Arachnology
Entomology
Invertebrate Zoology
Vertebrate Zoology
Word Roots
Strange Tales
Rokes and Jiddles
A Dictionary for Invertebrate Zoology
Head Words - O
Oak Galls (Oak Apples), Oarium, Obcompressed, Obconic/Obconical, Obcordate (Obcordiform), Obcurrent, Obdeltoid, Obelia, Obese, Obex (Obices), Obimbricate, Oblanceolate, Oblate, Obligate, Obligate Brood Reduction, Obligate Gamete, Obligate Parasite, Obligate Symbiont, Oblique, Oblique Muscles, Oblique Vein, Obliquus, Obliterate, Obliterative Coloration (Obliter-Ative Shading, Countershading), Oblong Plates, Oblongum, Obovate, Obovoid, Obpyriform, Obscure, Obsite, Obsolescence, Obsolete, Obtect, Obtected, Obtect Pupa, Obturaculum, Obturator, Obtuse, Obtusilingual, Obtusilingues, Obumbrate, Obverse, Obvolvent, Occasional Species, Occipital, Occipital Arch, Occipital Carina, Occipital Cilia, Occipital Condyles (Cervical Condyle), Occipital Foramen, Occipital Ganglion, Occipital Margin, Occipital Notch, Occipital Region, Occipital Sulcus, Occipital Suture, Occipital Tentacle, Occipitalia, Occiput, Occludent Margin, Occludent Teeth, Occlusal, Occlusion, Occlusion Plate, Occlusor Muscle, Occult, Oceania, Oceanic, Oceanic Biome, Oceanic Island, Oceanic Zone, Oceanophilus, Ocellar, Ocellar Basin, Ocellar Bristles, Ocellar Bulb, Ocellar Centers, Ocellar Group, Ocellar Pair, Ocellar Pedicels, Ocellar Plate, Ocellar Triangle, Ocellata, Ocellate, Ocellated (Ocelliferous), Ocellus, Ochraceous, Ochroleucous, Ochrophore, Ochteridae (Pelogonidae), Ochthiphilidae, Ocneriidae, Ocnerodrilidae, Octactine, Octactinellida, Octad, Octameros, Octant, Octocorallia (Alcyonaria, Octoradiata), Octoploid, Octopod, Octopoda, Octoprostatic, Octoradiata, Octoradiate, Octothecal, Octozoic, Ocular, Ocular Bulla, Ocular Emargination, Ocular Fleck, Ocular Fringe, Ocular Lobe, Ocular Papilla, Ocular Peduncle, Ocular Plates, Ocular Points, Ocular Sclerites, Ocular Seta, Ocular Sinus, Ocular Suture, Ocular Tube, Ocular Tubercles, Ocularium, Oculate, Oculiferous (Oculigerous), Oculo-Antennary Segment, Oculofrontal, Oculomotor, Oculus, Ocypodidae (Ghost Crabs), Odonata (Devil’s Darning Needles, Horse-Stingers), Odonate, Odontium, Odontoblast (Odontoplast), Odontoceridae, Odontoid, Odontophore, Odontoplast, Odontostyle, Odontostylet, Odoriferous Glands, Odorimetry, Odoriphore (Osmophore), Odor Trail, Oecad, Oecesis, Oecise (Ecize), Oecium, Oeco-, Oecoid, Oecology, Oecoparasite, Oecophene, Oecophoridae, Oecophylla Leakeyi, Oecotrophobiosis, Oedaeagus, Oedeagus, Oedoeagus, Oedematin, Oedemeridae, Oedicerotidae, Oegophiurida, Oegopsida, Oenocyte, Oenocytoid, Oeruginous, Oeruginus, Oesophageal Bulbs, Oesophageal Glands, Oesophageal Pouches, Oesophageal Sclerite, Oesophageal, Oesophagus (Esophagus), Oesophastome (Esophastome), Oestridae, Official Index, Official List, Ogival, -Oidea, Oike, Oikesis, Oikoid, Oikology, Oikosite, Oil Beetle, Oil Gland, Oleocyst, Oleoplast, Oleosome, Olethreutidae, Olfaction, Olfactory, Olfactory Cone, Olfactory Hair, Olfactory Lobes, Olfactory Organs, Olfactory Papilla, Olfactory Pits, Olfactory Pores, Olfactory Receptors, Olfactory Sacs, Olfactory Spindle (Lobus Osphradicus), Oligacanthorhynchida, Oligacanthous, Oligobrachiidae, Oligocene, Oligochaeta, Oligodendrocytes (Oligodendroglia, Oligoglia), Oligodynamic, Oligoentomata, Oligogene, Oligogenic, Oligoglia, Oligogyny, Oligogyral, Oligohaline, Oligolecithal Egg, Oligolectic, Oligolobate, Oligomerization, Oligomerous (Oligomery), Oligomictic, Oligonephrous, Oligoneura, OLIGONEURIIDAE, Oligoneuroptera (Oligoneoptera), Oligophagous, Oligophyletic, Oligopneustic, Oligopod, Oligopyrene, Oligosaprobic, Oligotaxy, Oligothermic, Oligotokous, Oligotrichy, Oligotrophic, Oligotropic, Oligotypic, Oligoxenous, Oligozoic, Olistherozones, Olivaceous, Oliviform, Olophoridae, Olynthus, Omaniidae, Ombrotiphic, Omega-Ramule, Ommata, Ommateum, Ommatidium, Ommatochrome, Ommatoids, Ommatophore (Ophthalmophore), Ommochromes (Ommachromes, Ommatochromes), Omnispective Classification, Omnivorous (Pantophagous), Omphalian, Omphalium, Omphaloid, Omphalous, Omphralidae, Onchial Plate, Onchidiidae, Onchiophore, Onchiostyle, Onchium (Onchia), Onchomiracidium, Onchosphere, Oncomiracidium (Onchomiracid-Ium), Oncophysis, Oncopoduridae, Oncosphere (Onchosphere), Oniscidae, Onisciform, Oniscoidea, Oniscomorpha, Ontocycle, Ontogenetic Allometry, Ontogenetic Migration, Ontogeny (Ontogenesis, Ontogen-Etic), Onuphidae, Onychaetes, Onyches, Onychii, Onychium, Onychiuridae, Onychogenic, Onychophora (Prototracheata, Velvet Worms), Onychopoda, Onychoteuthidae, Ooapogamy, Ooblast, Ooblastema, Oocapt, Oocyte (Ovocyte), Oocytin, Ooecial Vesicle, Ooeciostome, Ooecium (Ovicell), Oogamete, Oogamy, Oogenesis (Ovogenesis), Oogenotop, Oogloea, Oogonium (Oogone), Ooid, Ookinesis, Oolemma, Oophagous, Oophore, Ooplasm (Ovoplasm), Ooplast (Oosphere), Oopod, Oosperm, Oosphere, Oospore, Oostegapod (Oostegopod), Oostegite, Ootheca (Ovicapsule), Ootid Nucleus, Ootid, Ootocoid, Ootocous, Ootype, Ooze, Oozoid, Opaline, Opaque, Open Cell, Open Coxal Cavity, Open Population, Open System, Operant Conditioning, Operational Taxonomic Unit (OTU), Opercular Membrane, Opercular Plug Or Spot, Opercular Scar, Opercular Valves, Operculate (Operculiferous), Operculiform, Operculigenous, Operculigerous, Operculum, Opercula, (Opercle), Opesia, Opesiule, Opesium, Opheliidae, Ophiocistioidea, Ophiomyxina, Ophiopluteus, Ophirhabd, Ophiuridea (Ophiurida), Ophiuroid, Ophiuroidea (Ophiurae), Ophryon, Ophthalmic, Ophthalmic Somite, Ophthalmic Scale, Ophthalmocercaria, Ophthalmogyric, Ophthalmophore, Ophthalmopod, Ophthalmotheca, Opiliones (Phalangida), Opisthandria, Opisthaptor (Opsithohaptor), Opisthion, Opisthobranchia (Opisthobranch-Iata), Opisthocline, Opisthocont (Opisthokont), Opisthocyrt, Opisthodelphic, Opisthodetic, Opisthogenesis, Opisthoglossal, Opisthognathous, Opisthogoneata, Opisthogoneate, Opisthogonia, Opisthogyrate, Opisthohaptor, Opisthokont, Opisthomere, Opisthomerite, Opisthoparamere, Opisthopora, Opisthorchiida, Opisthosoma, Opisthosomatal Plate, Opisthosomatic Appendages, Opisthosomatic Scissure, Opisthospermophora (Juliformia), Opisthothelae, Opistocystidae, Oplophoridae, Opomyzidae, Opophilous, Opossum Shrimps, Opostegidae, Opportunist Pathogen, Opportunistic Species, Opsiblastic, Opsigenes, Optic, Optic Gland, Optic Lobes, Opticon, Optimum Foraging Theory, Optimum Yield (Maximum Sustained Yield), Optimum, Optomotor, Orad, Oral, Oral Arms, Oral Cavity, Oral Cone, Oral Disc, Oral Fimbria, Oral Hooks, Oral Lappet (Labial Veil), Oral Lobe, Oral Plate, Oral Segment, Oral Spear, Oral Styles, Oral Surface, Oral Tentacles, Oral Valve, Oral Vibrissae, Orb, Orbicular, Orbicularis, Orbiculate, Orbiniidae, Orbit, Orbital Bristles, Orbital Carina, Orbital Fossa, Orbital Hiatus, Orbital Plate, Orbital Region, Orbital Tooth, Orb-Web Spiders, Orchitic, Order, Orders of Radiae, Ordinal, Ordinate, Ordinatopunctate, Ordovician, Oreillets (Auricles), Organ, Organelles (Organellae), Organic, Organific, Organism, Organizer (Organization Centre), Organ of Bellonci (Frontal Organ, X-Organ, Rod-Shaped Organ), Organ of Berlese, Organ of Bojanus, Organ of Hicks, Organ of Hoyle, Organ of Johnston, Organ of Keber, Organ of Kölliker, Organ of Ribaga, Organ of Tömösvary, Organs of Valenciennes, Organogenesis (Organogeny), Organogenic, Organography, Organoid, Organoleptic, Organomymy, Organonomy, Organophyly, Organoplastic, Organotroph, Organotypic, Organ-Pipe Coral, Organs of Golgi, Organ Specific Areas, Organule, Oribatida (Cryptostigmata), Orichalceous, Oriental Faunal Region (Realm), Orientating Response, Orientation, Orifice (Orificium), Orificial Wall, Ornamentation, Ornate Cercaria (Cercariae Ornatae), Orneodidae, Ornithocoprophilous, Ornithocopros, Ornithogaea, Oroanal, Orogenic Activity, Orphan Nest, Ortet, Orthal, Orthandria, Orthezidae, Orthida, Orthocerous Condition, Orthocline, Orthoconic, Orthodont Hinge, Orthodromic, Orthogenesis (Determinate Evolution), Orthognatha, Orthognathous, Orthograde, Orthogyral, Orthogyrate, Orthokinesis, Orthologous, Orthometaneme, Orthonectida, Orthoneury, Orthoploid, Orthopoda, Orthoptera, Orthopteroidea, Orthoradial, Orthorrhapha, Orthoselection, Orthosomatic, Orthospiral (Plectonemic), Orthostasy, Orthostrophic, Orthotaxy, Orthotriaenes, Orthotrichy, Orthotype, Ortstreue, Orussidae, Orussoidea, Oryctology (Oryctics), Os, Ora, Oscula, Osculant, Oscular, Oscular Chimney, Oscular Sphincter, Osculate, Osculiferous, Osculum, Osmeterium, Osmium, Osmoconformers, Osmomorphosis, Osmophore, Osmoreceptors, Osmoregulation, Osmorphosis, Osmosium, Osmotaxis, Osmyl, Osmylidae, Osphradium, Ossicle, Ossiculum, Ostia, Ostial, Ostiate, Ostiolar Peritreme, Ostiolate, Ostiole, Ostiola, Ostium, Ostium Bursae, Ostium Oviductus, Ostracoda, Ostracum, Ostreiidae, Ostreina, Otidium, Otiorrhynchinae, Otitidae (Ulidiidae), Otocrypt, Otocyst, Otolith, Otoporpae, Otu, Out Breeding, Outbreak Area, Outer Coelomic Space, Outer Face, Outer Leaf Crown, Outer Ligament, Outer Lip, Outer Pigment Cells, Outer Plate, Outer Squama, Outer Vertical Bristles, Ova, Ovarial Ligament, Ovarian Balls (Free Floating Ovaries), Ovarian Lamellae, Ovarian Tube, Ovariectomy, Ovariicolous, Ovarioles (Ovarian Tubules), Ovariotestes, Ovary (Oarium, Ovarium), Ovate, Ovately-Conic, Ovate-Oblong, Ovate-Subquadrate, Ovenchyma, Over Specialization, Overcrowding Effect, Overdispersion, Overdominance (Superdominance), Ovicapsule, Ovicapt, Ovicell, Ovicentre, Ovicide, Oviducal Gland, Oviducal, Oviduct, Oviferous (Ovigerous), Oviform, Oviger, Ovigerous, Ovigerous Frenum, Ovigerous Lamella, Ovijector (erron. Ovejector), Oviparous (Ovipary), Oviporous, Oviposit, Oviposition, Ovipositor (Oviscapte), Ovisac, Oviscapte, Ovisorption, Ovivalvula, Ovocyst, Ovocyte, Ovogenesis, Ovoglobulin, Ovoid, Ovoplasm, Ovotestis, Ovovitellarium, Ovoviviparous, Ovulate (Ovulation), Ovum, Oweniidae, Oweniimorpha, Owlflies, Oxaeidae, Oxea, Oxeote, Oxyaster, Oxybiotic, Oxychlorocuorin, Oxycorynidae, Oxydactylous, Oxydiact, Oxyerythrocruorin, Oxygen Isotope Ratio, Oxygenotaxis (Oxytaxis), Oxygnathous, Oxyhaemocyanin, Oxyhaemoerythrin, Oxyhaemoglobin (HBO2), Oxyhexactine, Oxyhexaster, Oxyluciferin, Oxynitic Cells, Oxyntic Cells (Parietal Cells), Oxyopidae, Oxyphilic, Oxyphobe, Oxyphobic, Oxyrhyncha, Oxystomata, Oxytropism, Oxytylote, Oxyuroidea, Oyster Crab, Oyster, Ozadene, Ozopore.