Open AccessNatural Stable Isotopes for Determination of Gastrointestinal Transit Time in Fish
Author(s) -
de Sandre Lidiane Cristina Gonçalves,
Buzollo Hellen,
do Nascimento Thiago Matias Torres,
Neira Lígia Maria,
Abimorad Eduardo Gianini,
Jomori Rosangela Kiyoko,
Ducatti Carlos,
Portella Maria Célia,
Carneiro Dalton José
Publication year - 2016
Publication title -
journal of the world aquaculture society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.655
H-Index - 60
eISSN - 1749-7345
pISSN - 0893-8849
DOI - 10.1111/jwas.12244
Subject(s) - pacu , biology , isotopes of carbon , stable isotope ratio , piaractus mesopotamicus , feces , isotope , fish <actinopterygii> , carbon fibers , zoology , ecology , fishery , materials science , total organic carbon , physics , quantum mechanics , composite number , composite material
This study evaluated the application of stable isotopes of carbon as an alternative and more accurate method to determine gastrointestinal transit time ( GTT ) in fish by comparing it to the inert marker method. The stable isotope method detects alterations of the normal carbon flow in a biological system by analyzing naturally occurring isotopes of carbon, contrary to studies based on conventional techniques that apply external markers to the diet to determine GTT through visual observation of the color change in feces. Therefore, 320 pacu, Piaractus mesopotamicus juveniles were reared in 32 tanks under two different temperatures (25 and 29 C). The pacu juveniles received two different diets, one based on ingredients derived from C 3 photosynthetic cycle plants and the other based on C 4 plant ingredients, both containing titanium oxide ( TiO 2 ) as a marker. After 40 d, the isotopic signature of the diets was changed, and the marker was replaced by chromic oxide ( Cr 2 O 3 ). In the isotopic technique, the feces were analyzed to determine the exchange in the isotopic ratio of carbon δ 13 C . Both methods found that GTT was faster (nearly 6 h) in fish at 29 C when using the C 4 / C 3 feeding strategy and slower in fish at 25 C using the C 3 / C 4 strategy (15 h by inert marker and 18 h by the isotopic method). In conclusion, GTT determination in pacu juveniles using the stable isotope technique exhibits the same accuracy obtained with the inert marker method at temperatures suitable (nearly 29 C) for the metabolism of these animals.