Nerve net Nerve net A nerve net consists of interconnected neurons lacking a brain or any form of cephalization. While organisms with bilateral body symmetry are normally associated with a central nervous system, organisms with radial symmetry are associated with nerve nets. Nerve nets can be found in members of the Cnidaria, Ctenophora, and Echinodermata phyla, all of which are found in marine environments. Nerve nets can provide animals with the ability to sense objects through the use of the sensory neurons within the nerve net. The nerve net is the simplest form of a nervous system found in multicellular organisms. Unlike
Bacterial phyla Gram positive bacteria, many of which are notable secondary metabolite producers. There are only two phyla of monoderm Gram positive bacteria, the other being the "Firmicutes"; the actinobacteria generally have higher GC content so are sometimes called "high-CG Gram positive bacteria". Notable genera/species include "Streptomyces" (antibiotic production), "Propionibacterium acnes" (odorous skin commensal) and "Propionibacterium freudenreichii" (holes in Emmental) The "Aquificae" (diderm Gram negative) contains only 14 genera (including Aquifex and Hydrogenobacter). The species are hyperthermophiles and chemolithotrophs (sulphur). According to some studies, this may be one of the most deep branching phyla. The "Bacteroidetes" (diderm Gram negative) is a member