Morphology and morphometry of the digestive system of the channel catfish raised in captivity

Abstract

Longed to evaluate macroscopic and morphology characteristics of channel catfish’s digestive
system correlating them with feeding habit. Were used 26 specimens of healthy channel
catfish, with an average weight of 606 grams. After capture and 24 hours of fasting, the
animals were euthanized through anesthesia containing benzocaine in concentration of
50mg/kg followed by spinal cord transverse section. Morphologic and topographic
evaluations of buccopharyngeal cavity, feeding canal and accessory glands were carried out.
Presence of wide oral cleft, oral and pharyngeal teeth, esophagus with a large number of
longitudinal folds, developed stomach with highly folded mucosa were observed, several
convolutions were noted at the posterior intestine. As for morphometry, standard and
intestinal lengths were determined and the Intestine Relative Length (IRL) was calculated.
There were no significative differences of average IRL between the groups. It can be mentioned that channel catfish has morphologic and morphometric characteristics that are
compatible to the ones of other omnivorous fishes with piscivorous tendency. Nevertheless,
this study may indicate that this specie is under adaptation period to a new feeding habit, due
to some sort of environment pressure.