Thermal refugia and persistence of Texas horned lizards (Phrynosoma cornutum) in small towns.

Vegetation loss is a primary cause of habitat degradation and results in a decline in reptile species abundance due to loss of refuge from predators and hot temperatures, and foraging opportunities. Texas horned lizards (Phrynosoma cornutum) have disappeared from many areas in Texas, especially from urbanized areas, probably in large part due to loss of suitable habitat. This species still occurs in some small towns in Texas that still contain suitable habitat. Long-term data from Kenedy and Karnes City, Texas indicate that when study sites experienced significant shrub and vegetation removal horned lizards declined by 79%. We hypothesize the decline was due to the degradation of the thermal landscape for these lizards. We determined the preferred temperature range (T set25 - T set75) of lizards at our study sites and took field measurements of body temperature (T b). Temperature loggers were also placed in three microhabitats across our study sites. Shrubs and vegetation provided the highest quality thermal environment, especially for about 5 h midday when temperatures in the open and buried under the surface in the open exceeded the lizards' critical maximum temperature (CTmax) or were above their preferred temperature range. Horned lizard density was positively related to the thermal quality of the habitat across our sites. Texas horned lizards in these towns require a heterogeneous mix of closely spaced microhabitats and especially thermal refugia, such as shrubs and vegetation along fence lines and in open fields. Maintaining thermal refugia is one of the most important and practical conservation actions that can be taken to help small ectotherms persist in modified human landscapes and cope with increasing temperatures due to climate change.

Mislabelling and high mercury content hampers the efforts of market-based seafood initiatives in Peru.

Peru is experiencing a "gastronomic boom" that is increasing the demand for seafood. We investigated two implicit assumptions of two popular sustainable seafood consumer-based initiatives: (1) seafood is labelled correctly, and (2) the recommended species are healthy for consumers. We used DNA barcoding to determine the taxonomic identity of 449 seafood samples from markets and restaurants and analysed the concentration of total mercury (THg) in a sub-sample (271 samples) of these. We found that a third of seafood is mislabelled and that over a quarter of all samples had mercury levels above the upper limit recommended by the US EPA (300 ng/g ww). Additionally, 30% of samples were threatened and protected species. Mislabelling often occurred for economic reasons and the lack of unique common names. Mislabelled samples also had significantly higher mercury concentrations than correctly labelled samples. The "best choice" species compiled from two sustainable seafood guides had less mislabelling, and when identified correctly through DNA barcoding, had on average lower mercury than the other species. Nevertheless, some high mercury species are included in these lists. Mislabelling makes the efforts of seafood campaigns less effective as does the inclusion of threatened species and species high in mercury.

Microhabitat and niche separation in species of Ceratiomyxa.

The eumycetozoan genus Ceratiomyxa appears to have a cosmopolitan distribution, although two of the three macroscopic species within the genus have been reported only from tropical regions of the world. In theory these two tropical species might be expected to display more narrow niches than their cosmopolitan counterpart due to their specialization for tropical environments. However ecological data documenting niche separation in eumycetozoans are largely lacking. As part of several investigations carried out in the neotropics the ecology of the three macroscopic species of Ceratiomyxa was studied. The results from in situ measurements of environmental factors associated with their fructifications reveal a clear separation of niches between the two tropical species, which might be an indication of resource partitioning within the genus. As expected in theory the cosmopolitan C. fruticulosa shows the broadest niche of the three species. Moreover the niche overlap value between C. morchella and C. sphaerosperma along with results from a multivariate CDA analysis seem to indicate that these two species are more specialized than C. fruticulosa.