The document summarizes key details about dinoflagellates: - Dinoflagellates are unicellular plankton that are 90% marine, with some freshwater and symbiotic species. About half are photosynthetic. - They reproduce primarily asexually through mitosis, though some reproduce sexually. Their cell coverings can be armored or unarmored. - Some species produce bioluminescence or toxins that can harm humans and fish. Dinoflagellate blooms can discolor water. - Dinoflagellate cysts are found in sedimentary rocks from the Triassic period to present.

1. BIO 14 YA
June 29, 2013

2. • Dinozoa or Pyrrophytes
• 90% are marine plankton
• ½ photosynthetic
• Unicellular or in aggregations
• symbiotic partners to sponges, corals, jellyfish
and flatworms
• primarily asexual, and reproduce by mitosis,
only a few species have been found to
reproduce sexually

3. • Cell covering is
called Amphiesma
that often forms
plates
• Made up mainly of
cellulose
• Grouped into two:
• Armored/thecate
• Unarmored/athecate

5. • Biflagellate
• Longitudinal and
transverse flagellum
• Several thecal
plates
• Cingulum vs sulcus

7. • Commonly in
reddish – blood red
– deep red in color
• Different species
gives different water
color
• Can discolor water
when in bloom

8. • Very diverse in size
• Some have rigid
walls others have
none
• Two types of
dinoflagellates
based on
presence/absence
of armor: armored
and naked

11. • Some species of
dinoflagellates (Gonyaulax,
Pyrodinium, Pyrocystis,
Noctiluca) are luminescent
• They emit flashes of light in
response to mechanical
disturbance of the water.
The light is produced by an
enzymatic reaction

13. • Most of them are found in oceans (very
few are freshwater).
• Planktonic, few are benthic and some
enter into symbiotic relationships.
• Autotrophic-Heterotrophic forms. Parasites
of invertebrates and fishes.

14. • Late summer, upwelling
causes a burst of
dinoflagellates (up to 20
million/liter),
• 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

15. • SAXITOXIN
(Alexandrium)-neurotoxin.
• BREVETOXIN
(Gymnodinium)
• CIGUATOXIN
(Gambierdiscus) –
Ciguatera poisoning
(eating contaminated fish)
• OKADAIC ACID
(Dinophysis)-causes DSP

16. 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.

17. • 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
•
Stephanelytron
redcliffense a Late
Jurassic dinoflagellate
cyst
Late Jurassic cyst
Systematophora
penicillata

18. • 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

19. • Some
photosynthetic
dinoflagellates
(Symbiodinium) are
found in cells of
many hosts like
protozoa, clams,
flatworms, jellyfish
and corals.