Classification of Marine Organisms (1/3)
Here is an abbreviated classification or taxonomy of all the organisms presented in this website, as well as a few others of interest. This is not meant to be a complete listing of all living things, nor even a completely correct one, since these classifications change as new theories come into favor. One should realize that every one of the groupings presented below is a judgment call representing collective scientific opinion, rather than a hard fact.
The classification of living things into groups depends not only on their differences and similarities but also on the degree to which they are studied and understood. For example, lesser-studied types such as mollusks tend to be lumped together into broad classifications, while popular and easily-studied types tend to be divided into fine distinctions. For a prime example of this, pick up any field guide on birds, and see how many Warblers there are in it. Birds are widely considered to be "over-split" - divided into many different species and families that are really not different. Coincidentally, bird-watching is an extremely popular pastime among scientists and laymen alike. Conversely, mollusks are probably "under-split", but then mollusk-watching is no fun at all.
As you move to the right in this outline, the groupings become progressively more specific. In addition, there is a great deal more detail in some areas than others. It would be incorrect to infer from this that one group, say fishes, is much more diverse than another, say insects. Insects are the most numerous creatures on earth in terms of species, but here they occupy only 8 lines, because they are of little interest to scuba divers in the North Atlantic, while fish, on the other hand, occupy fully half of the listing. See below for further explanations of the system of taxonomic classification.
Minerals - nonliving material - coast, bottom, water, weather, pollution
Viruses - there is no general agreement as to whether or not viruses qualify as living
Kingdom Monera - bacteria - single-celled / colonial, no cell nuclei
- Eubacteria - "new" or modern bacteria
- Cyanobacteria - Blue-Green Algae - photosynthetic
Kingdom Protista - single- and multi- cellular organisms, cells with nuclei
- Phylum Rhizopoda - amoebas - animal-like, mobile
- Phylum Ciliophora - parameciums - animal-like, mobile
- Phylum Dinoflagellata - dinoflagellates - both animal and plant-like, mobile
- Phylum Euglenophyta - euglenoids - both animal and plant-like, photosynthetic, mobile
- Phylum Chrysophyta - yellow algae & diatoms - plant-like, photosynthetic
- Phylum Phaetophyta - Brown Algae, kelps, Sargassum - plant-like, photosynthetic
- Phylum Chlorophyta - Green Algae - plant-like, photosynthetic
- Phylum Rhodophyta - Red Algae - plant-like, photosynthetic
- Phylum Myxomycota - slime molds - fungus-like
Kingdom Plantae - true plants - multicellular, distinct roots, stems & leaves, photosynthetic
- Division Bryophyta - mosses - very simple seedless plants
- Division Pterophyta - ferns - higher seedless plants
- Division Coniferphyta - conifers - non-flowering seed plants ( pines, etc )
- Division Spermatophyta - flowering plants
- - Class Monocotyledones - Grasses, Water-Weeds, and most non-woody plants
- - Class Dicotyledones - most trees and woody plants
Kingdom Fungi - mushrooms, molds, etc, multicellular, non-photosynthetic
Kingdom Animalia ( Metazoa ) - multicellular, mobile, non-photosynthetic
- Phylum Porifera - Sponges - no true organs or tissues, digestive system, sexes
- Phylum Cnidaria - radially symmetric, stingers, simple nerve net, separate sexes
- - Class Hydrozoa - Hydroids, Hydromedusae, Man'O'War
- - Class Scyphozoa - Jellyfishes - mobile medusa stage predominant
- - Class Anthozoa - sessile polyp stage predominant, medusa almost absent
