Beginning of Essay
Introduction The purpose of this lab experiment was to observe and measure the effect of depleting oxygen content in water on the opercular beats and on the gulp trips of Trichogaster trichopterus. Oxygen is an essential element in the daily lives of most organi ....

Middle of Essay
.... hence special problems pertaining to the acquisition of sufficient amounts of oxygen arise for aquatic organisms---namely fish. Fishes have had to develop adaptations that enabled them to adapt to this problem. Since water contains an insufficient concentration of oxygen, fishes use gills to obtain the required amount of oxygen---via the counter-current exchange process. As water enters the mouth of a fish, it passes through slits in the pharynx, flows over the gills, and exits at the back of the operculum (gill cover) (Campbell 1997). This ventilation process serves to bring in a fresh supply of oxygen to the fish and removes carbon dioxide ....