THE DIGESTIVE TRACT DEVELOPMENT OF THE TIGER GROUPER Epinephelus fuscoguttatus LARVAE TREATED WITH THYROXINE HORMONE
Abstract: Thyroxin
administration in tiger grouper larval rearing was conducted to determine its
effect on development of digestive tract of the larvae. Newly hatched larvae
were treated with 0 mg/L (control), 0.1 mg/L, and 0.2 mg/L of thyroxin for 2
hours in a 30 L tank before were transferred into a 1 m3 rearing tank. Samples
were collected daily until 10 DAH and every 3 days until 40 DAH. Development of
digestive tract was observed using histological method. For all treatments, the
digestive tract was the same on 1 DAH and 2 DAH. The digestive tract of 1 DAH
larvae was still closed and still in the form of a simple tube. The mouth, buccopharynx,
liver, pancreas, and rectum were found on 2 DAH. On 3 DAH, the esophagus,
stomach, intestines, and anus started to develop. At this stage, the digestive
tract of larvae treated with and without thyroxin started to become
distinguishable. Several goblet cells were noticed in the rectum of the treated
larvae but not in the control. Digestive tract developed earlier in treated
larvae compared to the control group, such as appearance of tongue, gill raker,
fundic, and cardiac stomach development, formation of pharyngeal tooth, and
gastric gland. Metamorphosis of larvae into juvenile on treated larvae occurred
than that the control larvae earlier.
Keywords: digestive tract;
Epinephelus fuscoguttatus larvae; thyroxine hormone
Author: Ahmad Muzaki, Ketut
Mahardika, Indah Mastuti, Wawan Andriyanto, Yasmina Nirmala Asih, Ida Komang
Wardana
Journal Code: jpperikanangg120036
