84,123 research outputs found
Amphibian Contributions to Ecosystem Services
Ecosystems provide essential services for human society, which include provisioning, regulating, cultural, and supporting services. Amphibians provide provisioning services by serving as a food source for some human societies, especially in Southeast Asia. They also serve as models in medical research and provide potential for new pharmaceuticals such as analgesics and anti-viral drugs derived from skin secretions. Amphibians contribute to regulating services by reducing mosquito recruitment from ephemeral wetlands, potentially controlling other pest species, and indirectly through predation of insect pollinators. Often neglected, ecosystems also provide cultural services to human societies that increase the quality of human life through recreation, religion, spirituality, and aesthetics. As an abundant and diverse class of vertebrates, amphibians also play prominent roles in the culture of human societies through pathways such as mythology, literature, and art. Most research on the role of amphibians in ecosystems has been on their contribution to supporting services. This is also the area where amphibians are likely to have the largest contribution to ecosystem services. Supporting services have structural (e.g., habitat) and functional (e.g., ecosystem functions and processes) components. Amphibians can affect ecosystem structure through soil burrowing and aquatic bioturbation and ecosystem functions such as decomposition and nutrient cycling through waste excretion and indirectly through predatory changes in the food web. They also can control primary production in aquatic ecosystems through direct consumption and nutrient cycling. Unfortunately, amphibians are experiencing major declines and humans may be losing associated ecosystem services. It is important to understand how declines affect ecosystem services for human societies, but these declines can also serve as natural experiments to understand the role of amphibians in ecosystems
AMPHIBIAN AND REPTILE COLONIZATION OF RECLAIMED COAL SPOIL GRASSLANDS
While habitat loss is a major driver of amphibian and reptile declines globally, a subset of post-industrial landscapes, reclaimed and restored, are creating habitat for these animals. In a previous work, we showed that amphibians and reptiles use reclaimed and restored grasslands. In the present work we quantify captures at drift-fence/pitfall trap arrays over two consecutive years and show that several species of amphibians are not only successfully reproducing but that juveniles are being recruited into the population. In particular, 15,844 amphibians and 334 reptiles representing 25 species (14 amphibians, 11 reptiles) were captured at drift fences in 2009 and 2010. Nine additional reptile species were found opportunistically while conducting other research activities at the study site. Out of a total of 8,064 metamorphosing juveniles we detected 126 malformations, a 1.6% rate. The major malformation types were limbs missing (amelia) or foreshortened (ectromely), eye discolorations, and digits foreshortened (ectrodactyly) or small (brachydactyly). Our data show that reclaimed, restored, and properly managed landscapes can support reproducing populations of amphibians and reptiles with low malformation rates, including species in decline across other portions of their range
Loathsome Beasts: Images of Reptiles and Amphibians in Art and Science
The mythology and symbolism historically associated with reptiles and amphibians is unequaled by that of any other taxonomic group of animals. Even today, these creatures serve as icons - often indicating magic or evil - in a variety of media. Reptiles and amphibians also differ from other vertebrates (i.e. fish, mammals and birds) in that most have never been valued in Europe as food or for sport. Aside from some limited medicinal uses and the medical concerns related to venomous species, there was little utilitarian value in studying the natural history of reptiles and amphibians. Because of this history and other characteristics of these animals, the images of reptiles and amphibians played a unique role in the study of natural history from the Medieval through the Early Modern periods. The images I will discuss come from books that have been analyzed by other scholars, but in most cases there has been little or no scrutiny of the portrayal of the herpetofauna. Because much of my research as a biologist has focused on reptiles and amphibians, I will consider their differences from mammals and birds. In doing so, I will address image content from a somewhat different point of view than that of an art or science historian. My contention is that understanding the evolving portrayal of these âloathsome beastsâ is particularly useful in tracing the development of the study of natural history. I also will address how changes in these images over time reflect a transformation in how nature was viewed and valued in western European culture. [excerpt
Phylogenetic Analysis of Algal Symbionts Associated with Four North American Amphibian Egg Masses
Egg masses of the yellow-spotted salamander Ambystoma maculatum form an association with the green alga âOophila amblystomatisâ (Lambert ex Wille), which, in addition to growing within individual egg capsules, has recently been reported to invade embryonic tissues and cells. The binomial O. amblystomatis refers to the algae that occur in A. maculatum egg capsules, but it is unknown whether this population of symbionts constitutes one or several different algal taxa. Moreover, it is unknown whether egg masses across the geographic range of A. maculatum, or other amphibians, associate with one or multiple algal taxa. To address these questions, we conducted a phylogeographic study of algae sampled from egg capsules of A. maculatum, its allopatric congener A. gracile, and two frogs: Lithobates sylvatica and L. aurora. All of these North American amphibians form associations with algae in their egg capsules. We sampled algae from egg capsules of these four amphibians from localities across North America, established representative algal cultures, and amplified and sequenced a region of 18S rDNA for phylogenetic analysis. Our combined analysis shows that symbiotic algae found in egg masses of four North American amphibians are closely related to each other, and form a well-supported clade that also contains three strains of free-living chlamydomonads. We designate this group as the âOophilaâ clade, within which the symbiotic algae are further divided into four distinct subclades. Phylogenies of the host amphibians and their algal symbionts are only partially congruent, suggesting that host-switching and co-speciation both play roles in their associations. We also established conditions for isolating and rearing algal symbionts from amphibian egg capsules, which should facilitate further study of these egg mass specialist algae
UPDATED GEOGRAPHIC DISTRIBUTIONS OF MICHIGAN HERPETOFAUNA:: A SYNTHESIS OF OLD AND NEW SOURCES
Recently a comprehensive overview of reptiles and amphibians in Michigan was published. Unfortunately, the distributions of the species represented were compiled before widespread accessibility to technological tools providing greater access to museum and historical records as well as citizen science efforts. To update the known ranges of Michigan herpetofauna, published literature, museum collections, and photographic vouchers submitted to an online database were examined and 339 new county and island records were added, updating the maps for 48 of Michiganâs 55 known species of reptiles and amphibians. I also present the first published list of Michigan amphibians that includes two new plethodontid salamanders, the Northern Dusky Salamander (Desmognathus fuscus) and Southern Two-lined Salamander (Eurycea cirrigera). This paper serves as an example of the wealth of information available to scientists that may have previously been unobtainable, and can be used for the distribution of herpetofauna elsewhere
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