- - - Sub-Class Actineria - Sea Anemones - soft-bodied polyps
- - - Sub-Class Octocorallia - soft corals - Sea Pens, Sea Whips
- - -Sub-Class Schleractinia - hard corals - mainly tropical
- Phylum Ctenophora - Comb Jellies - bilaterally symmetric, biolumenescent, cilia
- Phylum Bryozoa - "Moss Animals" - very common, no clear relationship to other groups
- Phylum Rotifera - rotifers - microscopic freshwater "wheel animals"
- Phylum Platyhelminthes - flatworms, tapeworms, flukes - no circulatory system
- Phylum Nematoda - roundworms - no circulatory system
- Phylum Nemertina - proboscis worms - heartless circulatory system
- Phylum Annelida - segmented worms - fully developed body cavity & heart
- - Class Oligochaeta - earthworms - mostly terrestrial, some aquatic and/or marine
- - Class Polychaeta - Clam Worms, Fan Worms - marine
- - Class Hirudinea - leeches - parasitic / predatory, freshwater only
- Phylum Mollusca - mollusks - hard calcareous external shells
- - Class Polyplacophora - chitons - primitive 8-segment shell
- - Class Gastropoda - single conical or coiled shell or shell-less
- - - Sub-Class Prosobranchia - marine snails, Slipper Shells, limpets - no operculum
- - - Sub-Class Pulmonata - freshwater & land snails - operculum, lungs
- - - Sub-Class Opisthobranchia - sea slugs, nudibranchs, sea butterflies
- - Class Bivalvia - 2-part shell, filter-feeders
- - - Sub-Class Pteriomorpha - Mussels, Oysters, Scallops
- - - Sub-Class Heterodonta - Clams, Teredos, Zebra Mussels
- - Class Cephalopoda - Squids, octopus - reduced shell, intelligent, carnivorous
- Phylum Chelicerata - no antennae or jaws
- - Class Arachnida - spiders, ticks, scorpions - book lungs
- - Class Merostomata - Horseshoe Crab - book gills
- Phylum Arthropoda - hard calcareous exoskeleton, jointed legs
- - Class Insecta - insects - no true lungs, gills, claws, single pair of antennae, terrestrial
- - - Order Coleoptera - beetles - fore-wings hardened into wing covers, grub-like larvae
- - - Order Diptera - true flies, mosquitos - two wings, grub-like larvae
- - - Order Hemiptera - true bugs, larvae resemble adults, generally soft-bodied
- - - Order Odonata - dragonflies & damselflies - four wings beat in opposite pairs
- - - Order Plecoptera - stoneflies - aquatic larvae
- - - Order Trichoptera - caddisflies - aquatic larvae
There are 29 Orders of insects. Only those that are aquatic are listed here.
- - Class Crustacea - clawed appendages, two pairs of antennae, gills
- - - Sub-Class Branchiopoda - Water Fleas, Tadpole Shrimps
- - - Sub-Class Cirripedia - Barnacles, Goose Barnacles
- - - Sub-Class Copepoda - copepods, fish lice, Ribbon Lice
- - - Sub-Class Amphipoda - Gammarus, Skeleton Shrimp
- - - Sub-Class Malacostraca - higher crustaceans
- - - - Order Isopoda - Isopods - flattened
- - - - Order Decapoda - "10 leggers"
- - - - - Infra-Order Palinura - spiny lobsters - no claws at all, antennae used as pokers
- - - - - Infra-Order Caridea - Shrimps - no large claws
- - - - - Infra-Order Astacidea - Lobsters, Crayfish - 3 sets of claws, first set large
- - - - - Infra-Order Anomura - Hermit Crabs, Mole Crabs - intermediate types
- - - - - Infra-Order Brachyura - true crabs - 1 set of claws, greatly reduced tail
- - - - Order Stromatopoda - Mantis Shrimps - 8 pairs of legs
- Phylum Echinodermata - 5-way body symmetry, water vascular system, tube feet
- - Class Asteroidea - Sea Stars ( Starfish ) - 5 or more arms
- - Class Ophiuroidea - Brittle Stars - more delicate in appearance and construction
- - Class Echinoidea - Sea Urchins & Sand Dollars - hard external skeleton, no arms
- - Class Crinoidea - sea lilies - sessile upside-down starfish, declining as a group
- - Class Holothuridea - Sea Cucumbers - wormlike, leathery skins
- Phylum Chordata - hollow dorsal nerve cord (notochord), post-anal tail
