Karl Van Ginderdeuren/World Register of Marine Species

COMB JELLY HYDROMEDUSA

Photo by Heather Malcom

Photos from © www.micrographia.com COPEPODS WATER FLEA

Photo by Piet Spaans Photo by Marco Spiller

PHANTOM MIDGE LARVA ROTIFER

ZOOPLANKTON of the HUDSON RIVER ESTUARY HYDROMEDUSA COMB JELLY What is it? Sarsia tubulosa is a hydrozoan; related to jellyfish & sea anemones What is it? Mnemiopsis leidyi is a ctenophore; How big is it? to ¼ in. across unlike jellyfish, it lacks stinging cells What does it eat? tiny zooplankton How big is it? species shown (up to 4 in. long Where does it live? ocean, estuaries, bays; What does it eat? smaller zooplankton, larval brackish & salt water fish, fish eggs What is its life cycle? alternates body form; Where does it live? ocean, estuaries, bays; planktonic hydromedusae release eggs that brackish & salt water hatch & become hydroids - plant-like forms What is its life cycle? hatches from egg; fixed to the bottom; hydroids produce buds young generally look like adult that break off to become new hydromedusae

WATER FLEA COPEPODS What is it? Bosmina freyi is a ; What is it? crustacean; one of many species in water fleas are properly called cladocerans Cyclops (left) & genus Diaptomus (right) How big is it? to 0.6 mm How big is it? species shown less than 2 mm 1 What does it eat? detritus, algae, plants; ( /10 in.) long some water fleas eat tiny zooplankton What does it eat? detritus, algae, smaller Where does it live? lakes, ponds, rivers, marshes, estuaries, bays; fresh & brackish Where does it live? ponds, lakes, rivers, water marshes, estuaries, bays, oceans What is its life cycle? hatches from egg; What is its life cycle? egg hatches into looks a little like adult but molts many times nauplius larva, which after 5-6 molts becomes before maturing copepodid larva; becomes adult after 5 more molts

ROTIFER PHANTOM MIDGE LARVA What is it? an in phylum Rotifera; What is it? an insect; one of many species many species in genus Chaoborus 1 How big is it? up to 2 mm ( /10 in.) long, but How big is it? species shown up to ¾ in. long most are much smaller What does it eat? larva eats small What does it eat? detritus, algae, bacteria, crustaceans, other zooplankton & other tiny zooplankton Where does it live? ponds, lakes, rivers, Where does it live? lakes, ponds, rivers, marshes; fresh water marshes, estuaries, bays; fresh & brackish What is its life cycle? larva hatches from water egg laid in water; a few weeks or months What is its life cycle? hatches from egg as later forms a pupa; after a few days a tiny version of adult flying adult emerges - it lives up to a week

ZOOPLANKTON of the HUDSON RIVER ESTUARY