Saxitoxin is produced by the cyanobacteria "Anabaena" spp. The KaiA protein from "Anabaena" sp. This species of the genus "Anabaena" and the domain Eubacteria is capable of photosynthesis. Other genera (e.g. "Anabaena") may be found in both fresh and salt water. The structures are presented as dimers, with the structures from "Sus scrofa" and "Anabaena" sp. Independent carboxyl-terminal domains are the short versions, from the filamentous species "Anabaena" sp. Certain species of "Anabaena" have been used on rice paddy fields. In Florida, these include "Aphanizomenon", "Anabaena" and "Microcystis". Anabaena variabilis is a species of filamentous cyanobacterium. Roots are called "coralloid" with an "Anabaena" symbiosis allowing nitrogen fixation. Further research may be needed to ascertain if "Anabaena azollae" produces neuro-toxins. It was isolated in 1972 by J.P. Devlin from the cyanobacteria "Anabaena flos-aquae". The A-group of the virus causes lysis and infects "Anabaena" species. Anabaena is a genus of filamentous cyanobacteria that exist as plankton. "Anabaena circinalis" exhibits a filamentous morphology, each filament a string of task-specific cells.