During the first section

1

• During the first section
• we discussed basics of
• marine science.
• Now well begin taking
• a look at marine life and
• all of its diversity.

2
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, little
extremophiles (Fly towards the sun) 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) Courtesy
Arjen Lucassen
3
The Microbial World
4
(No Transcript)
5
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.

6
From the largest
Whale shark, Rhincodon typus
7

• To the smallest

Octopus larvae
8
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

9

• 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
10
(No Transcript)
11
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 fishs trick for
  attracting prey, or giving a good buzz to your
  fugu sushi, bacteria occupy some amazing niches
  in the marine world!

12
(No Transcript)
13
CyanobacteriaRed 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)
• .

14
Archaea Extreme Conditions

• Archaea are similar to bacteria, but they are
  able to tolerate conditions most other bacteria
  wouldnt be caught dead around...
• okay, maybe they would be caught dead hear!
• Some are able to tolerate temperatures near
  hydrothermal vents (176F, 80C).

15
Prokaryotic Metabolism
16
How do you eat??

• Many bacteria (autotrophs) are perfectly capable
  of feeding themselves, making their own organic
  compounds by photo- or 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.

17
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.

18
Unicellular Algae

• Being composed of one cell isnt 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!

19

• 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.

20
Diatoms reproduce asexually (cell division) and
sexually (auxospore), depending on external
conditions.
21
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
22
Slilicoflagellates are characterized by
star-shaped internal skeletons. Some may be used
for aging marine sediments.
23
Still others, like these Coccolithophorids are
surrounded by shells of calcium carbonate (CaCO3)
and are responsible for significant primary
production!
Umbilicosphaera sibogae
24

• 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.

25
The outer shell, or test, is made of CaCO3 and
serves as a protective structure.
26
Ciliates are protozoans which utilize cillia for
feeding and in some cases locomotion.
27
(No Transcript)
28
Bahia Fosforescente, Puerto Rico
At night this bay is illuminated by Pyrodinium
bahamense, a phosphorescent dinoflagellate.
29
(No Transcript)
30
(No Transcript)
31
(No Transcript)