Zooplankton of Southern California

Photographed and compiled by Peter J. Bryant (pjbryant@uci.edu)
Department of Developmental and Cell Biology, University of California, Irvine, CA 92697



Parafavella sp.

Stalked Ciliate,
Peritricha sp.


Bell Tintinnid,
Tintinnopsis (campanula?)

Vorticella sp.

Globigerina sp.



Diploconus sp.

Acantharia sp.

Unidentified 1

Unidentified 2
Rotifers Sponges Bryozoa  


Parenchymella larva

Coronate larva

Cyphonautes larva
Class Hydrozoa: Order Anthomedusae
Bougainvilliidae Cladonematidae Corymorphidae Polyorchidae  

Bougainvillia sp.

Cladonema (californicum?)

Corymorpha bigelowi

Giant Bell Jelly,
Scrippsia pacifica
Order Leptomedusae
Aequoreidae  Campanulariidae

Crystal Jelly, Aequorea victoria

Clytia elsaeoswaldae

Clytia gracilis

Clytia sp.

Obelia sp.
Order Siphonophorae   Order Narcomedusae Order Trachymedusae
Diphyidae Physonectae   Solmarisidae Geryoniidae

Lensia campanella

Nanomia sp. (larva)
Unidentified Narcomedusa

Liriope tetraphylla
Class Anthozoa Class Scyphozoa  


Arachnactidae Pelagiidae Ulmaridae

Onion anemone,
Paranthus rapiformis

Tube-dwelling anemone, Isarachnanthus nocturnus (Cerinula larva)
Black Sea Nettle (Black Jellyfish), Chrysaora achlyos
West Coast Sea Nettle,
Chrysaora fuscescens

Moon Jelly,
Aurelia aurita
Platyhelminths   Ctenophores    

Trematode (Cercaria Larva)
Sea gooseberry,
Pleurobrachia bachei
Oweniidae Polynoidae (Scale Worms) Sternaspidae Syllidae  

Owenia sp. (larva)

Unidentified larva

Sternaspis sp.

Odontosyllis phosphorea
Unidentified Polychaete Larvae

Unidentified polychaete larva #1

Unidentified polychaete larva #2

Unidentified polychaete larva #3

Unidentified polychaete larva A3

Unidentified polychaete larva A4
Limapontiidae Atlantidae (Sea Snails) Desmopteridae    

Brown-streak Stiliger,
Stiliger fuscovittatus

Sea Snail,
Atlanta (californiensis?)

Sea Butterfly,
Desmopterus pacificus
Mollusk larvae

Veliger larva

Veliger larva

Limpet Veliger

Bivalve larvae  

Amphithoe plumulosa

Skeleton Shrimp, Caprella mendax

Elasmopus bampo

Jassa slatteryi

Zeuxo sp.

Hyalid amphipod
Cirripedia (Barnacles)

Goose Barnacle,
Pollicipes polymerus

Ivory Barnacle,
Amphibalanus eburneus
Cladocera The Cladocerans

Marine Cladoceran,
Evadne sp.

Marine Cladoceran,
Penilia avirostris

Marine Cladoceran, Pleopis polyphemoides

Marine Cladoceran,
Pseudevadne tergestina

Calanoid Copepod,
Acartia sp.

Calanus pacificus

Sea Louse,
Caligus sp.

Caligoid (parasitic) copepod
(Sea Louse)

Mecynocera clausi

Paracalanus parvus

Calanoid copepod

Cyclopoid Copepod

Cyclopoid Copepod

Harpacticoid Copepod

Nauplius II larva

Marine Isopods Guide to the Coastal Marine Isopods of California

Water slater,
Asellus aquaticus

Marine isopod, Cilicaea sp.

Harford's Isopod,
Cirolana harfordi

Elthusa californica

Excirolana chiltoni

Bigtail Isopod,
Exosphaeroma amplicauda

Exosphaeroma inornata
Paranthura elegans

Marine Isopod, Zeuxo sp.

Marine Isopod

Marine Isopod

Mysidacea Ostracods      

Opossum Shrimp

Decapods (Shrimp, crayfish, lobsters, crabs)
Palinuridae Grapsidae Pinnotheridae  

California Spiny Lobster,
Panulirus interruptus, larva

Striped shore crab,
Pachygrapsus crassipes, zoea larva

Striped shore crab,
Pachygrapsus crassipes, megalops larva

Pea crab,
Pinnixa franciscana, zoea larva

Porcellanidae: Porcelain Crabs Portunidae Varunidae  

Zoea Larva

Zoea Larva

Swimming Crab,
Portunus xantusii, megalops larva

Yellow Shore Crab,
Hemigrapsus oregonensis

A collection of unidentied megalops larvae

Rosy Bryozoan, Integripelta bilabiata, Coronate larva

Cyphonautes larva (unidentified)

Larva of unidentified Brittle Star

Brachiolaria larva of unidentified Sea Star

Juvenile Sea Star
Class: Appendicularia (Larvaceans), Family Fritillariidae  Class: Appendicularia (Larvaceans), Family Oikopleuridae    

Fritillaria borealis

Oikopleura sp.
Class Thaliacea (Salps)  

Pyrosoma sp.

Cyclosalpa affinis

Salpa fusiformis

Thalia rhomboides


Zooplankton analysis by microscopy and molecular biology
Research in the laboratory of Dr. Peter J. Bryant, Department of Developmental and Cell Biology, University of California, Irvine


Zooplankton (see the figure below) refers to the astonishing diversity of small animals that drift in the ocean, where they serve as the main consumers of phytoplankton as well as the main food source for a variety of secondary consumers including fish and whales. Zooplankton includes copepods, the most abundant metazoan taxon on earth. Studies of zooplankton provide a convenient and inexpensive method of marine habitat monitoring, giving an indication of the health of the phytoplankton population upon which these animals feed, as well as an indication of the levels of food availability for carnivorous animals higher in the food chain.

