Marine Invertebrates
A collection of all the species I have seen from the coasts of California to Washington to Hawaii.
This page will be continuously updated as I continue encountering new species & taking photos of old friends.
For more check out my photography account on Instagram or my account on Bluesky.
Updated 4.1.25
Segmented Worms
3/15,000+ Species
Phylum: Annelida
California Sandcastle Worm // Phragmatopoma californica
Red-trumpet Calcareous Tubeworm // Serpula columbiana
California Christmas Tree Worm // Spirobranchus spinosus
Crustaceans
30/67,000+ Species
Phylum: Arthropoda
Subphylum: Crustacea
Left-handed Hermit Crab // Calcinus laevimanus
Seurat's Hermit Crab // Calcinus seurati
Red Rock Crab // Cancer productus
Ninetooth Pebble Crab // Cycloxanthops novemdentatus
Pacific Sand Crab // Emerita analoga -- Photo Credit: Nate K.
Purple Shore Crab // Hemigrapsus nudus
Yellow Shore Crab // Hemigrapsus oregonensis -- Photo Credit: Nate K.
Mexican Fiddler Crab // Leptuca crenulata
Western Sea Slater // Ligia occidentalis
Red Rock Shrimp // Lysmata californica
Yellow Rock Crab // Metacarcinus anthonyi
Graceful Rock Crab // Metacarcinus gracilis
Striped Shore Crab // Pachygrapsus crassipes
Pleated Rock Crab // Pachygrapsus plicatus
Pacific Hairy Hermit Crab // Pagurus hirsutiusculus
Blueband Hermit Crab // Pagurus samuelis
Ventura Hermit Crab // Pagurus venturensis
California Spiny Lobster // Panulirus interruptus
Red-striped Acorn Barnacle // Paraconcavus pacificus
Eelgrass Isopod // Pentidotea resecata
Rockweed Isopod // Pentidotea wosnesenskii
Cabrillo Porcelain Crab // Petrolisthes cabrilloi
Flat Porcelain Crab // Petrolisthes cinctipes -- Photo Credit: Yueqi W.
Gooseneck Barnacle // Pollicipes polymerus
Northern Kelp Crab // Pugettia producta
Northern Kelp Crab Eggs // Pugettia producta
Pacific Rock Crab // Romaleon antennarium
Southern Kelp Crab // Taliepus nuttallii
Pink Volcano Barnacle // Tetraclita rubescens
Large Mexican Fiddler Crab // Uca princeps
Bryozoan
1/5,000+ Species
Phylum: Bryozoa
Sargassum Sea Mat // Jellyella tuberculata
Cnidarians
17/10,000+ Species
Phylum: Cnidaria
*** Not pictured is the Purple-striped Sea Nettle // Chrysaora colorata
Moonglow Anemone // Anthopleura artemisia
Aggregating Anemone // Anthopleua elegantissima
Anthopleura mariae
Sunburst Anemone // Anthopleura sola
Giant Green Anemone // Anthopleura xanthogrammica
Aggregating Cup Coral // Astrangia haimei
Warty Columned Anemone // Aulactinia incubans
Orange Cup Coral // Balanophyllia elegans
Californian Strawberry Anemone // Corynactis californica
Brooding Anemone // Epiactis prolifera
Ten-tentacled Burrowing Anemone // Halcampa decemtentaculata
Red-eye Medusa // Polyorchis penicillatus
Blue Button // Porpita porpita
Pacific Stubby Rose Anemone // Urticina clandestina
Painted Anemone // Urticina grebelnyi
By-the-wind Sailor // Velella velella
echinoderms
14/7,000+ Species (not including Asteroidea)
Phylum: Echinodermata
Dwarf Brittle Star // Amphipholis squamata
Warty Sea Cucumber // Apostichopus parvimensis
Shingle Urchin // Colobocentrotus atratus
Orange Sea Cucumber // Cucumaria miniata
Eccentric Sand Dollar // Dendraster excentricus
Indo-Pacific Rock-boring Urchin // Echinometra mathaei
Oblong Sea Urchin // Echinometra oblonga
Red Sea Urchin // Mesocentrotus franciscanus
Panama Serpent Star // Ophioderma panamense
Banded Brittle Star // Ophionereis annulata
Ophionereis diabloensis
Rough Banded Brittle Star // Ophiothrix rudis
Western Spiny Brittle Star // Ophiothrix spiculata
Pacific Purple Sea Urchin // Strongylocentrotus purpuratus
Sea Stars
8/~2,000 Species
Phylum: Echinodermata
Subphylum: Asterozoa
Class: Asteroidea
Fragile Rainbow Star // Astrometis sertulifera
Leather Star // Dermasterias imbricata
Mottled Star // Evasterias troschelii
Dwarf Mottled Henricia // Henricia pumila
Bat Star // Patiria miniata
Giant Pink Sea Star // Pisaster brevispinus
Giant Sea Star // Pisaster giganteus
Ochre Sea Star // Pisaster ochraceus
Molluscs
48/76,000+ Species (terrestrial & marine; not including Sacoglossa & Nudibranchia)
Phylum: Mollusca
*** Not included is the File Limpet // Lottia limatula & the Merten’s Chiton // Lepidozona mertensii
Angular Unicorn // Acanthinucella spirata
Carinate Dovesnail // Alia carinata
California Seahare // Aplysia californica
Black Seahare // Aplysia vaccaria
Engel's Gumdrop // Berthellina ilisima -- Photo Credit: Miguel H.
