Dinoflagellates Geology 3213 Micropaleontology November 18 th, 2005 Ceratium lineatus Lauren MacLeod

What are Dinoflagellates? Microscopic ‘algae’- like organisms Members of the Protista kingdom 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 Protoctista Phylum Pyrrophyta Class Dinophyceae Order Lophodiniales Family Ceratiaceae Genus Ceratium C. tripos Order Peridiniales Family Gonyaulacaceae Genus Gonyaulax G. polyedra Peridiniopsis quadridens Woloszynskia coronata Note 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 cyst Systematophora penicillata Stephanelytron redcliffense a Late Jurassic dinoflagellate cyst

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 flagellates.htmlhttp:// flagellates.html uk.org.uk/mag/indexmag.html? uk.org.uk/mag/artsep01/dinof.htmlhttp:// uk.org.uk/mag/indexmag.html? uk.org.uk/mag/artsep01/dinof.html