Ontogeny of digestive and immune system
organs of larval and juvenile kelp grouper Epinephelus bruneus reared
in the laboratory
K. Kato, K.
Ishimaru, Y. Sawada, J. Mutsuro, S. Miyashita, O. Murata, H. Kumai-2004
Fisheries Science, 70(6):
1061-1069
Abstract:
A histological examination was made of the ontogenetic development of the
digestive and immune systems of the larval and juvenile kelp grouper Epinephelus
bruneus reared in the laboratory. The liver, gall bladder, pancreas and
the demarcating region between the intestines and rectum were formed within
3 days post-hatch (dph). During the preflexion phase (within 16 dph),
revolution of the intestine concluded, and pharyngeal teeth and the mucous
cells of the esophagus were differentiated. In the transitional period to
the juvenile stage (25 dph), the blind sac of the stomach, gastric
glands and pyloric caeca began to form. From the viewpoint of the
differentiation phase of the adult-type digestive system, the kelp grouper
is similar to Heterosomata, hitherto reported. The primordial thymus, kidney
and spleen were present at 12, 1 and 6 dph, and the small lymphocytes
in these lymphoid organs appeared at 21, 30 and 33 dph, respectively.
The developmental sequence of the lymphoid organs and the appearance ages of
the lymphoid organs and small lymphocytes in the lymphoid organs in the kelp
grouper are similar to those of other marine fish previously reported,
except for the Pacific bluefin tuna Thunnus orientalis.