- - Sub-Phylum Urochordata - Sea Squirts & tunicates - notochord only in mobile larvae
--Sub-Phylum Vertebrata - flexible internal skeleton, brain encased in cranium
- - - Class Agnatha - lampreys & hagfishes - cartaliginous skeleton, no paired fins or jaws
- - - Class Chondrichthyes - cartaliginous fishes - true jaws & teeth, cartiliginous skeleton
- - - - Sub-Class Holocephalii - Rabbitfishes, Chimeras - fixed upper jaw
- - - - Sub-Class Elasmobranchii - both jaws movable, ~800 species
- - - - - Super-Order Squatinomorphi - 6-gill sharks - primitive deepwater sharks
- - - - - Super-Order Galeomorphi - 5-gill sharks - dominant group - 75% of all sharks
- - - - - - Order Lamniformes - typical sharks
- - - - - - - Family Alopidae - Thresher Sharks
- - - - - - - Family Lamnidae - "Mackerel Sharks" - Great White, Mako, Basking, Porbeagle
- - - - - - - Family Carcharhinidae - "Requiem Sharks" - Tiger, Bull, Blue, Smooth Dogfish
- - - - - - - Family Odontaspididae - Sand Tiger
- - - - - - - Family Orectolobidae - Nurse Sharks
- - - - - - - Family Rhincodontidae - Whale Shark
- - - - - - - Family Scyliorhinidae - "Cat Sharks" - Chain Dogfish
- - - - - - - Family Sphyrnidae - Hammerhead Sharks
- - - - - - Order Sqaliformes - Spiny Dogfishes, Angel Sharks
- - - - - Super-Order Batoidea - skates, rays, sawfishes, guitarfish
- - - - - - Order Rajiformes - bottom-dwelling shellfish eaters
- - - - - - - Family Dasyatidae - Stringrays
- - - - - - - Family Myliobatidae - Rays
- - - - - - - Family Rajidae - Skates
- - - - - - - Family Torpedinidae - Electric Rays
- - - - - - - Family Mobulidae - manta rays - filter-feeders
- - - Class Osteichthyes - bony fishes - true jaws & teeth, skeleton, swim bladder
-- Sub-Class Sarcopterygii - lungfishes, coelocanth
-- Sub-Class Actinopterygii - ray fins
- - - Infra-Class Chondrostei - sturgeons & paddlefishes - ~25 species
- - - Infra-Class Neopterygii - "modern" fishes
- - - - Division Holostei - gars, bowfin - short grasping jaws, lungs, ~25species
- - - - Division Teleostei - extensible mouths, flexible fins, ctenoid scales, ~17k species
- - - - - Cohort Taenipaedia - leptocephalous ( "leaf-like" ) larva
- - - - - - Order Anguilliformes - eels
- - - - - - - Family Anguillidae - freshwater eels - American Eel - paired pectoral fins
- - - - - - - Family Congridae - saltwater eels - Conger Eel - paired pectoral fins
- - - - - - - Family Muraenidae - moray eels - no paired fins
- - - - - - Order Elopiformes - tarpons & bonefishes ( classification debatable )
- - - - - Cohort Clupeocephala - swim bladder connected to skull to improve hearing
- - - - - - Order Clupeiformes - salt and fresh-water plankton feeders
- - - - - - - Family Clupeidae - Herrings, Shad, Sardines - short protruding lower jaw
- - - - - - - Family Engraulidae - Anchovies - long overhanging snout
- - - - - Cohort Euteleostei - "true teleosts"
- - - - - - Super-Order Protoacanthopterygii - not-quite-modern fishes
- - - - - - - Order Esociformes - Pikes, Mudminnows
- - - - - - - Order Salmoniformes - Trouts, Salmons, Smelts
- - - - - - Super-Order Ostariophysi - dominant freshwater group
- - - - - - - Order Cypriniformes - toothless jaws, teeth in throat, ~2500 species
- - - - - - - - Family Catostomidae - Suckers
- - - - - - - - Family Cyprinidae - Minnows, Carps, Goldfish
- - - - - - - Order Characiformes - "tetras" - popular aquarium fishes
- - - - - - - Order Siluriformes - catfishes
- - - - - - Super-Order Paracanthopterygii - spineless fins
- - - - - - - Order Batrachoidiformes - Toadfishes
- - - - - - - Order Gadiformes - Cods, Hakes, Cusks, Burbot
- - - - - - - Order Ophidiformes - Cusk Eels
- - - - - - - Order Lophiiformes - Goosefish, Sargassumfish
- - - - - - Super-Order Scopelomorpha
- - - - - - - Order Aulopiformes - Inshore Lizardfish, deep-sea gulpers
- - - - - - Super-Order Acanthopterygii - spiny rayed fishes, ~10,000species
