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.
Oto Catfish. These fish are perhaps the best kind of fish that you can get for the purposes of cleaning away algae from the plant matter in your fish tank. Their favorite type of algae to eat is brown algae, something that most other fish will stay away from.
The species in this genus are commonly called algae eaters.. They hold on to fixed objects using a sucker-like mouth, and, despite the name, feed on a wide range of detritus, rather than simply on algae. A golden variety of G. aymonieri, the Chinese algae eater or sucking loach, can be found in many pet shops and fish farms.