Molecular identification and morphological variations of Dermacentor albipictus collected from two deer species in northern Mexico

Experimental and Applied Acarology - In total, 57 ticks were collected from six white-tailed deer (Odocoileus virginianus) and three mule deer (O. hemionus) in northern Mexico during the 2017, 2018...     

Sex identification of morphologically-undifferentiated Siberian sturgeon with statistical analysis of gene expression patterns

The purpose of this study was to detail a simple strategy for sexing morphologically-undifferentiated fish using statistical analysis of gene expression patterns characterized by quantitative PCR. This approach is especially relevant for species without known genomic sex markers. The method was developed for early identification of female Siberian sturgeon as part of a genomics study. That study documented activation of the enzyme 17ß-hydroxy-steroid-dehydrogenase (hsd17b1) in future ovarian tissue at 3 months of age, concurrent with a small forkhead box L2 (foxl2) peak and emerging cytochrome P450, family 19, subfamily A (cyp19a1) expression. Major cyp19a1 and foxl2 peaks occurred in presumptive female gonads at 5–6 months. This pattern suggested a genetic relay mediating estrogen production throughout differentiation, possibly to maintain gonadal femininity. Genes involved in stem cell proliferation (lim homeobox 2 (lhx2)) and somatic-germ cell interaction maintenance (iroquois homeobox 5 (irx5) and iroquois homeobox 3 (irx3)) were also expressed during molecular differentiation, at 5–6 months. The roles of lhx2, irx3, and irx5 in fish sex differentiation should be confirmed using other methodologies. These results indicate that estrogens are crucial for ovarian differentiation in basal non-teleost fish, consistent with well-established patterns in teleosts, with hsd17b1 as one of the earliest biomarkers of gonadal development.     

Environmental gradients drive physiological variation in Hawaiian corals

Coral Reefs - To evaluate potential coral adaptive mechanisms, we investigated physiological traits (biomass, lipid, protein, chlorophyll, and isotopic proxies for trophic strategy) in eight...     

Population-level impacts of natural and anthropogenic causes-of-death for Hawaiian monk seals in the main Hawaiian Islands

Identifying, assessing, and ranking the impact of individual threats is fundamental to the conservation and recovery of rare and endangered species. In this analysis, we quantify not only the frequency of specific causes-of-death (CODs) among Main Hawaiian Island (MHI) monk seals, but also assess the impact of individual CODs on the intrinsic growth rate, λ, of the MHI population. We used gross necropsy results, histopathology, and other evidence to assign probabilities of 11 COD types to each mortality and then used Monte Carlo sampling to evaluate the influence of each COD on λ. By right censoring realizations involving specific CODs, we were able to estimate λ (and its associated uncertainty) when CODs were selectively removed from influencing survival. Applying the analysis to all known and inferred deaths believed to have occurred 2004–2019, the CODs with the largest influence on λ were anthropogenic trauma, anthropogenic drowning, and protozoal disease. In aggregate, anthropogenic CODs had a larger effect on the growth rate than either natural or disease CODs. Possible bias associated with differential carcass detection, recovery, and COD classification are discussed.     

Higher structural connectivity and resistance against invasions of soil bioengineering over hard-engineering for riverbank stabilisation

Wetlands Ecology and Management - Riparian corridors play an important role for the maintenance of regional biodiversity and ecosystem functions. Riparian forests are even the only semi-natural...     

Effect of non-native species on taxonomic and functional diversity of fish communities in different river types

Recent researches suggest that functional diversity represents the response of communities to environmental alterations better than taxonomic diversity. However, there is scarce information about how the functional diversity of freshwater fishes is affected by habitat type and the dominance of non-native species. To address this question, we analysed a large database containing 15 morpho-functional traits of 61 fish species from the Pannon Biogeographic region (Hungary). Based on a fish faunistic list and relative abundance of taxa, we quantified the taxonomic and functional diversity of riverine communities for?>?700 sites of six habitat types. We asked how non-native fishes affected the taxonomic and functional diversity in different river types and at the local scale (i.e. at the site level), and how the diversity measures of native fauna elements changes along the invasion gradient. Our results showed that both functional and taxonomic richness increases with habitat complexity, from small headwater streams to large rivers. Therefore taxonomic diversity served as a good proxy for functional diversity along the environmental gradient of river types. Non-natives showed considerable functional diversity relative to their species number in each habitat type. Diversity values of native fauna elements initially increased, and then showed a major decrease along the invasion gradient. River type-specific evaluations highlighted the importance of considering the proliferation of invasive species based on both taxonomic and functional diversity indices. We argue that type-specific action plans are needed in conservation management to preserve the taxonomic and functional diversity of native fishes in Hungary, but also elsewhere.

     

Sphingobacterium pedocola sp. nov. a novel halotolerant bacterium isolated from agricultural soil

Antonie van Leeuwenhoek - A Gram-reaction-negative halotolerant bacterial strain, designated Ka21T, was isolated from agricultural soil and characterised using a polyphasic approach to determine...