Diversity of the Heterotrophic Plankton Community ZOOPLANKTON Diversity of the Heterotrophic Plankton Community

Major Groups of Zooplankton Ciliates Rhizopods Rotifers Cladocerans Copepods

Ciliate Zooplankton Animal-like unicellular heterotrophs. All have two different types of nuclei. They move and feed by cilia.

Some common ciliates in the microzooplankton community Stentor Halteria Tintinnida

Rhizopod Zooplankton These are amoeboid unicellular heterotrophs Most common taxa observed in the microzooplankton are thecate like Difflugia.

Actinopod Zooplankton These are free-floating cells with radiating axopods. e.g. Actinosphaerium.

Turbellarian Zooplankton These are free-living flatworms that live in stagnant pools and eutrophic lakes. e.g. Stenostomum

Rotiferan Zooplankton Animal heterotrophs that feed by ciliary pads surrounding the mouth. All have a specialized “jaws” called trophi in the gullet. Many are covered by a lorica.

Typical Life Cycle of a Rotifer

Some Rotifers in the Zooplankton Keratella Polyarthra Filinia

More Rotifers Brachionus Asplanchna Conochilus

Annelid Zooplankton Oligochaete segmented worm. e.g. Aeolosoma

Arthropod Zooplankters Most freshwater taxa are Crustaceans (arthropods with cephalothorax and abdomen) Order Anostraca Order Ostracoda Order Cladocera Order Copepoda Suborder Calanoida Suborder Cyclopoida Suborder Harpacticoida

Anostracan Zooplankton Fairy Shrimp Clam Shrimp Tadpole Shrimp

Ostracod Zooplankters Sometimes called seed shrimp. Rarely in the euplankton.

Cladoceran Zooplankton

Cladoceran Life Cycle

Filter-Feeding Cladocerans Holopedium Diaphanosoma Chydorus

More Filter-Feeding Cladocerans Daphnia Bosmina Moina

Predaceous Cladocerans Leptodora Polyphemus

Copepod Diversity Suborder Cyclopoida Suborder Calanoida Suborder Harpacticoida

Copepod Life Cycle

Calanoid Copepods Diaptomus Epischura Limnocalanus

Cyclopoid Copepods Cyclops Macrocyclops Megacyclops

Harpacticoid Copepods