Question

how many gills does a piranha have?

Answer 1

piranhas also have 2 gills like other fishes

Answer 2

The skull (or syncranium) of fishes are divided into two basic units, neurocranium (brain case) and branchiocranium. The upper jaw, maxillary and premaxillary bones are attached to the neurocranium. The opercular series is conected to the suspensorium and the hyoid complex to form the gill chamber. This chamber works in unison to allow water to pass through the mouth and ventilate the gills. The gill arch is composed of five bones. Starting at the ventral anterior end of the arch the parts are brasibranchial, hypobrancial, ceratobrancial, and interbrancial. Nearly all fishes have these gills which are composed of cartilaginous or bony tubercles, called gill rakers, which are attached to the inside of the gill arches. The function of the gill rakers has two purposes; protect the delicate gill filaments from foreign particles or to strain out planktonic organisms to be used as food. The blood to these gills are aerated by the rhythmical intake of water of the oral cavity (mouth) and its expulsion through the gill clefts. This then passes the gill filaments. The gill filaments absorb the oxygen and go out as waste byproducts of dissolved gases. The membrane (which can be seen when the fish mouth is open) acts as a valve to prevent water from moving in the wrong direction. If water conditions are bad this can effect the fishes ability to take in oxygen and cause too much carbon dioxide in the blood resulting in labored breathing.

Answer 3

I searched on the web and visited 8-10 sites.......
the above is the best info I cud get about the gills of piranhas.........