MARINE HETEROTROPHIC PROTISTS

Keeling et al. 2005 Trends in Ecology and Evolution vol 20 p.670-676

heterotrophic

mixed

Eukaryote groups

highlighting marine bacterivorous

groups

• Flagellates (pico, nano, micro)

• Ciliates (micro)

• Amoeboid (nano to macro)• Phaeodaria

silica skeleton

• Acanthareastrontium sulfate

• Foraminifera (1 mm) calcium carbonate shell

PROTISTAN PREDATORS

Picophagus flagellatus (Roscoff Plankton Group)

Symbiomonas scintillans (Roscoff Plankton Group)

HETEROTROPHIC PICOEUKARYOTES

1 µm

0.5 µm

0.2 - 2 µm

Mastigonemes

D. J. Patterson

Tamara Clarke

Patterson & Fenchel 1990 MEPS 62: 1-19

D. J. Patterson

Massisteria marinaCafeteria roenbergensis (Bicosoecids)

Heterokonts

HETEROTROPHIC NANOFLAGELLATES

2 - 20 µm“HNAN”

HETEROTROPHIC NANOFLAGELLATES

2 - 20 µm“HNAN”

Bodo saltans (Bodonid)

D. J. Patterson

Paraphysomonas imperforata (Chrysomonad)

2 µm 0.5 µm

Siliceous scales

Heterokonts

Monosiga (Choanoflagellate)

Choanoflagellates are closest protistan relative to animals

HETEROTROPHIC NANOFLAGELLATES

2 µm 1 µm

5 µm

1 µm

2 µm 2 µm

Unikonts

MICROZOOPLANKTON (20-200 µm)

Dictyocysta mitra (J. Dolan)

Strombidium inclinatum (Modeo et al. 2003 J. Euk.

Microbiol.)

Laboea strobila (Agatha et al. 2004 J. Euk. Microbiol.)

5 µm20 µm

Fabrea salina (Photoreception and

sensory transduction group -

Pisa)

Tintinnid Oligotrich Heterotrich

CILIATES

Trichodina spp.

Peritrichia

http://fishparasite.fs.a.u-tokyo.ac.jp/Trichodina/Trichodina.htmlPicture by Gerd Gunther, courtesy 2008 Olympus BioScapes Digital Imaging Competition

HJ Clark 1866 Am J Sci

Collected at: http://skepticwonder.fieldofscience.com/2010_06_01_archive.html

MICROZOOPLANKTON (20-200 µm)

CILIATES

• Some are very small and classified as nanoflagellates

• Most are microplankton (>20 µm)

• Some heterotrophic, some autotrophic, or mixotrophic

• May be armored (cellulosic thecal plates) or naked

• Many bizarre shapes and one huge one up to 2 mm!

• Many bioluminescent

MICROZOOPLANKTON (20-200 µm) DINOFLAGELLATES

MICROZOOPLANKTON DINOFLAGELLATES

40 to 60% of described species non-pigmentedMany with pigments are mixotrophic

Gyrodinium uncatenum

Noctiluca scintillans

Gyrodinium (Sherr & Sherr)

http://www.microscopyu.com/staticgallery/smallworld/2008/id2008-walz.html

Bernd Walz

Robert Brons

Shells of silica or strontium sulfate

AcanthareaPhaeodaria

MICROZOOPLANKTON Amoeboid Protists in the Rhizaria

Globigerinella

Calcium carbonate shell

Foraminifera

MICROZOOPLANKTON Amoeboid Protists in the Rhizaria

PROTIST FEEDING MODES

•Filter

•Raptorial

•Diffusive

BEHAVIORAL VARIABILITY

FLAGELLATE FEEDING

Boenigk & Arndt 2002 after Zhukov 1993

Filter

Interception

Raptorial

FLAGELLATE FEEDING CURRENTS

1 µm

Pseudobobo tremulansMonosiga sp.

mastigonemes1 µm

• No Mouth - Ingest particles mostly by phagocytosis.

What do they eat?-bacteria-phytoplankton-zooplanton

• Digest particles in food vacuole inside the cell (in some cases, outside the cell)

PROTIST FEEDING

PhagocytosisHeterotrophic

Protist Prey

Digestivevacuoles

http://mcbi.ouhsc.edu/clarkelab/phagocytosis_movies/Clarke_Movie1.mov

Dinoflagellate Feeding Modes

Phagocytosis Peduncle Pallium

Prey Handling

MIXOTROPHY

• There is spectrum of capabilities for photosynthesis among protists that consume prey.

• Some are permanent, obligatory

• Some persistent

• Some are transient

MIXOTROPHIC FLAGELLATES

Prymnesium (Prymnesiophyte)Micromonas pusilla (Prasinophyte)

Thomas, C.R. (ed.) (1997)1 µm

KLEPTOPLASTY BY A FORAM

KLEPTOPLASTY

Myrionecta rubraA ciliate steals chloroplasts from its prey ( a cryptomonad)

Geminigera cryophila

Text

Serial Kleptoplasty!