Conservation genetics of two endangered unionid bivalve species: Epioblasma florentina walkeri and Epioblasma capsaeformis (Unionidae: Lampsilini)

Journal Molluscan Studies 01/2002; 68:385-391.
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    ABSTRACT: High concentrations of tetrodotoxin (TTX) have been detected in some New Zealand populations of Pleurobranchaea maculata (grey side-gilled sea slug). Within toxic populations there is significant variability in TTX concentrations among individuals, with up to 60-fold differences measured. This variability has led to challenges when conducting controlled laboratory experiments. The current method for assessing TTX concentrations within P. maculata is lethal, thus multiple individuals must be harvested at each sampling point to produce statistically meaningful data. In this study a method was developed for taking approximately 200 mg tissue biopsies using a TemnoEvolution® 18G × 11 cm Biopsy Needle inserted transversely into the foot. Correlation between the TTX concentrations in the biopsy sample and total TTX levels and in individual tissues were assessed. Six P. maculata were biopsied twice (nine days apart) and each individual was frozen immediately following the second sampling. Tetrodotoxin concentrations in biopsy samples and in the gonad, stomach, mantle and the remaining combined tissues and fluids were measured using liquid chromatography-mass spectrometry. Based on the proportional weight of the organs/tissues a total TTX concentration for each individual was calculated. There were strong correlations between biopsy TTX concentrations and the total (r(2) = 0.88), stomach (r(2) = 0.92) and gonad (r(2) = 0.83) TTX concentrations. This technique will enable more robust laboratory studies to be undertaken, thereby assisting in understanding TTX kinetics, ecological function and origin within P. maculata.
    Toxicon 08/2013; · 2.58 Impact Factor
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    ABSTRACT: The roles of systematics,in the field of conservation,biology are well understood,and accepted,for many organisms. However, the role of systematics and taxonomy has not been reviewed in the context of species protection and,management,of freshwater,gastropods. We provide,a thorough,review,of the relevant theoretical literature in systematics,and,taxonomy,and illustrate with recent examples,of species delineation and,taxonomy,in North American,freshwater,gastropods,that these fields play key,roles in the practical designation,of conservation,management,units. We summarize,some,aspects of the biology,of freshwater gastropods that can confound taxonomic and management efforts. Based on our review, we recommend that effective conservation,plans,include,the systematic,research,necessary,to recognize,unique,organismal lineages as primary,conservation,management,units. This strategy must,be combined,with consistent and rigorous nomenclature, taxonomy, and dissemination of research findings so that all parties have access to the highest quality information. Key words: systematics, taxonomy, snail, freshwater, conservation, gastropods. Rigorous systematic,and,taxonomic,efforts provide
    Journal of The North American Benthological Society - J N AMER BENTHOL SOC. 01/2008; 27(2):471-483.
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    ABSTRACT: Non-lethal DNA sampling has long appealed to researchers studying population and conservation genetics, as it does not necessitate removing individuals permanently from their natural environment or destroying valuable samples. However, such an approach has not yet been well established in bivalves. In this study, we demonstrate that the gill represents a good source of tissue for non-lethal sampling in scallops. Removal of a few gill filaments caused no noticeable behavioral abnormalities or increased mortality rates in Zhikong scallop (Chlamys farreri) during a three-month period of observation. To facilitate rapid gill-based DNA extraction, six methods (MA-MF) were designed and evaluated, each requiring less than one hour of processing time. The optimal method was identified as MF, in terms of maintaining DNA integrity and genotyping accuracy. Further optimization of MF method by orthogonal experimental design suggested that the utilization of gills could be limited to 2 mg of sample, which is sufficient for performing up to 20,000 PCR reactions. We also demonstrate the excellent cross-species utility of MF in two additional scallop species, Yesso scallop (Patinopecten yessoensis) and bay scallop (Argopecten irradians). Taken together, our study provides a rapid and efficient approach for applying non-lethal DNA sampling in bivalve species, which would serve as a valuable tool for maintaining bivalve populations and conservation genetics, as well as in breeding studies.
    PLoS ONE 07/2013; 8(7):e68096. · 3.53 Impact Factor


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May 28, 2014