Nakhustdahonho

Nakhustdahonho (Protostomia), guruhi hayvonhoi bemukhra, ki pahnkirmho(Plathelminthes), nemertinho (Nemertini), halqakirmho (Annelides), narmbadanho (Mollusca), bandpoyho (Arthropoda) va gayraroro darbar megirand. Inkishofi Nakhustdandonho chunin ast: dar joi dahoni nakhustin (blastopora) yo dar qismi peshi on suro- khii dahon va dar okhiri tana surokhii pusht ba vuchud meoyad.