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MARS 3450 Exam 4 Notes

Terms in this set (90)

(i) Algal-Animal Symbiosis Mutualism

- Seen in shallow waters (Photic Zone)

- Most common in the tropics; absent in polar regions

- Cellular vs. Chloroplast Symbiosis:

Most common (cellular) Symbiont = Dinoflagellates

Most common hosts: Protists and Cnidaria

Forams with Dinoflagellate Symbionts

Flat Worms with Green Alga == Move down/out of sediment with the tides

Mollusca/Gastropod and Green Alga Chloroplasts == Chloroplast symbiosis "Kleptoplasty"

Sea Slugs == Plastids from Kleptoplasty of Green Alga by Mollusca/Gastropods encode in genome, express chloroplasts in a heterotrophic organism

**Plastid in Host: Nuclear-encoded Photosynthesis genes == Heterotrophic organism acquires Photosynthesis genes

(ii) Animal-Animal Mutualism

Clown Fish / Anemone:

- Mutual protection, clownfish protects anemone from being eaten and anemone provides shelter/camouflage for the clownfish from predators

- Clownfish pee out Ammonia and Anemone uses Ammonia for their photosynthetic symbionts' nutrients (the symbionts inside the Anemone use the Ammonia as food basically)

Boxer Crabs / Anemone:

- Hang on to Anemone on their front claws and use them to gather food (swish them in water, rub on substrate) or protection (swing the anemone tentacles around to sting predators)

- When crab molts, Anemone is attached to molt and the boxer crab takes them off the old molt to put in their new molt. Sometimes anemone will not want to leave old molt, When crabs pull anemone off old molt the Anemone could split into two

Moray Eel / Cleaner Shrimp:

- Share "avid coloration"

Pufferfish / Cleaner Wrasse

Advertisement and FALSE Advertisement:

- Bluestreak Cleaner Wrasse (Real); Bluestriped Fangblenny (Fake; but change appearance to match Bluestreak Cleaner Wrasse)

- This allows the Bluestriped Fangblenny to be able to eat the same food as the cleaner wrasse without the risk of being eaten

(iii) Animal-Animal Commensalism

Barnacales, Amphipods on Right Whales:

- "Callosites" (Right Whale Callosites ) = Barnacles

- "Whale Lice" = Amphipods; feed on dead whale skin

Commensal Crabs in Polychaete Tube:

- Pea crabs in Polychaete tube, crab benefits by living in tube and using the incurrent/excurrent siphon to catch some food; apparently the crab has no effect at all on the polychaete


(iv) Animal-Bacterial Mutualism

- Bioluminescence in fish / Bacteria

- Riftia / Sulfide-Oxidizers

These are examples of Animal-Bacterial Mutualism
By-catch == ~20 - 30% of the total global catch

- By-catch is the catch of fish that are not the target fish

- Not allowed to keep by-catch; must be thrown back

- Dolphins being caught as by-catch die in the nets catching tuna because they get trapped with the tuna; new regulations set to use Purse seine nets so that Dolphins can still escape if caught --> Rates of dolphin by-catch dramatically decreased


Changes in Predation / Competition:

Antarctic Whale Populations

- Minke whales benefited from not being fished because they were small, so while other whales were fished and their populations decreased, Minke whales population increased because of more available krill to eat due to other species of whales being fished

- Alaskan Pollock eat Zooplankton but have started being over-exploited as a fishery

- This has led to Auklets (Birds) that eat Zooplankton as well INCREASING in population due to less Alaskan Pollock eating Zooplankton so more is available for them to eat

- Kittiwake Birds eat Alaskan pollock, so because the Alaskan Pollock populations are being over-exploited and decreasing, the population of the Kittiwake Birds are also DECREASING

- Stellar Sea Lions eat large pollock, and since there is an increase in over-exploitation of catching Alaskan Pollock, there is a decrease in Pollock population size which leads to smaller alaskan pollock being available/born; thus, Stellar Sea Lion populations are declining due to the Alaskan Pollock populations declining

- This also relates to Kelp Forests, as Sea Otters are hunted by Killer Whales due to Alaskan Pollock populations decreasing in size; because of this, sea otters aren't eating the sea urchins as much and this is causing the sea urchins to take over the kelp forests and eat the kelp, making the kelp forest unhealthy (leads to overgrazed kelp forests by sea urchins dominating the areas due to less sea otters available to eat the sea urchins)