Pelagic Lite Post

7/25/2019 Pelagic Lite Post

1/44

Jellies

The Scyphozoans (sky-FOE-zo-ans), better known as!ellies, "ri#t alon$ in thewater $enerally with the%o&th an" tentacles pointin$"own' e call this a%e"&soi"bo"y #or%'

Medusa (Greek mythology): the only mortal of the three monster Gorgon

sisters with dangling snakes for hair and other lovely accoutrements (the word

Gorgon derives from the Greek for terrible or dreadful. Think of dreadlocks?)In theOdyssey,she is a monster of the underworld:"...and pale fear seized me, lest august Persephonemight send

forth upon me from out of the house of Hadesthe head of the Gorgon, that awful monster..."(11.635) [Wikipedia]
http://en.wikipedia.org/wiki/Odysseyhttp://en.wikipedia.org/wiki/Odysseyhttp://en.wikipedia.org/wiki/Persephonehttp://en.wikipedia.org/wiki/Hadeshttp://en.wikipedia.org/wiki/Hadeshttp://en.wikipedia.org/wiki/Persephonehttp://en.wikipedia.org/wiki/Odyssey


2/44

ni"ariansan in*ertebrate with stin$in$ tentacles

The +y"rozoans (hy"roi"s)

an" nthozoans (ane%ones,corals) are %ostly all botto%

"wellin$ ani%als, in a

polypoidshape' This %eans

that they li*e attache" to the

botto% with their tentaclesan" %o&th pointin$ &p'


3/44

haeto$nathshairy %o&th

n the worl" o# the plankton,

the chaeto$naths (arrow-

wor%s) are aweso%e

pre"ators, instantly s&b"&in$their prey with slashin$

*eno%o&s bristles, #ollowe"

by *ery rapi" "i$estion'

alanoi" copepo"s are a

#a*ore" prey'


4/44

Arthropods:lobsters, shrimps, crabs, krill,

barnacles

most successful animal group

(over 80% of phylum animalia)

includes insects, arachnids, and

crustaceanshave tight-fitting exoskeletons

and a segmented body with

appendages on each segment

occupy greatest no. of habitats

Shrimp alone account for more

than 2000 species

Homarus americanus

Eggs


5/44

Swi%%ers%ore co%ple. strate$ies #or s&r*i*al

S/&i"

Fish

0arine %a%%als


6/44

Cephalopods: Squids, nautiluses and octopuses


7/44

40 tons of acrobatic grace: The Humpback Whale

MARINE

MAMMALS


8/44

0arine 0a%%als1ll "eri*e" #ro% lan" ancestors

war%-bloo"e"

so%e ha*e hair or #&r

breathe air

bear an" s&ckle li*e yo&n$2

Sirenians - sea cows (%anatees an" "&$on$s)3 (siren 4 se"&cti*e or te%ptin$ call or son$)

Fissipe"ia - sea otters (relate" to cats, "o$s)3 (#issi 4 split, separate", "i*i"e" - i'e' w5 toes6)

7innipe"s - sea lions, seals, walr&ses3 (pinni 4 lea#, #ron" or #eather - i'e' pa""les or #lippers)

etaceans - whales, porpoises, "olphins3 (cet&s 4 whale)

*exception: the duck-billed platypus (Australia)


9/44

etacea Toothe"whales, or odontoceti, incl&"e sper% whales,

porpoises an" "olphins1 acti*e pre"ators &sin$

echolocation

8aleenwhales, or mysticeti(%o&stache" whales) ha*ebaleen instea" o# teeth1 cr&isers an" strainers

8o"y is so%ewhat ci$ar shape", al%ost hairless, an"

ins&late" with a thick layer o# bl&bber


10/44

Baleen


11/44


12/44

Echolocation

hen the so&n" strikes an ob!ect, so%e o# the ener$y o# the so&n"wa*e is re#lecte"back towar"s the "olphin' t wo&l" appear that the panbone in the "olphin9s lower !awrecei*es the echo, an" the #atty tiss&e behin" it trans%its the so&n" to the %i""le earan" then to the brain' t has recently been s&$$este" that the teeth o# the "olphin, an"the %an"ib&lar ner*e that r&ns thro&$h the !awbone %ay trans%it a""itional in#or%ationto the "olphin9s brain'


13/44


14/44

The Humpback Whale: the great

communicator

Reproduction Strategies

Oviparous(most fish and invertebrates):lay eggs that hatch into larval forms.

