RESUMEN
The activity of hydrolases (maltase, saccharase, amylolytic activity) in the intestinal mucosa of the plankton-feeding zope Ballerus ballerus and the benthos-feeding white-eye bream Ballerus sapa was investigated. The temperature characteristics of maltase hydrolysis (T(opt) and E(act)) are similar in both species. The lower K(m) of maltase hydrolysis in the white-eye bream reflects a higher enzyme/substrate affinity and indicates a more effective carbohydrate hydrolysis in the benthos-versus plankton-feeding species. The glycosidase activity in the white-eye bream is twice as high as in the zope. This may be due not only to different feeding spectra and biochemical food contents but also to the differences in thyroid status of species under consideration.
Asunto(s)
Cyprinidae/metabolismo , Proteínas de Peces , Glicósido Hidrolasas , Mucosa Intestinal/enzimología , Animales , Conducta Alimentaria , Proteínas de Peces/química , Proteínas de Peces/aislamiento & purificación , Proteínas de Peces/metabolismo , Glicósido Hidrolasas/química , Glicósido Hidrolasas/aislamiento & purificación , Glicósido Hidrolasas/metabolismo , PlanctonRESUMEN
An experiment on acceleration and retardation of ontogenesis with thyroid manipulation has revealed direct changes in definitive dentition of pharyngeal bones in Abramis brama bream. As development pace accelerates, the number of teeth reduces to the formula 5-4. When development pace slows down, this number increases to the formula 6-5. Moreover, an additional minor row of teeth (1.6-5.1, 2.6-5.2) is formed. The observed changes transcend typical changes happening in nature. It is assumed that heterochronies provoke changes in the number of teeth.