Editing Ctenophora (section)

===Body layers ===

[[File:Ctenophore diagram - en.svg|thumb|alt=Anatomy of Cydippid Ctenophore|Anatomy of Cydippid Ctenophore]]

Like those of [[cnidaria]]ns, ([[jellyfish]], [[sea anemone]]s, etc.), ctenophores' bodies consist of a relatively thick, jelly-like [[mesoglea]] sandwiched between two [[epithelium|epithelia]], layers of [[cell (biology)|cells]] bound by inter-cell connections and by a fibrous [[basement membrane]] that they [[secrete]].<ref name="Hinde2001CnidariaAndCtenophoraInAnderson" /><ref name="RuppertBarnes2004Ctenophora"/> The epithelia of ctenophores have two layers of cells rather than one, and some of the cells in the upper layer have several [[cilia]] per cell.<ref name="RuppertBarnes2004Ctenophora"/>

The outer layer of the [[Epidermis (zoology)|epidermis]] (outer skin) consists of: sensory cells; cells that secrete [[mucus]], which protects the body; and interstitial cells, which can transform into other types of cell. In specialized parts of the body, the outer layer contains [[colloblast]]s along the surface of tentacles, used in capturing prey, or cells bearing multiple large cilia for locomotion. The inner layer of the epidermis contains a [[nerve net]], and myoepithelial cells that act as [[muscle]]s.<ref name="RuppertBarnes2004Ctenophora"/>

The internal cavity forms: a mouth that can usually be closed by muscles; a [[pharynx]] ("throat"); a wider area in the center that acts as a [[stomach]]; and a system of internal canals. These branch through the mesoglea to the most active parts of the animal. The inner surface of the cavity is lined with an [[epithelium]], the [[gastrodermis]]. The mouth and pharynx have both [[cilia]] and muscles. In other parts of the canal system, the gastrodermis is different on the sides nearest to and furthest from the organ that it supplies. The nearer side is composed of tall nutritive cells that store nutrients in [[vacuole]]s (internal compartments), [[germ cell]]s that produce eggs or sperm, and [[photocytes]] that produce [[bioluminescence]]. The side furthest from the organ is covered with ciliated cells that circulate water through the canals, punctuated by ciliary rosettes, pores surrounded by double whorls of cilia and connected to the mesoglea.<ref name="RuppertBarnes2004Ctenophora"/>