Abstract:
Puffer fish Tetraodon nigroviridis is able to live in the brackish and sea water.
Sutarman in Purbomartono (2004) stated that the salinity difference affects the
number of goblet and mucous cells in the esophagus wall tissue layer. To understand
the microscopic structure differences of esophagus cell layers of fish from brackish
and saline waters, a study has been conducted in February–August 2012. Fish
samples were collected from the Sei Pakning River (brackish water) and Bengkalis
sea, Riau. The fish’s esophagus was formalin preserved, alcohol series processed, HE
and PAS stained. The type of cells in the esophagus wall layer, the number of
mucous cells and mucous cell area were investigated. Results shown that the
esophagus wall of fish from brackish and sea water consist of 4 tissue layers. There
is similarity in the 1st, 2nd and 4th layers, as they are consisted of mucous layer, sub-
mucosa and serous layers respectively. The 3rd layer, however, is different. There is a
single layer of circular muscle in the brackish fish, but there are a longitudinal
muscle layer in the internal part and a circular muscle layer in the external part of the
esophagus wall of the sea fish. The average of mucous cell area ranges from
0.00043- 0.00046 mm2. The number of mucous cells in the brackish fish is 293
cells/mm2 (19,17% of total area) , while that of the sea fish is 706 cells/ mm 2
(37,16% of total area). The difference of the number and area of the mucous cells
may represent the adaptation effort of the fish toward environmental condition.
