Zooplankton Identification Guide Prepared by Emi Yamaguchi & Caitlin Bell (2007)
adult copepod copepod nauplius Copepods are the most common zooplank- The nauplius is a common early larval stage of ton worldwide. They are an integral part of crustaceans. Some nauplii have spines while the food web as both predator and prey. others do not.
polychaete worm larvae barnacle nauplius cypris larva These organisms are the marine rela- Barnacle nauplii are distinguished The cypris is the final tive of earthworms. The larvae are from crab larvae by the “spikes” on larval stage of a barna- found in the plankton. The adult form, their heads. This stage comes be- cle. It must find a suit- seen in the invertebrate lab, is benthic. fore the cypris stage. able attachment site to become an adult.
tunicate (sea squirt) larva adult Oikopleura sp. This “tadpole” is an early life stage of a tunicate. This organism is actually an adult tunicate Tunicates are related to humans because they that retains its notochord and tail. The tail have a notochord, although it disappears as the beats back and forth rapidly to create a larva matures. Sea squirts, found in the inverte- current that brings food near the mouth. brate lab, are adult tunicates.
The University of Georgia Marine Education Center and Aquarium http://www.marex.uga.edu/aquarium Zooplankton Identification Guide Prepared by Emi Yamaguchi & Caitlin Bell (2007)
megalops The megalops is the final larval fish larvae stage of a crab. During this This juvenile fish will develop into a nektonic or benthic stage, the abdomen is ex- adult form. It is considered planktonic at this very young tended. The abdomen is folded stage. under the body as an adult.
veliger larva A veliger is a free-swimming larval rotifer tintinnid stage of a mollusk. Veligers have Rotifers’ cilia are in constant Often referred to as a “tintinnid the beginnings of a foot, shell, motion. Only a few species cup,” a tintinnid is a ciliate with and mantle. This photo shows a are found in marine and a hard outer covering. veliger of a Littorina snail. brackish water.
hydroid medusa zoea This photo shows the medusa stage of a hydroid. The medusa The zoea is a larval stage of a crab or stage has stinging cells for protection and food capture. This shrimp. Zoea have two large spines stage reproduces sexually to form polyps. Polyps then repro- that are used for protection and flota- duce asexually to produce the medusa form. tion.
The University of Georgia Marine Education Center and Aquarium http://www.marex.uga.edu/aquarium