Strategy: lay lots of eggs and hope a few

survive

Ovoviparous: Some fish and arthropod

females keep their fertilized eggs aboarduntil they hatch (e.g. lobster)

Viviparous: Mammals give birth to live

young, provide placental nourishment to

the embryo through an umbilical cord, and

(usually) post-partum nourishment bynursing. Strategy: develop and protect a

few offspring and help most of them

survive


15/44

Ambulocetus

Basilosaurus

Sperm Whale

http://en.wikipedia.org/wiki/Evolution_of_Cetaceans#Skeletal_evolution


16/44

Pinnipeds


17/44

The Blue WhaleThe Blue Whale(Mysticeti, or Baleen Whale)

Earths largest animal (100 ft long; 150 tons - comparable to a 737!)

Mammal: warm-blooded, breathes air, nurses young, large brain

Migrates between southern polar latitudes to feed and tropics to mate

Eats ~3 tons of krill (zooplankton)per daywhen feeding!


18/44

"aptations #or :epth bility to store o.y$en #or "eep "i*es

bility to re"&ce o.y$en "e%an"

;ow s&sceptibility to nitro$en narcosis

The sperm whales are known to

dive to at least 2200 m (7200 ft)The bottle-nosed dolphin can stay

submerged for up to 2 hours

Cetaceans have large concentrations

of blood capillaries surrounding the

alveolar membranes in their lungs


19/44

Seasonal Migration routes of the California Gray Whale:from the Arctic in the summer to the tropics in winter (22,000 km roundtrip)

Grays are baleen whales, but they feed onbottom-dwelling amphipods (shrimp-like

zooplankton) by stirring up bottom

sediments with their snouts

Hunted nearly to extinction until the

International Whaling Treaty of 1938banned the taking of gray whales


20/44

World Whale Populations

Current (red) and pre-whaling (green)

A minke whale in NY harborApril 17, 2007


21/44

8&oyancy ontrol1 Swi%

8la""ers 0any %arine #ish

ha*e $as #ille"or$ans calle" swi%bla""ers'

These or$anscontrol b&oyancy

an" allow the #ish to%aintain a certain"epth in the watercol&%n'


22/44

Fish ;oco%otion

8asic %o*e%entis lateral bo"yc&r*at&re #ro%#ront to back o# the#ish

0yo%eresare%&scles on thesi"e o# the #ishthat alternati*elycontract an" rela.


23/44


24/44

irc&latory syste% a"aptations

(e.g. tuna)(e.g. grouper)

Cold-blooded warm-blooded


25/44

Anadromousfish

spawn in freshwater

live in open ocean

ana = up

Catadromousfishvice-versa

cata = down

Chinook

Coho

Chum


26/44

Schooling

Going

Rogue

Uh-oh


27/44

Schooling: safety in numbers?

GOOD

reproduction: males always handy

occupy smaller percentage of ocean volume - harder for predators

school may look like single large fish - discourage the bad guy

schooling behavior may confuse predators - coordinated zigs and zags

drafting - bicycle racers ride in teams; standard NASCAR tactics

NOT SO GOOD

strainers love schools - just slurp them up

requires good communication between individual fish to avoid chaos (think

what happens when one of the tubas in the Aggie Band turns at the wrong time)

requires a few leaders and lots of followers - do fish have egos?


28/44

The Deep-Sea Gulper (an eel, actually)

The Lantern Fish

Strange denizens of the reallydeep

Two small eyes;

depths 3000-

6000 meters

(almost Nemos nemesis)


29/44

Deep-sea adaptations for eating:

You dont get to do it often, so

make it worthwhile when you do


30/44

Green Sea Turtle

Marine Reptiles: Turtles, Sea Snakes, iguanas, crocodilesectothermic (cold-blooded), air-breathing

Dude! Were, like, here!


