Transcript Red tides (Karenia brevis)

• During the first section
we discussed basics of
marine science.
• Now we’ll begin taking
a look at marine life and
all of it’s diversity.
Find your way home, little extremophiles
(Fly beloved sons)
Find your way home, donors of life
(Fly my chosen ones)
You're on your own, little extremophiles
(Ride your frozen ark)
You're on your own, cleaving the skies
(Ride into the dark)
Carry out our dangerous task
Sail uncharted spheres
Live out our dreams, ride the comet
Journey on the Migrator trail
Cross the new frontiers
Pass on our genes, ride the comet
You are the future, you know what to do
(Fly it has begun)
Carry out our dangerous task
Sail uncharted spheres
Live out our dreams, ride the comet
Journey on the Migrator trail
Cross the new frontiers
Pass on our genes, ride the comet
Carry out your dangerous task (Carry on)
Sail uncharted spheres (Hey, hey)
Live out our dreams
Ride the comet (You ride the comet)
Journey on the migrator trail (Migrator trail)
Cross to new frontiers (Oh yeah)
Pass on our genes
Ride the comet (Yeah, yeah, yeah, yeah)
You are the future, little extremophiles
(Fly towards the sun)
Courtesy: Arjen Lucassen
The
Microbial
World
Introduction
• We begin our survey of ocean life with the smallest of marine
organisms, the bacteria and archea.
• Both groups contain members which are capable of
photosynthesis an are known as primary producers.
• These primary producers are responsible for directly or
indirectly feeding most marine organisms.
From the largest…
Whale shark, Rhincodon typus
To the smallest…
Octopus larvae
Prokaryotes
• The first organisms we will consider will be the
prokaryotes.
• Prokaryotes are the smallest, simplest (and oldest)
organisms around.
• Unlike other animals we will study, prokaryotes lack
a nucleus.
• Two main categories of prokayotes are Archea and
Bacteria
• Marine bacteria take on many
shapes, including spheres such
as Thiomargarita namibiensis,
a benthic bacteria which can be
seen with the naked eye.
• Other shapes include rods, rings
and spirals.
• Some may form into
large calcium containing
mounds (stromatolites).
• Still others break down organics
and cycle nutrients.
Stromatolites, Exuma Cays, B.I
Life and Death
•
Perhaps one of the most interesting
evolutions of bacteria cocerns the
development of bioluminescence
and toxins (tetrodotoxin).
•
Whether used as a flashlight fish’s
trick for attracting prey, or giving a
good buzz to your fugu sushi,
bacteria occupy some amazing
niches in the marine world!
Cyanobacteria:
Red Tide
• Planktonic spp. such as
cyanobacteria (which can
cause red tides) often multiply
very rapidly.
• The contain red pigments!
Go figure…
• Red tides (Karenia brevis)-can be caused by
dinoflagellates too (photo)
.
Archaea: Extreme Conditions
• Archaea are similar to bacteria, but they are able to tolerate
conditions most other bacteria wouldn’t be caught dead around...
okay, maybe they would be caught dead hear!
• Some are able to tolerate temperatures near hydrothermal vents
(176°F, 80°C).
Prokaryotic Metabolism
How do you eat??
• Many bacteria (autotrophs) are perfectly capable of feeding
themselves, making their own organic compounds by photoor chemosynthesis.
• Bacterial photosynthesis can be different than that found in
plants (i.e. you might produce S instead of O2).
• Some autotrophs which produce methane as products are
being used to meet our energy needs.
How do you eat (cont.)??
• Bacteria which utilize other sources of carbon (organics) to
exist are known as heterotrophs.
• Many heterotrophs are involved in decay processes and
some even exist in anoxic (no O2) conditions.
• Still others are actively fixing nitrogen from gas to
molecules which other animals can use as food during
primary production.
Unicellular Algae
• Being composed of one cell isn’t an evolutionary
dead end.
• Alagae, Diatoms, Dinoflagellates, and Radiolarans
all have been aound for millions of years (if not
billions).
• Being eukaryotic, unicellular organisms such as these
use a variety of methods to eat, metabolize, and
reproduce.
• As a group these organisms are known as Protist!
• Diatoms contain many organelles that enable them
to exist under potentially harsh conditions.
• Most diatoms constist of strikingly delicate outter
shells of SiO2 (frustules) which provide limited
protection and light penetration.
Diatoms reproduce asexually (cell division) and sexually
(auxospore), depending on external conditions.
Dinoflagellates exhibit two flagella which permit movement.
Theca
Groove
One flagella is
located within the
groove and the other
is located at the lower
end (not visible).
Dinoflagellate, Gonyaulax polyedra
Slilicoflagellates are characterized by star-shaped internal
skeletons. Some may be used for aging marine sediments.
Still others, like these Coccolithophorids are surrounded by
shells of calcium carbonate (CaCO3) and are responsible for
significant primary production!
Umbilicosphaera sibogae
• Some eukaryotes are more like animals than like plants!
• In fact, having a single cell is about the only thing that
these critters have in common with other eukaryotes we
have observed.
• Foraminiferans and radiolarans
utilize specialized pseudopodia
(spine-like projections) to capture food.
The outer shell, or test,
is made of CaCO3 and
serves as a protective
structure.
Ciliates are protozoans which utilize cillia for
feeding and in some cases locomotion.
Bahia Fosforescente, Puerto Rico
At night this bay is illuminated by Pyrodinium bahamense,
a phosphorescent dinoflagellate.