marbled crayfish will encounter established populations of crayfish plague carriers in the Danube River, in which case they may acquire the pathogen by horizontal transmission and contribute to spread of this disease to indigenous European crayfish species.

Prevalence of cutaneous evaporation in Merriam's kangaroo rat and its adaptive variation at the subspecific level

2000 ◽  
Vol 203 (4) ◽  
pp. 773-781 ◽  
Author(s):  
R.L. Tracy ◽  
G.E. Walsberg
Keyword(s):  
Water Loss ◽  
Evaporative Water Loss ◽  
Evaporative Water ◽  
Kangaroo Rats ◽  
Dipodomys Merriami ◽  
Kangaroo Rat ◽  
Mesic Site ◽  
Merriam's Kangaroo Rat ◽  
Cutaneous Evaporation ◽  
Subspecific Level

Previous estimates suggested that ventilatory evaporation constitutes the major source of water loss in kangaroo rats (Dipodomys spp.). We quantified rates of water loss in Merriam's kangaroo rat (Dipodomys merriami) and demonstrate the degree to which acclimation to a particular thermal and hydric environment plays a role in the intraspecific variation in water loss evident in this species. We draw the following conclusions: (1) that water loss varies intraspecifically in Merriam's kangaroo rat, in association with habitats of contrasting aridity and temperature; (2) that animals from more xeric locations have lower water loss rates than those from more mesic sites; (3) that most water loss is cutaneous, with ventilatory evaporative water loss contributing, at most, only 44% to total evaporative water loss; and (4) that intraspecific differences in rates of water loss are not acclimatory, but fixed. After acclimating under the same conditions, xeric-site animals still show a 33% lower rate of evaporative water loss than mesic-site animals.

Wheel running of kangaroo rats, Dipodomys merriami, as related to food deprivation and body composition

1978 ◽  
Vol 44 (1) ◽  
pp. 17-20 ◽  
Author(s):  
D. B. Dill ◽  
L. F. Soholt ◽  
J. D. Morris
Keyword(s):  
Weight Loss ◽  
Body Composition ◽  
Body Weight ◽  
Food Deprivation ◽  
Body Fat ◽  
Wheel Running ◽  
Initial Amount ◽  
Kangaroo Rats ◽  
Dipodomys Merriami ◽  
Percentage Of Body Fat

Kangaroo rats deprived of food ran themselves to death in 48 h in wheel cages. Despite the loss of 14.5% of body weight the ratio of water to protein was the same after the run as it was in control rats. Metabolic measurements at rest and in the running wheel and weight loss in the 48-h run were used to estimate fuels used and water expended. Two-thirds of the initial amount of fat and 9% of the protein were metabolized. The terminal mean percentage of body fat was about twice that observed in rats trapped in the spring of 1967, when seed production was low: death in the 48-h run could not have been due to depletion of body fat alone. The powerful activity drive seen in hungary kangaroo rats presumably is intensified in dry years when food is scarce and may deplete their reserves enough to result in death from starvation.

Scatter hoarding by kangaroo rats (Dipodomys merriami) and pilferage from their caches

1992 ◽  
Vol 3 (2) ◽  
pp. 102-111 ◽  
Author(s):  
Martin Daly ◽  
Lucia F. Jacobs ◽  
Margo I. Wilson ◽  
Philip R. Behrends
Keyword(s):  
Scatter Hoarding ◽  
Kangaroo Rats ◽  
Dipodomys Merriami

Genetic-Evidence for Sympatric Differentiation Between 2 Color Morphs of the Skink Egernia-Whitii

1990 ◽  
Vol 38 (2) ◽  
pp. 117 ◽  
Author(s):  
DA Milton
Keyword(s):  
Low Frequency ◽  
Mate Recognition ◽  
Colour Pattern ◽  
Linkage Disequilibria ◽  
Color Morphs ◽  
The Status ◽  
Colour Patterns ◽  
Colour Morphs ◽  
Granite Rocks ◽  
Two Populations

The viviparous skink Egernia whitii is dimorphic for dorsal colour pattern. Both patterned and plain morphs coexist throughout the species' range. Adults live in family groups beneath exfoliating granite rocks. The closely related E. modesta also coexists in similar habitats in the northern part of the range of E. whitii. The plain E. whitii morph is intermediate in colour pattern between patterned E. whitii and E. modesta. Three populations of E. whitii and two populations of E. modesta were examined electrophoretically to assess the status of the plain morph of E. whitii. There were no fixed differences between the two morphs of E. whitii at any of the 55 loci examined, and loci polymorphic in both rnorphs of E. whitii showed no evidence of linkage disequilibria. Although heterozygosity values (H=0.017�0.002) and the level of polymorphism (P 0.95=0.015) were low, there were highly significant allele frequency differences between sympatric samples of the two morphs of E. whitii. This indicated that the two morphs were conspecific, yet they were not interbreeding at random. The established frequency of gene exchange between the two colour morphs in the three populations sampled varied from 3.6 to 6 individuals per generation. Reproductive data confirmed that both colour morphs of E. whitii produced young of the same dorsal colour pattern as their own in much greater frequency than random. However, females of both colours can and do breed with males of the other colour in very low frequency. Analysis of the lateral colour pattern of the two E. whitii morphs and E. modesta suggests that the colour patterns of the two E. whitii morphs are very similar, yet differ slightly from the colour pattern of E. modesta in the region of geographic overlap of these species. These results suggest that behavioural or microhabit differences between the two morphs may be involved in mate recognition.

Aboveground Activity of Merriam's Kangaroo Rats (Dipodomys Merriami) in Relation To Sex and Reproduction

Behaviour ◽  
1986 ◽  
Vol 96 (3-4) ◽  
pp. 210-226 ◽  
Author(s):  
Philip Behrends ◽  
Margo I. Wilson ◽  
Martin Daly
Keyword(s):  
Kangaroo Rats ◽  
Dipodomys Merriami ◽  
Merriam's Kangaroo Rats
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