31/44

NEMOS MOMS

DEMISE: The Barracuda(a.k.a. Baccaruda)


32/44

The ha%bere"

= "!&sts its "epth between the

s&r#ace an" at least ?@@ %eters by

p&%pin$ water in or o&t o# its shell


33/44

Marine Birds: Latter-Day Dinosaurs:

Gulls, Pelicans, Albatrosses, Petrels, Penguins (flightless), Boobies

Endothermic (warm-blooded)

Reptilian heritage (evolved

from small dinosaurs)

Feathers are derived from scales

Black-footed

albatrossWingspan ~3 m

`God save thee, ancient Mariner !From the fends, that plague thee thus !--

Why look'st thou so ?'--With my cross-o

" shot the #$%#&())* +ime o the #ncient mariner, )amuel &aylor oleridge, ./012


34/44

oral Aee#s

Breatest known ani%al "i*ersity o# any

%arine co%%&nityC abo&t D o# all

%arine species Typically #o&n" where te%perat&res

a*era$e o*er GH= but less than 30C

Aee# $rowth re/&ires relati*ely nor%alsalinity an" clear water

30 C = 86 F


35/44

HERMATYPIC

CORAL (reef-

building);

Symbiont zooxanthellae(dinoflagellates)-

mutualism

Rigid CaCO3 structure

Relative of the anemone

Fresh water is fatal!

Need clear, warm, well-

lighted seawater

Greatest Atlantic Ocean

reef diversity in theCaribbean Sea

But highest world-wide in

western Pacific


36/44

Coral Reef Distribution (note 18 C limit; greatest diversity in W.

Pacific)


37/44

Individual corals (polyps) are small, benthic marine animals that feed

with stinging tentacles, similar to anemonies but much smaller

Corals construct hard structures from calcium carbonate, producingaccumulations called reefs

Most reef corals host a symbiotic partner calledzooxanthellae, a

photosynthetic algae that makes much of the food used by the coral. The

algae benefit from nutrients (waste products) from the corals.

This type of mutualistic symbiosis characterizes hermatypic corals

To survive and prosper, hermatypic corals require strong sunlight,

temperatures in the 18-30 C range, clear water, oceanic salinities, and a

hard substrate

Some non-hermatypic corals survive in deep, cold waters.


38/44

Flower Bar"ens


39/44

Why do it that way?

Corals are captive, so the massive synchronized spawn produces large clouds of

gametes (eggs and sperm) that offer genetic diversity that can be spread over alarge area by ocean currents

The newly hatched larvae, called planula, rise to the surface and float with the

currents for a few days to a month or so, after which they sink to the bottom

If a suitable benthic substrate is available (typically older coral structures), theplanula attaches and grows into a new polyp, which grows into a coral head by

asexual budding that creates new polyps.

www.scubadiving.com/article/news/full-moon-trigger-coral-spawning-florida-keys-reefs

Such a copious delivery system, called broadcast spawning, maximizes the

chances of fertilization, and at the same time overwhelms predators with

more food than they can consume.


40/44

Aee# 8&il"in$

0ost her%atypic or ree#-b&il"in$ corals host sy%biotic"ino#la$ellate al$ae insi"e their tiss&es'

oral polyps also &se their tentacles an" ne%atocyststo #ee", b&t the al$ae pro"&ce %ost o# a coral9s #oo"'

Aee# corals are e.cl&si*ely shallow-water "wellersC

witho&t li$ht they cannot s&r*i*e

Blobal war%in$ an" risin$ sea le*els har% coral ree#s'


41/44

Threats to oral Aee#sPhysical damage by humans: fishing, anchoring, sampling,

increased sediment loads, sewage discharge

take pictures, not samples!

Nutrient over-enrichment: phytoplankton blooms, decreased

water clarity, fungal attacks

Bleaching: increasing temperatures can expel the symbiotic

algae, causing death of the coral - El Nino

Crown-of-Thorns sea star destroys coral


42/44

Crown-of-Thorns Sea Star

Eats live coral voraciously

Only venomous sea star

Can have many arms - up to 26!

Long, sharp, poisonous spines

Principal predator: the Giant Triton


43/44

A few oyster factoids:


44/44

Fair winds

And following seas

Documents

Pelagic Lite Post