Dinoflagellates

Geology 3213

Micropaleontology

November 18th, 2005

Ceratium lineatus

Lauren MacLeod100056772

What are Dinoflagellates?

• Microscopic ‘algae’-like organisms

• Members of the Protista kingdom

• 20-150 µm • The theca is

made of

cellulose

plates

Ceratium hirundiella, a freshwater dinoflagellate

What are Dinoflagellates?

• 90% are marine plankton

• ½ are photosynthetic

• Many can be found as symbiotic partners to sponges, corals, jellyfish and flatworms

• Dinoflagellates are primarily asexual, and reproduce by mitosis, only a few species have been found to reproduce sexually

Florentinia SEM Image

Taxonomy

Kingdom ProtoctistaPhylum Pyrrophyta

Class DinophyceaeOrder Lophodiniales

Family CeratiaceaeGenus Ceratium

C. triposOrder Peridiniales

Family GonyaulacaceaeGenus Gonyaulax

G. polyedra

Peridiniopsis quadridens

Woloszynskia coronataNote the sulcul flagellum

Morphology

Longitidunal

Life Cycle

Movement

• Dinoflagellates move by ‘whirling’ their flagella, and swim in a spiral fashion

• Species such as Ceratium are slow moving, while Gyroidinium are fast moving

Gyrodinium spiralis

Ceritinium ranipes has‘arms’ that look like a frog’s legs

Bioluminescence

• Members of the phylum Phyrrophyta, meaning ‘Fire-Plant’

• Produce light when LUCIFERIN is oxidized by LUCIFERASE (enzyme), when ATP and oxygen are present

• The dinoflagellates glow as it gets dark and brighten when agitated (such as in the wake of a ship)

• Noctiluca was the first genus where this was noted, but it has been discovered that it occurs in several marine species

Red Tides

• Late summer, upwelling causes a burst of dinoflagellates (up to 20 million/liter), causing the water to have a reddish color

• The dinoflagellates produce high quantities of neurotoxins which travel up the food chain

• Humans are influenced by contracting CIGUATERA and then PSP or paralytic shellfish poisoning

• Saxitoxin – 100,000 times more potent then cocaine

• Gessnerium monilatum is the most common PSP producer in the N. Atlantic

Palentological Significance

Triassic to Pleistocene dinoflagellate

zonations are correlated with:

1. Cretaceous to Tertiary planktonic foraminiferal and calcareous nanofossil zones

2. Jurassic and Cretaceous ammonite zones

3. An absolute time scale and sequence stratigraphy.

Fossil Record

• Dinoflagellate cysts were first found in late Triassic rocks

• Diverse and abundant cysts increase in Md. Jurassic

• Cysts still occur in present marine sedimentary rocks and some non-marine strata

Late Jurassic cystSystematophorapenicillata

Stephanelytronredcliffense a Late

Jurassic dinoflagellatecyst

Pfiesteria piscicida

• This unique species of recent dinoflagellate is a “Fish Killer”

• It produces a toxin which attacks the surface of fish

• Once the toxin attacks the surface of the fish, P. piscicida feeds on the disaggregated and decomposing fish carcass

Other Dinoflagellate Forms

References• http://hjem.get2net.dk/niels_e_poulsen/dino/dino-uk.htm• http://www.lifesci.ucsb.edu/~biolum/organism/pictures/dinos.html• http://www.ucl.ac.uk/GeolSci/micropal/dinoflagellate.html#range• http://www.geo.ucalgary.ca/~macrae/palynology/dinoflagellates/

dinoflagellates.html• http://geology.er.usgs.gov/paleo/dinoflag.shtml• http://www.ucmp.berkeley.edu/protista/dinoflagellata.html• http://www.ucmp.berkeley.edu/protista/dinoflaglh.html• http://www.microscopy-uk.org.uk/mag/indexmag.html?http://

www.microscopy-uk.org.uk/mag/artsep01/dinof.html