Muscle and carapace tissue-diet isotope discrimination factors for the freshwater crayfish Cherax destructor

作者：Mazumder Debashish^*; Johansen Mathew P; Fry Brian; Davis Emma

来源：Marine and Freshwater Research, 2018, 69(1): 56-65.

DOI：10.1071/MF16360

• C-13
• N-15
• crustacean
• non-lethal
• stable isotopes

This study examined a range of diets and two tissue types (muscle and carapace, representing protein and chitin biochemistry respectively) of Cherax destructor (Clark, 1936) to allow more accurate use of isotope data in trophic source estimates. The resulting Delta C-13(tissue-diet) and Delta N-15(tissue-diet) discrimination factors of muscle and carapace tissues showed significant differences among diets. For muscle, Delta C-13(tissue-diet) was higher (2.11-2.33%) when C. destructor was fed with lamb, turkey and mixed animal and plant-based diets, 1.27-1.96% when C. destructor was fed with beef and kangaroo diets and negative (-1.36%) when C. destructor was fed with an aquatic meat (tuna) diet. The Delta N-15(tissue-diet) discrimination factors were lower for muscle when C. destructor was fed aquatic meat (0.12%) and mixed plant-animal diets (1.67%), but higher for terrestrial meat diets (2.79-3.74%). The Delta C-13(tissue-diet) for carapace followed similar patterns to that of muscle, but Delta N-15(tissue-diet) values were lower for carapace than muscle. Strong correlations were observed between muscle and carapace for delta C-13 (r = 0.96, P < 0.0001) and delta N-15 (r = 0.82, P < 0.0012) across the six diets evaluated, indicating that carapace can be used as a non-lethal alternative to muscle during field sampling.

• 出版日期2018