- - - - - - - Atheriniformes -Silversides
- - - - - - - Cyprinodontiformes - Killyfish, Needlefish, livebearers, flying fishes
- - - - - - - Gasterostiformes
- - - - - - - - Family Gasterostidae - Sticklebacks
- - - - - - - - Family Syngnathidae - Pipefishes, Seahorses - pipe-like suctioning mouths
- - - - - - - Pleuronectiformes - flatfish
- - - - - - - - Family Bothidae - lefteye flounders
- - - - - - - - Family Pleuronectidae - righteye flounders
- - - - - - - - Family Soleidae - Soles
- - - - - - - Order Scorpaeniformes - ~1100species
- - - - - - - - Family Cottidae - Sculpins - mostly freshwater
- - - - - - - - Family Scorpaenidae - Sea Ravens, Lionfish, Rockfishes, Scorpionfishes
- - - - - - - - Family Triglidae - Sea Robins, Gurnards
- - - - - - - Order Tetraodontiformes - teeth fused into bony chisels, tough leathery skin
- - - - - - - - Family Diodontidae - Burrfishes - large spines, "2-teeth"
- - - - - - - - Family Tetraodontidae - Puffers - small spines, "4-teeth"
- - - - - - - - Family Balistidae - Triggerfishes, Filefishes
- - - - - - - - Family Ostraciidae - Trunkfishes
- - - - - - - - Family Molidae - Molas ( Ocean Sunfish )
- - - - - - - Order Perciformes - perch-like fishes, "ruling perches", ~ 7000 species
- - - - - - - - Family Ammodytidae - Sand Lances
- - - - - - - - Family Blenniidae - Blennies
- - - - - - - - Family Carangidae - Jacks, Scads, Rudderfish
- - - - - - - - Family Centrarchidae - freshwater Sunfish & Basses ( N. America only )
- - - - - - - - Family Chaetodontidae - Butterflyfishes
- - - - - - - - Family Cichlidae - cichlids - popular aquarium fishes
- - - - - - - - Family Ephippidae - Spadefish
- - - - - - - - Family Gobiidae - Gobies
- - - - - - - - Family Holocentridae - Squirrelfishes
- - - - - - - - Family Labridae - wrasses - Blackfish, Cunner, tropical parrotfishes
- - - - - - - - Family Malacanthidae - Tilefish
- - - - - - - - Family Mugiloidae - Mullets, Barracudas
- - - - - - - - Family Percicthyidae - Striped Bass, WhitePerch - temperate basses
- - - - - - - - Family Percidae - Darters, Walleye, "true perches" - freshwater
- - - - - - - - Family Pomatomidae - Bluefish
- - - - - - - - Family Scianidae - Drums, Kingfishes, Spot
- - - - - - - - Family Scombbroidei - Mackerels, Tunas, billfishes
- - - - - - - - Family Serranidae - Black Sea Bass, Scamp - sea basses
- - - - - - - - Family Sparidae - Porgies, Scup, Sheepshead
- - - - - - - - Family Uranoscopidae - Stargazers
- - - - - - - - Family Xiphiidae - Swordfish
- - - - - - - - Family Zoarcidae - Eelpouts, Gunnels
There are many, many more families in this order.
- - - Class Amphibia - cold-blooded tetrapods, egg-laying, partially terrestrial
- - - Order Anura - frogs, toads - tailless
- - - Order Caudata - salamanders, newts, sirens
- - - Class Reptilia - cold-blooded tetrapods, egg-laying, fully terrestrial
- - - - Order Crocodylia - crocodiles, alligators, caimans, etc
- - - - Order Squamata - lizards, snakes
- - - - Order Testudines - turtles, sea turtles
- - - Class Aves - birds - warm-blooded egg-laying flight-adapted tetrapods with feathers
- - - - Order Anseriformes - waterfowl - ducks, geese
- - - - Order Apodeformes - swifts, hummingbirds
- - - - Order Charadriiformes - gulls, terns, sandpipers, plovers
- - - - Order Ciconiiformes - herons, bitterns
- - - - Order Falconiformes - hawks, eagles, vultures, osprey
- - - - Order Pelecaniformes - pelicans, cormorants, gannets, boobies
- - - Class Mammalia - mammals - warm-blooded tetrapods with hair and mammary glands
- - - - Order Carnivora - carnivores - canines, felines, bears, raccoons, weasels, seals
- - - - Order Cetacea - whales, dolphins, porpoises
- - - - Order Primates - monkeys, apes, humans
- - - - Order Rodentia - rodents - rats, mice, muskrat, beaver
- - - - Order Sirenia - manatees, dugongs