MARE 194

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MARE 194

• Symbiosis on the Reef, Predation, Competition

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Species Interactions

• Sp1 Sp 2
• 0 0 neutral
• mutualism
• 0 commensalism (epiphytes)
• - predation, parasitism, disease
• - - competition

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Symbiosisdefined

• An association between 2 or more organisms
• On the reef, many organisms have a symbiotic
  relationship w/ coral

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2 Types of Symbiosis

• Obligate organisms cant live without the
  association
• Corals zxth

• Facultative association is not required, but
  organism is more successful w/ the association
• Anemone fish anemones

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Corals Tolerate Symbionts Well

• With zxth, function as primary producers (?
  source of organic C)
• Asexual reproducers?they can regenerate a large
  amount done by symbionts/predators
• Mucus formation feeds commensals free-living
  organisms
• Skeletons provide many niches

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MUTUALISMS
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Cleaning Stations

• Mutualism, or is it?

• Cleaner Wrasses set up stations on outcroppings
• Males maintain harem of females
• Each female maintains own station

BUT Wrasses may take bites of scales or flesh
PREDATOR!
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Cleaning Stations

• Brave wrasses are dentists
• Shrimp as Cleaners

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Cleaning Stations

• Green Sea Turtle Cleaning Stations

Saddle Wrasses ? feed on barnacles
Kole (Goldring Surgeonfish) ?may be picking at
flesh/tumors
Surgeonfish ?eating algae on shell
MUTUALISM!
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Cleaning Stations

• Green Sea Turtle Cleaning Stations

Surgeonfish ?eating algae on shell
Saddle Wrasses ? feed on barnacles
MUTUALISM!
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Anemone Hermit Crabs

• Carries anemones on shell
• Increased camoflauge
• Protection from parasites

MUTUALISM!

• Anemone will be moved when crab outgrows shell!
• Get protection
• Transport
• Free food from messy eater

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Come on and take a Free Ride

• Sponge Crabs Sea Sponges
• Crabs back legs modified to carry sponge
• Sponges have toxins as defense ? defend crab from
  predators
• Sponges dont have to compete for space on reef

MUTUALISM
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Sharing Your Digs

• Hawaiian Shrimp Goby Shrimp
• Shrimp digs burrow
• Goby shares burrow
• Benefit?
• Shrimp is nearly blind
• Goby protects entrance to burrow, warns shrimp of
  danger
• Shrimp is protected, Goby gets cover

MUTUALISM!
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COMMENSALISMS
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Living Where the Sun Dont Shine

• Black Sea Cucumbers Sea Cucumber Crab
• Lives in anus of
• sea cucumber
• Emerges to look for
• parasites on cucumber
• Takes cover from
• predators in anus

COMMENSALISM!
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Trapped for Life

• Gall Crabs Lace Coral
• Female crab settles in lace coral
• Coral colony grows around it ? creates gall
  chamber
• Female too large to leave
• Small male enters to breed
• Young larval crabs exit through hole

COMMENSALISM!
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PARASITISM
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Living Where the Sun Dont ShinePart II

• Banded Sea Urchins Sea Urchin Crabs
• ? crabs live in rectums of urchins
• Feed on fecal pellets of urchin
• ? crabs live among
  spines much
  smaller
• Banded Sea Urchins
  w/ INTACT anal
  sacs dont have a
  crab
• Crabs destroy sacs
  to enter rectum

PARASITISM
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PREDATION !
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Two Kinds of Predators

• Ambush take prey by surprise with a rapid dash.
  Common for bottom dwellers
• achieved by using all their available fins, beat
  powerfully w/ entire rear portion of bodies
• Sneak-up high utilization of camouflage

Frogfish also use a lure
Cuttlefish make themselves look like their
environment
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The Dragons of the Reef

• Moray Eels
• Made to be predators
• Search Image (diurnal feeders)
• Palatine Teeth ? clamp food to avoid losing it to
  currents ?choke down food

Lizardfish have arrowhead-shaped teeth
PREDATION!
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You sneaky little

• Ewa Fangblenny vs. Reef Lizardfishes (among
  others!)
• Fangblennies mimic Hawaiian cleaners
• Advertises cleaner stations via
  movements/displays
• Attacks large prey leaves w/a tasty morsel!?and
  one shocked fish

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COMPETITION
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CORAL WARS

• Competition for SPACE
• Direct Tentacular Competition
• Mesenterial Filaments
• Bulldozing
• Shading

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CORAL WARS

• Two Types of Competition
• Interspecific between different species
• Intraspecific between 2 genetically-different
  colonies of the same species

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CORAL WARS

• Other Types of Space Competition
• Sweeper Tentacles long tentacles swaying back
  forth, preventing encroachment
• Occurring w/ territorial damselfish
• Chemical substrate zones by Cyphastrea
• Colony defense by symbionts

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CORAL WARS

• Sweeper Tentacles

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CORAL WARS

• Aggresively defend territory
• Maintain algal mats
• Corallivores cannot reach coral colony

• Territoral Damselfish

• Are the coral colonies PREDATORS?
• Directly benefit from damsels protection
• While taking up space that could be used for more
  algae growth

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CORAL WARS

• Ocellated coral secretes chemicals that prevent
  encroachment larval settlement

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CORAL WARS

• Trapezia cymodoce defends Pocillopora from being
  preyed upon by C-o-T

• First undergo
• elaborate displays
• Then breaks off
• spines as it
• approaches

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Competition for Food
Bottlenose Dolphins vs. Bigeye Trevally

• Both forage on schools of small fish
• Dolphins use echolocation to locate, then
  surprise attack
• May hunt alone
• Trevally groups hunt together via
  surrounding, cornering, confusing prey
  before the attack
• Must hunt in groups

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Competition for Mates

• Cuttlefish Males
• change appearance by opening/closing pores in
  skin (chromatophores)
• ? intimidate their opponents w/ both size more
  intense zebra patterns mate w/ ?