Some of the organisms in zooplankton (e.g. copepods) spend their entire life cycle in the water column, whereas others spend only the larval stages as plankton and then settle to the seabed, intertidal areas or other solid substrates for their adult stages. The larval stages show many important adaptations to pelagic life including filter-feeding mechanisms and appendages for maintaining position in the water column. The adaptations make the larval stages so different from the adults that special mechanisms of metamorphosis have evolved to allow the change from larva to adult (Hall and Wake, 1999; Hickman, 1999). This means that it is difficult to match larvae with corresponding adult stages by morphological analysis. However, species-specific DNA sequences can be used to make these correlations. We are exploring the diversity and abundance of zooplankton in Newport Bay, California, as well as the nearby Pacific Ocean, paying attention to geographic distribution as well as seasonality of the populations. We collect samples of zooplankton by pulling a net with a 150um mesh through a vertical or horizontal column of water. Individuals of each morphologically identifiable type are selected from each sample and recorded by photo- and video-microscopy, then preserved in ethanol for sequencing of the segment of mitochondrial DNA called the DNA Barcode. The samples are sent to the Barcode of Life (BOLD) consortium at the University of Guelph, Ontario, Canada for DNA sequencing.

DNA barcoding allows us to match up larval stages with the corresponding adults, which previously could be done only by the laborious rearing of individual larvae. DNA barcodes for many of the species we are studying have already been determined and made available by BOLD, so it is not always necessary to determine DNA barcodes for adults. The work includes all invertebrates that have pelagic stages of the life cycle, including crustaceans, annelids, mollusks, cnidarians, echinoderms and bryozoans.

Students will learn about techniques used in photomicroscopy and videomicroscopy by investigating zooplankton collected from various sites around Upper and Lower Newport Bay as well as from the open ocean. The project affords an excellent opportunity for students to learn many aspects of zoology and ecology that are not available through traditional classroom and laboratory work.

The work is covered by a Scientific Collecting Permit from the California Department of Fish and Wildlife.


Barcode of Life: Identifying Species with DNA Barcoding. http://www.barcodeoflife.org/content/about/what-dna-barcoding. Accessed 11/4/2013

Hall, B. K. and Wake, M. V. (1999). Introduction: Larval Development, Evolution, and Ecology. pp 1-19 in: Hall, B. K. and Wake, M. V. (1999). The Origin and Evolution of Larval Forms. Academic Press, San Diego. 1999. 425 pp.

Hickman, C. S. (1999). Larvae in Invertebrate Development and Evolution. pp 21-59 in: Hall, B. K. and Wake, M. V. (1999). The Origin and Evolution of Larval Forms. Academic Press, San Diego. 1999. 425 pp.

Perry, R. (2003). A Guide to the Marine Plankton of Southern California. http://www.msc.ucla.edu/oceanglobe/pdf/guide_plankton1.pdf. Accessed 11/4/2013.

Young, C.M., Rice, M.E., and Sewell, M.A. (2002). Atlas of Marine Invertebrate Larvae. Academic Press, New York. 626 pp.

1: Polychaete larva; 2: Juvenile sea urchin; 3: Veliger larva of gastropod; 4: Actinotroch larva of a phoronid worm; 5: Female calanoid copepod with egg sacs; 6: Juvenile sea urchin; 7: Copepodite larva of copepod; 8: Medusa of Cladonema; 9: Ophiopluteus larva of a brittle star; 10: Polychaete larva; 11: Juvenile sea urchin; 12: Veliger larva of slipper limpet; 13: Foraminiferan, Globigerina; 14: Moustache worm; 15: Rotifer; 16: Cumacean; 17: Skeleton of foraminiferan, Globigerina; 18: Cyphonautes larva of a bryozoan; 19: Stalked ciliate, Peritricha sp.; 20: Cyclopoid copepod; 21: Harpacticoid copepod; 22: Nauplius larva of copepod; 23: Ophiopluteus larva of a brittle star; 24: Polychaete; 25: Medusa of Obelia; 26: Zoea larva of crab; 27: Muller's larva of a flatworm; 28: Cubomedusa; 29: Cerinula larva of sea anemone; 30: Mating copepods (female with eggs); 31: Juvenile brittle star; 32: Siphonophore; 33: Ephyra larva of sea jelly; 34: Opossum shrimp, Mysidaceae; 35: Male calanoid copepod (one swollen antenna); 36: Shrimp larva; 37: Medusa of Obelia; 38: Polychaete larva; 39: Polychaete; 40: Calanoid copepod; 41: Medusa of Cladonema; 42: Polychaete larva; 43: Cubomedusa; 44: Polychaete larva; 45: Cladoceran, Penilia avirostris; 46: Shrimp larva; 47: Zoea larva of porcelain crab; 48: Megalops larva of lined shore crab; 49: Fish egg with embryo; 50: Veliger larva of gastropod; 51: Pelagic snail, Creseis sp.; 52: Hydromedusa, Corymorpha bigelowi; 53: Sea gooseberry, Pleurobrachia sp.; 54: Isopod, Paranthura elegans; 55: Polychaete larva; 56: Cubomedusa; 57: Pilidium larva of nemertean worm; 58: Polychaete larva; 59: Veliger larva of gastropod; 60: Polychaete larva; 61: Syllid worm, Salvatoria californiensis; 62: Megalops larva of swimming crab.