Tetra a tall dorsal fin characterized by a short connection to the fish’s body. Additionally, tetras possess a long anal fin stretching from a position just posterior of the dorsal fin and ending on the ventral caudal peduncle, and a small, fleshy adipose fin located dorsally between the dorsal and caudal fins. This adipose fin represents the fourth unpaired fin on the fish (the four unpaired fins are the caudal fin, dorsal fin, anal fin, and adipose fin), lending to the name tetra, which is Greek for four. While this adipose fin is generally considered the distinguishing feature, some tetras (such
Caudal cell mass The cavities formed from the initial and secondary neuralation combine to form one uninterrupted cavity. There is still specualtion on the formation of the caudall cell mass in humans with arguments being made for it arising from many cavities or the continuing growth of the neurocele from the initial neuralation. The caudal cell mass will ultimately differentiate and form into many sacral structures such various nerve endings and the conus medullaris. The caudal cell mass plays a role in many diseases and abnomalities related to the spinal cord. One group of abnormalities it plays a role in are occult spinal