delusion of negation (nihilistic delusion) a depressive delusion that the self, part of the self, part of the body, other persons, or the whole world has ceased to exist. paranoid d's an older term for delusion of grandeur and delusion of persecution; its use is discouraged. delusion of persecution a delusion that one is being attacked, harassed, cheated, persecuted, or conspired against. It is one of the subtypes of delusional disorder.
Soft Green Algae. The main food of Otocinclus is algae. They will eat the soft green algae that grows on the surfaces of the tank and its contents. This surfaces include the inside of the tank walls, gravel, decorations, and plants. This soft algae isn't to be confused with green spot algae that you can barely get off with a razor blade.
There are 7 main types of algae (but more do exist) that aquariums can have. Brown algae. Brown Algae. This will probably be the first type of algae any one will encounter in the aquarium and could appear from early on and will normally disappear when the tank stabilises and becomes more mature. Brown algae could be in the form of a fluff like or spot appearance on plant leaves, rocks, glass, substrate or decorations.