stz = "setzlinge" , german for fingerlings, young… Found some more articles: http://journals.cambridge.org/download.php?file=%2FALR%2FALR15_02%2FS0990744002011531a.pdf&code=3aa8eb42501c5c3ddb323feb4fadd1e3 http://www.bioflux.com.ro/docs/2010.3.362