User:Jtwsaddress42/Quotes/Cavalier-Smith, Thomas 2017a

From Nematocysts to Post Synaptic Cleft "'The larger larvae of true sponges provided a novel, hitherto unexploited, food for predators. One stem sponge lineage, I suggest, evolved nematocysts to catch and digest them, thereby becoming the ancestor of coelenterates (Cnidaria, Ctenophora), a clade on the best multigene trees. Nematocyst discharge of ECM anchors the aboral pole of settling cnidarian planula larvae just as do secretory flask cells at the aboscular pole (similarly anterior when swimming) of sponge larvae. Flask cells are the only larval sponge cell type to coexpress the majority of post-synaptic protein homologues, so I suggest, evolved directly into nematocytes by evolving capsular/tube minicollagens and cnidoin elastomer that facilitates their nanosecond discharge.' - Thomas Cavalier-Smith (2017)"