Cookies Policy

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies.

I accept this policy

Find out more here

Activities of Three Digestive Enzymes During Development in the Crayfish Procambarus Clarkii (Decapoda)

No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
The full text of this article is not currently available.

Brill’s MyBook program is exclusively available on BrillOnline Books and Journals. Students and scholars affiliated with an institution that has purchased a Brill E-Book on the BrillOnline platform automatically have access to the MyBook option for the title(s) acquired by the Library. Brill MyBook is a print-on-demand paperback copy which is sold at a favorably uniform low price.

This Article is currently unavailable for purchase.
Add to Favorites
You must be logged in to use this functionality

Cover image Placeholder

Abstract Enzyme extracts were used to characterize α-amylase-, trypsin-, and nonspecific-esterase-specific and total activities during the early life-history stages of the red swamp crayfish Procambarus clarkii. Significant increases in the specific activities of all three digestive enzymes were observed prior to the onset of feeding, suggesting that digestive competence is attained prior to feeding and appears to be controlled genetically. After the onset of feeding, the digestive-enzyme-specific and total activity increased steadily through the 42nd day of development, after which point activity did not change significantly. We hypothesize that the observed increase in specific activity reflects the maturation of the hepatopancreas, as greater amounts of digestive enzymes are being produced per unit weight of tissue. As individuals exceeded approximately 100 mg in total weight, specific activity was variable and did not change substantially. Further increases in total enzyme activity (total digestive capacity) were dependent primarily on increases in the weight gain of the individual. We suggest that the first four to six weeks of development may represent a crucial stage in the development of the hepatopancreas and that perturbations that occur during this stage of development may impact future growth. The pattern of digestive enzyme expression in Procambarus clarkii indicates little or no change in nutritional requirements and is different from the patterns observed in decapod crustaceans that have planktotrophic life-history stages. The digestive enzyme activities indicate that crayfish can digest and utilize primarily carbohydrates, proteins and, to a lesser extent, lipids as macronutrients during early growth.

Affiliations: 1: Department of Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294–1170, U.S.A.


Full text loading...


Data & Media loading...

Article metrics loading...



Can't access your account?
  • Key

  • Full access
  • Open Access
  • Partial/No accessInformation