Soon after contact with air the only remnants are comb

Flourishing in Eurasia, with no natural predators, sea walnut comb jellies (Mnemiopsis leidyi) are considered to be an undesirable invasive species.A natural remedy is now occurring with the accidental introduction of the pink comb jelly (Beroe ovata), sea wlnut comb helly's natural New World predator, into Eurasia. sea walnut comb jelly, Oslofjord, southeastern NorwayVidar-Aqua-Photos.com, CC BY 2.0, via Flickr Mnemiopsis leidyi is commonly known as sea walnut comb jelly, Leidy's comb jelly, or warty comb jelly. Other scientific synonyms include Mnemiopsis gardeni and Mnemiopsis mccradyi.Its genus name, Mnemiopsis, is derived from two Greek words, Μνήμη, mneme, “memory”, and ὄψις, opsis, “act of seeing, sense of sight”, which, in combination, usually are translated as meaning "unforgettable sight." And, indeed, especially in the dark, sea walnuts are unforgettable.Renowned scientist Alexander Agassiz (December 17, 1835 - March 27, 1910) selected its species epithet, leidyi, to honor Joseph Leidy (September 9, 1823 - April 30, 1891), a physician, vertebrate paleontolgist, and naturalist from Philadelphia, Pennsylvania. Dr. Leidy studied marine invertebrates along the coasts of Rhode Island and New Jersey. President of the Academy of Natural Sciences of Philadelphia for the last eight years of his life, Joseph Leidy published more than 800 scientific papers in his lifetime. Mnemiopsis leidyi: namesake of circumspect, conscientious physician and paleontologist Joseph Leidyca. 1870 portrait by Gilbert Studios, PhiladelphiaPublic Domain, via Wikimedia Commons What is a sea walnut? A sea walnut is a sea dweller in the genus Ctenophora (Greek χτένα, khtena, "comb" + φέρω, pherō, "carry"). Ctenophores characteristically have cilia, or bristles, which are grouped in four double combs, or rows. Movement of the ciliated combs serves to propel the lobed body of the sea walnut through its watery world. Because of their transparency and their distinctive combs, ctenophores are popularly referred to as comb jellies.With water comprising over 95 percent of their body, sea walnuts often delicately disintegrate upon capture and removal from water. Soon after contact with air the only remnants are comb sections with the cilia still beating.Another feature of sea walnuts is their ability to regenerate as long as each fragment represents at least one-fourth of the entire body.Their common name of sea walnut derives from the resemblance of their bodies to a walnut (genus Juglans) both in size and in shape.