scholarly journals Temporal Changes in Concentrations of Some Trace Elements in Muscle Tissue of Crayfish,Astacus leptodactylus(Eschscholtz, 1823), from Keban Dam Lake

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Onder Aksu ◽  
Ragip Adiguzel ◽  
Veysel Demir ◽  
Numan Yildirim ◽  
Durali Danabas ◽  
...  

Crayfish (Astacus leptodactylusEschscholtz, 1823) is the native crayfish species in Turkey. It was exported regularly to Western Europe. In this study, bioaccumulation and temporal trends of some trace elements (arsenic: As, cadmium: Cd, copper: Cu, mercury: Hg, lead: Pb, and zinc: Zn) in edible abdomen muscle of crayfish from Keban Dam Lake (Elazığ, Turkey) were investigated for the 2006–2012 period. Sequence of metal concentration levels was Zn > Cu > Hg > Pb > Cd > As in muscle tissues. The highest concentration of Zn (21.69 mg kg−1) was detected in 2006, while the lowest (4.35 mg kg−1) in 2009. In general, it was found that the concentrations of trace elements investigated were lower than the maximum permissible limits of the food regulations of the Ministry of Food, Agriculture, and Livestock (MFAL), the Turkish Food Codex and Commission Regulation (EC). If the crayfish selected for the study are recognized as bioindicators of environmental pollution, then it is possible to conclude that the changes in studied trace elements concentrations in the Keban Dam Lake are being steady.

NeoBiota ◽  
2020 ◽  
Vol 58 ◽  
pp. 1-32 ◽  
Author(s):  
Johannes C. Rusch ◽  
Michaela Mojžišová ◽  
David A. Strand ◽  
Jitka Svobodová ◽  
Trude Vrålstad ◽  
...  

Crayfish of North American origin are amongst the most prominent high-impact invasive invertebrates in European freshwaters. They contribute to the decline of European native crayfish species by spreading the pathogen causing crayfish plague, the oomycete Aphanomyces astaci. In this study we validated the specificity of four quantitative PCR (qPCR) assays, either published or newly developed, usable for environmental DNA (eDNA) screening for widely distributed native and non-native crayfish present in Central Europe: Astacus astacus, Pacifastacus leniusculus, Faxonius limosus and Procambarus virginalis. We then conducted an eDNA monitoring survey of these crayfish as well as the crayfish plague pathogen in a wide variety of habitat types representative for Central and Western Europe. The specificity of qPCR assays was validated against an extensive collection of crayfish DNA isolates, containing most crayfish species documented from European waters. The three assays developed in this study were sufficiently species-specific, but the published assay for F. limosus displayed a weak cross-reaction with multiple other crayfish species of the family Cambaridae. In the field study, we infrequently detected eDNA of A. astaci together with the three non-native crayfish species under examination. We never detected eDNA from A. astaci together with native crayfish, but in a few locations eDNA from both native and non-native crayfish was captured, due either to passive transport of eDNA from upstream populations or co-existence in the absence of infected crayfish carriers of A. astaci. In the study, we evaluated a robust, easy-to-use and low-cost version of the eDNA sampling equipment, based mostly on items readily available in garden stores and hobby markets, for filtering relatively large (~5 l) water samples. It performed just as well as the far more expensive equipment industrially designed for eDNA water sampling, thus opening the possibility of collecting suitable eDNA samples to a wide range of stakeholders. Overall, our study confirms that eDNA-based screening for crayfish and their associated pathogen is a feasible alternative to traditional monitoring.


2009 ◽  
Vol 10 (2) ◽  
pp. 94-103 ◽  
Author(s):  
Sibtain Rahim ◽  
Linda M. Fredrick ◽  
Barbara A. da Silva ◽  
Barry Bernstein ◽  
Martin S. King

2018 ◽  
Vol 23 (21) ◽  
Author(s):  
Kamilla Laut ◽  
Leah Shepherd ◽  
Roxana Radoi ◽  
Igor Karpov ◽  
Milosz Parczewski ◽  
...  

