The term Protostomia (from the Greek "proto," meaning first, and "stoma," meaning mouth) was coined by the biologist Karl Grobben in 1908. They are a subtaxon of the Bilateria, and are contrasted with the deuterostomes.Protosomes are distingued by their embryo: in deuterostomes, the first opening (the blastopore) becomes the anus, while in protostomes it becomes the mouth. English. Grammar. Deuterostomes are a large superphylum of animals that includes chordates (vertebrates), echinoderms, hemichordates (acorn worms), and one small phyla, Xenoturbellida, which consists of two marine worm-like species. If you want to know if a jellyfish is an invertebrate, it is best if you to try to answer this question yourself. Protostome definition: a mollusc , annelid , arthropod or other animal in which the mouth develops before the... | Meaning, pronunciation, translations and examples. Originally Answered: is the jellyfish invertebrate ? Log In Dictionary. They belong to the group Protostomia, a type of inferior invertebrate in which the mouth... See full answer below. Origin of Protostomia. Author information: (1)Department of Biology and Geosciences, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585, Japan. Nagata T(1), Koyanagi M, Tsukamoto H, Terakita A. Identification and characterization of a protostome homologue of peropsin from a jumping spider. What is a protostome. Protostomes are a nephrozoan taxon of animals above the level of phylum.It is not part of the normal system of classification.. The gills slits are modified in the adult form to allow filter feeding. The gills slits are modified in the adult form to allow filter feeding. "Deuterostome" means "second mouth organism," a reference to the fact that during embryological development in deuterostomes, the first body opening becomes the anus, and … In science and maths it is sometimes best to think about a question, understand the words that are used , then try to figure out the answer for yourself. The Deuterostome shows radial cleavage at the eight-cell embryonic stage and forms its anus directly from the blastopore . Sat, 24 Dec 2016 | Dermatology Therapy. These invertebrate organisms are usually sessile and possess a U-shapes gut and two siphons, which allows them to take in food. A protostome comes from the Greek that means 'mouth-first'. Translator. The Protostome shows spiral cleavage at the eight-cell embryonic stage and forms its mouth directly from the blastopore. Dictionary Grammar Blog School Scrabble Thesaurus Translator Quiz More Resources More from Collins. Thesaurus.