The first occurrence of the Australian redclaw crayfish Cherax quadricarinatus (von Martens, 1868) in the contiguous United States

Distribution and establishment of the alien Australian redclaw crayfish, Cherax quadricarinatus, in South Africa and Swaziland

BACKGROUND The Australian redclaw crayfish (Cherax quadricarinatus, von Martens), is native to Australasia, but has been widely translocated around the world due to aquaculture and aquarium trade. Mostly as a result of escape from aquaculture facilities, this species has established extralimital populations in Australia and alien populations in Europe, Asia, Central America and Africa. In South...

Distribution and establishment of the alien Australian redclaw crayfish, Cherax quadricarinatus, in South Africa and Swaziland

Natural infection of the redclaw crayfish Cherax quadricarinatus with presumptive spawner-isolated mortality virus.

Crayfish farmers reported reduced tolerance of stress in specimens of Cherax quadricarinatus, which were formerly robust crayfish. Furthermore, one farmer reported a large reduction in yield with final harvest only equaling the stocking weight. Upon trapping, one-third of the crayfish regularly died overnight and a further one-third died on the sorting tray during sexing of juveniles (approxima...

Direct Age Determination of a Subtropical Freshwater Crayfish (Redclaw, Cherax quadricarinatus) Using Ossicular Growth Marks

Recent studies have reported that crustacean age determination is possible. We applied a direct ageing method (i.e. transverse cross sectioning of gastric ossicles) to a subtropical freshwater crayfish (Cherax quadricarinatus) sourced from an aquaculture population. Growth mark periodicity and the potential for chronological depositions were investigated by staining C. quadricarinatus with calc...

romantic education:reading william wordsworths the prelude in the light of the history of ideas

عصر روشنگری زمان شکل گیری ایده های مدرن تربیتی- آموزشی بود اما تاکید بیش از اندازه ی دوشاخه مهم فلسفی زمان یعنی عقل گرایی و حس گرایی بر دقت و وضوح، انسان عصر روشنگری را نسبت به دیگر تواناییهایش نابینا کرده و موجب به وجود آمدن افرادی تک بعدی شد که افتخارعقلانیتشان، تاکید شان بر تجربه فردی، به مبارزه طلبیدن منطق نیاکانشان وافسون زدایی شان از دنیا وتمام آنچه با حواس پنجگانه قابل درک نبوده و یا در ...