Background: Direct comparisons between countries in core HIV care parameters are often hampered by differences in data collection. Aim: Within the EuroSIDA study, we compared levels of antiretroviral treatment (ART) coverage and virological suppression (HIV RNA < 500 copies/mL) across Europe and explored temporal trends. Methods: In three cross-sectional analyses in 2004–05, 2009–10 and 2014–15, we assessed country-specific percentages of ART coverage and virological suppression among those on ART. Temporal changes were analysed using logistic regression. Results: Overall, the percentage of people on ART increased from 2004–05 (67.8%) to 2014–15 (78.2%), as did the percentage among those on ART who were virologically suppressed (75.2% in 2004–05, 87.7% in 2014–15). However, the rate of improvement over time varied significantly between regions (p < 0.01). In 2014–15, six of 34 countries had both ART coverage and virological suppression of above 90% among those on ART. The pattern varied substantially across clinics within countries, with ART coverage ranging from 61.9% to 97.0% and virological suppression from 32.2% to 100%. Compared with Western Europe (as defined in this study), patients in other regions were less likely to be virologically suppressed in 2014–15, with the lowest odds of suppression (adjusted odds ratio = 0.16; 95% confidence interval (CI): 0.13–0.21) in Eastern Europe. Conclusions: Despite overall improvements over a decade, we found persistent disparities in country-specific estimates of ART coverage and virological suppression. Underlying reasons for this variation warrant further analysis to identify a best practice and benchmark HIV care across EuroSIDA.


2016 ◽  
Vol 8 (1) ◽  
pp. 96-108 ◽  
Author(s):  
Fabrizio Borghesi ◽  
Enrico Dinelli ◽  
Francesca Migani ◽  
Arnaud Béchet ◽  
Manuel Rendón‐Martos ◽  
...  

2005 ◽  
Vol 26 (3) ◽  
pp. 293-303 ◽  
Author(s):  
Rui Rebelo ◽  
Maria João Cruz

AbstractThe introduction of predators in amphibian breeding habitats may contribute to the decline or extinction of amphibian populations. Procambarus clarkii, a North American crayfish, was recently introduced in the Iberian Peninsula, being now quite abundant in the southwest, a region with no native crayfish species and where 13 amphibian species may be found. We performed mesocosm experiments to evaluate the vulnerability of amphibian embryos and larvae from those species to P. clarkii. Despite the presence of alternative food (vegetation and leaf litter), embryo survival in the presence of P. clarkii was low for all species except Bufo bufo. However, newly hatched B. bufo tadpoles were readily consumed. P. clarkii reduced larval survival in all species, with those species that in nature have few contacts with predators at the larval stage suffering the highest mortalities. Most larvae reduced their activity and/or altered microhabitat use in the presence of P. clarkii, but these behavioural modifications did not lead necessarily to a low vulnerability to predation.


2015 ◽  
Vol 21 (1) ◽  
pp. 115-121
Author(s):  
Hannah Noss ◽  
Wendy Anderson ◽  
Thomas P. Simon

Abstract The Mud River crayfish, Orconectes ronaldi Taylor, is a native crayfish species found in the Midwestern United States in Kentucky and Indiana. Length-weight relationship, body morphometric relationship, and condition within the species native range in south-central Indiana were studied. Growth, size relationships based on gender, sexual phase for adults and juveniles and chelae-length/width relationships were used to interpret patterns in sexual dimorphism. Carapace length (CL)–wet weight (Wwt) relationships for all genders (i.e., male, female, juvenile) and all male forms (form I and II) had positive allometric growth. Male individuals were not significantly heavier than females of the same length. The maximum length and weights of males (35.1 mm CL) were longer and heavier (11.8 g) than the longest female (31.5 mm) weighing 8.3 g. No statistical difference in mean weight was observed; however, this is attributed to the accelerated development of the chelae in sexually mature form I males, whereas chelae of females grow slower throughout life. Chelae length was significantly different between male form II and male form I, and male form II and females (P = 0.004, and P <0.001, respectively). The relatively longer chelae of form I and form II males are due to sexually dimorphic change.


Sign in / Sign up

Export Citation Format

Share Document