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
Operculum (brain) insula. This process is called opercularization. Opinions differ on whether Albert Einstein’s brain possessed parietal opercula. Falk, et al. claim that the brain actually did have parietal opercula, while Witelson et al. claim that it did not. Einstein's lower parietal lobe (which is involved in mathematical thought, visuospatial cognition and imagery of movement) was 15% larger than average. Figure 9 of Falk 2013 is a photograph of Einstein's right insula after removal of the operculum. (Falk 2013) Operculum (brain) In human brain anatomy, an operculum (Latin, meaning "little lid") (pl. opercula), may refer to the frontal, temporal, or parietal operculum,