Premium
The adaptation of digestive enzymes to temperature, season and diet in roach, Rutilus rutilus and rudd Scardinius erythrophthalmus ; Proteases
Author(s) -
Hofer R.
Publication year - 1979
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/j.1095-8649.1979.tb03619.x
Subject(s) - rutilus , biology , proteolytic enzymes , detritus , proteases , zoology , invertebrate , fish <actinopterygii> , adaptation (eye) , protease , natural food , ecology , enzyme , fishery , food science , biochemistry , neuroscience
The seasonal changes of proteolytic activity in the gut content of roach R. rutilus and rudd S. erythrophthalmus in four Tyrolean lakes and the adaptation of the proteases to constant temperatures and different natural diets were studied. In rudd proteolytic activity remains nearly constant throughout the year. In roach proteolytic activity increases and then decreases during the first three months after the thaw in spring. This period appears to be endogenously controlled and is followed by a second stage in which proteolytic activity is influenced by environmental factors. Under natural conditions both species have a higher proteolytic activity when feeding on animals than on detritus. Under laboratory conditions there is a slight maximum at an environmental temperature of 16° C when the fish had been fed on meal worms. With plant food a significant dependence of proteolytic activity on environmental temperature was only found in roach.