Kouba and colleagues, 2014

Kouba A, Petrusek A, Kozák P. 2014. Continental-wide distribution of crayfish species in Europe: update and maps. Knowledge and Management of Aquatic Ecosystems 413: 05. http://dx.doi.org/10.1051/kmae/2014007

Abstract

Recently published astacological studies substantially improved available data on distribution of crayfish in various European regions. At the same time, spread of invasive species has been recorded, additional non-indigenous species became established in various countries, and losses of populations of native species due to crayfish plague and other negative factors were observed. We overview recent advances in this knowledge, and provide updated colour maps of the distribution of all crayfish species present in Europe. These maps are originally based on the data from the Atlas of Crayfish in Europe published in 2006 as a result of the CRAYNET project, and were further updated from more recently published reports, grey literature, and especially thanks to contributions and feedback of over 70 specialists from 32 countries. Separate maps are available for all indigenous crayfish species in Europe as well as for three most widespread non-indigenous crayfish species. Additionally, two maps give locations of known findings of crayfish species introduced to Europe after 1980. These newly established alien species have so far restricted distributions; however, the frequency of recent reports suggests that findings of such species resulting from releases of aquarium pets will further increase.

Keywords: crayfish distribution • indigenous species • invasive species • native range • maps

Soedarini and colleagues, 2014

Soedarini B, van Gestel CAM, van Straalen NM, Widianarko B, Röling WFM. 2013. Interactions between accumulated copper, bacterial community structure and histamine levels in crayfish meat during storage. Journal of the Science of Food and Agriculture 94(10): 2023-2029. http://dx.doi.org/10.1002/jsfa.6519

Abstract

Background

Pollution in aquaculture areas may negatively impact edible species and threaten seafood quality and safety. The aim of this study was to determine the interaction between copper and bacteria in the aquatic habitat and their impact upon crustaceans. Marbled crayfish was chosen as a model of aquatic crustaceans and the influence of metal contamination on bacterial community structure in water used to culture crayfish and in crayfish themselves was investigated. Histamine, an allergen commonly formed by certain groups of bacteria in crustacean's edible tissue during storage, was also determined.

Results

Copper exposure increased its concentration in crayfish meat by 17.4%, but the copper concentration remained within acceptable food safety limits. Elevated copper levels affected the bacterial community both in the water used to cultivate crayfish and in the marbled crayfish themselves. Cluster analysis of 16S rRNA-gene based microbial community fingerprints revealed that copper impacted the bacterial community in the water and in the crayfish meat. However, copper exposure reduced the formation of histamine in crayfish meat during storage by 66.3%.

Conclusion

Copper from the habitat appears to reduce histamine accumulation in crayfish meat during storage by affecting the bacterial community structure of the cultivation water and most likely also in the intestines of the crayfish. From a food safety point of view, copper treatment during the aqua culturing of crustaceans has a positive impact on the postharvest stage.

Keywords: copper • bacterial community structure • histamine • crayfish • storage