Cloudy Bubble Snail // Bulla gouldiana
Fat Nassa // Caesia perpinguis
Purple Olive Snail // Callianax biplicata
Giant Rock Scallop // Crassadoma gigantea
Gumboot Chiton // Cryptochiton stelleri
Hartweg's Chiton // Cyanoplax hartwegii
Rough Keyhole Limpet // Diodora aspera
Seaweed Limpet // Discurria insessa
Volcano Keyhole Limpet // Fissurella volcano
Green Abalone // Haliotis fulgens
Green Bubble Snail // Haminoea virescens
Pink Bubble Snail // Hydatina amplustre
Black Leather Chiton // Katharina tunicata
Kellet's Whelk // Kelletia kelletii
Cooper's Chiton // Lepidozona cooperi -- Photo Credit: Nate K.
Kelp Scallop // Leptopecten latiauratus
Owl Limpet // Lottia gigantea
Rough Limpet // Lottia scabra -- Photo Credit: Nate K.
Giant Keyhole Limpet // Megathura crenulata
Wavy Turban // Megastraea undosa
Dark Unicorn // Mexacanthina lugubris
Woody Chiton // Mopalia lignosa
Mossy Chiton // Mopalia muscosa
California Mussel // Mytilus californianus
California Aglaja // Navanax inermis
Chestnut Cowry // Neobernaya spadicea
Norris's Topsnail // Norrisia norrisii
California Spiny Chiton // Nuttallina californica
Scale-sided Piddock // Parapholas californica
Festive Murex // Pteropurpura festiva
Solander's Trivia // Pusula solandri
Conspicuous Chiton // Stenoplax conspicua
Surfgrass Limpet // Tectura paleacea
Black Tegula // Tegula funebralis
Speckled Tegula // Tegula gallina
Scaled Worm Snail // Thylacodes squamigerus
Lined Chiton // Tonicella lineata
Yellow Umbrella Slug // Tylodina fungina
Lesser Two-spot Octopus // Octopus bimaculoides
California Marginella // Volvarina taeniolata
Sapsuckers
2/~284 Species
Phylum: Mollusca
Class: Gastropoda
Superorder: Sacoglossa
Entermorpha-eating Sapsucker // Aplysiopsis enteromorphae
Hedgpeth's Sapsucker // Elysia hedgpethi
Nudibranchs
46/~3,000 Species
Phylum: Mollusca
Class: Gastropoda
Order: Nudibranchia
Nanaimo Dorid // Acanthodoris nanaimoensis
Black and White Dorid // Acanthodoris rhodoceras
Salt-and-pepper Doris // Aegires albopunctatus
Warty Shag-rug Nudibranch // Aeolidia loui
Ancula pacifica
Colorful Aeolid // Anteaeolidiella chromosoma
Olive's Aeolid // Anteaeolidiella oliviae
Cockscomb Nudibranch // Antiopella barbarensis
White-and-orange-tipped Nudibranch // Antiopella fusca
Stearn's Aeolid // Austraeolis stearnsi
Baba's Festive Aeolid // Babakina festiva
Mimic Dorid // Baptodoris mimetica
Yellow-spotted Cadlina // Cadlina flavomaculata
Dark-spot Cadlina // Cadlina sparsa
British Columbia Aeolid // Catriona columbiana
Hopkin's Rose // Ceratodoris rosacea
Pacific Corambe // Corambe pacifica
Cooper's Aeolid // Coryphella cooperi
Three-lined Aeolid // Coryphella trilineata
Rabbit Dorid // Crimora coneja
Rose-pink Cuthona // Cuthona divae
Chocolate Aeolid // Cuthonella cocoachroma
Stubby Dendronotid // Dendronotus subramosus
Branched Dendronotid // Dendronotus venustus
Northern Leopard Dorid // Diaulula odonoghuei
San Diego Dorid // Diaulula sandiegensis
White-spotted Sea Goddess // Doriopsilla albopunctata
Yellow-gilled Sea Goddess // Doriopsilla gemela
Doriopsilla rowena
Monterey Dorid // Doris montereyensis
Doto urak
California Chromodorid // Felimare californiensis
Spanish Shawl // Flabellinopsis iodinea
Heath's Dorid // Geitodoris heathi
Horned Nudibranch // Hermissenda crassicornis
Opalescent Nudibranch // Hermissenda opalescens
Opalescent Nudibranch Eggs // Hermissenda opalescens
Cockerell's Dorid // Limacia cockerelli
McDonald's Dorid // Limacia mcdonaldi
Noble Dorid // Peltodoris nobilis
Two-spotted Dorid // Thordisa bimaculata
White Crusted Aeolid // Trinchesia albocrusta
Clown Dorid // Triopha catalinae
Spotted Dorid // Triopha maculata
Festive Tritonid // Tritonia festiva
Red Sponge Dorid // Rostanga pulchra
Ribbon Worms
1/1,300+ Species
Phylum: Nemertea
Tubulanus ruber
Flatworms
1/20,000 Species
Phylum: Platyhelminthes
Enchiridium punctatum
Sponges
1/5,000 Species
Phylum: Porifera
Aiolochroia thiona
Tunicates
7/3,000+ Species
Phylum: Chordata
Subphylum: Tunicata
Pacific Sea Pork // Aplidium californicum
Chain Tunicate // Botrylloides violaceus
Ciona savignyi
Mushroom Tunicate // Distaplia occidentalis
Fused Orange Social Ascidian // Metandrocarpa dura
Taylor's Social Tunicate // Metandrocarpa taylori
Pleated Sea Squirt // Styela plicata