Test 2 Flashcards
The marine algae are popularly known as _.
What is the more appropriate name?
Seaweeds
Macrophytes
Classification of seaweeds is based on
Pigment
Food storage products
What do seaweeds lack compared to higher plants?
Complex structures and reproductive mechanisms
S.W on rocky shores at low tide are _ and _ to withstand _ _.
small; sturdy; waveshock
Kelps found offshore in cold waters are _ _ that form _ _ _.
true giants; dense underwater forests
Seaweeds lack true _, _ and _.
Leaves, stems; roots
Complete body name
Thallus
Leaf-like, flattened portions of the thallus are known as _.
Blades
What makes blades important?
Increase surface area and are the main photosynthetic regions.
Blades are sometimes kept close to the sea surface by means of gas-filled _.
Why?
Pneumatocysts
To maximize exposure to sunlight
Stem-like structure on seaweeds
Stipe (from which the blades originate)
Anchors thallus
Holdfast
Most are freshwater, 10% are marine
Green algae
Pigments of green algae?
Food storage product?
Same as higher land plants
Chlorophyl a,b and carotenoids
Starch
Algae that has predominance of yellow pigments a and c
Brown
Brown algae charcteristics
Most dominant primary producers on temperate and polar rocky coasts; most complex and largest
Can withstand exposure to air
Brown algae characteristics p.2
Blades up to 3m in length, harvested for food. Blades may be single or split or branch. several blades may grow from a single holdfast
Brown algae characteristics p.3
largest kelps are found in deeper water below the lowest tide level
Bullwhip kelp, nereocystis, long whip-like stipe of 30m.
Pelagophycus has antler-like branches
Largest kelp
Macrocystis
Macrocystis _: Several long stipes grow from the _, from which _ _ develop.
Pyrifera; holdfast, elongate, blades
Many plants, each with many fast-growing and intertwined stipes, form dense and very productive _ _ or _ _
kelp beds; kelp forests
Algae that has more species of marine
Red algae
Examples of Red algae
Porphyra; carrageenan; agar
Coralline red algae
Deposit calcium carbonate around cell walls;
Some coralline red algae grow as _ or _ on rock. Warm water species _ coral reef debris together in the formation of _ _.
smooth; encrusting; cementing; coral reef
Reproduction of seaweeds: Sexual and asexual means; alternation of generations…
Haploid gametophyte and a diploid sporophyte
Asexual
fragments of the thallus may grow into new individuals (Sargassum)
_ _ divides by _ – haploid _ – into _ _ — produces _ _.
diploid sporophyte, meiosis, spores, haploid gametophyte, haploid gametes.
Truly marine flowering plants; rarely exposed by low tide, submerged by seawater; not true grass, closest relative - lily
Seagrasses
Seagrasses have no need to attract insect pollinators because their _ and _ are _.
pollen and tiny seeds; distributed by water and in the feces of herbivorous fish and invertebrae.
Salt-marsh plants
Cord grasses, true grass, not really marine but tolerate salt
Mangroves are adapted to live along _
They tolerate _.
tropical and subtropical shores around the world.
salt
Subtidal zone (sometimes called sublittoral)
The part of the continental shelf that is never exposed at low tide.
Surface water in N. hemisphere flow in clockwise gyre. Currents that flow _ the poles on the western sides of the oceans carry _ water from _ _.
As a result, on the _ sides of oceans, kelps are at _ _.
Kelps extend to _ _ on shores on the _ sides of oceans.
toward; warm; equatorial regions;western higher latitudes; lower latitudes; eastern
3-D structure of kelp communities
Holdfasts: polychaete worms, small crustaceans, brittle stars
Blades: tube dwelling polychaete worms, bryozoans
rocky bottom around kelp plants: sponges, sea squirts, lobsters, crabs, sea stars, abalones, octopuses.
Another name for the intertidal
Littoral zone
Emersion
Being out of water and exposed to air
Immersion
Placed underwater
Rocky shores generally occur on _ _ that lack large amounts of sediment.
Causes?
steep coasts;
Land recently uplifted or is still rising as a result of geological events
Intertidal Zonation
Splash zone; Upper; Middle; Lower intertidal
The highest area of the _ _ _ is only submerged at the _ of the _ _ and then only briefly.
upper intertidal zone; peak of the high tide
Marine organisms tend to _ _ or _ when they are out of water.
dry out; desiccate
To survive in the intertidal, organisms must _ _, _ or both.
prevent desiccation; tolerate it or both
Most intertidal organisms cope with this by either _ and _ or they _ _
run and hide; clam-up
Define run and hide
Examples?
Favorite places to hide?
As the tide goes out, the organism simply moves somewhere wet and waits for the tide to come back in.
Fish, shore crabs, snails, limpets
Tide pools (some areas are kept moist by spray or by water that slowly leaks out of tide pools)
Other hiding places?
What about Sessile animals and seaweeds? Why?
Mussels (Mytilus sp.) form dense clumps that retain moisture and provide a place for a variety of small organisms.
They live in moist areas all the time. Larvae settle only in moist, shady places or because larvae that settle elsewhere dry out and die.
Clam-up
Examples?
Organisms that use this strategy have some sort of protective covering (a shell) that they can close to hold in water.
Barnacles and mussels
are completely enclosed and can seal in moisture
simply by closing their shell.
What about Limpets?
Limpets, have an opening that cannot be completely shut.
These organisms typically clamp themselves tightly to the rock to seal the opening.
Other problems caused by emersion:
Ocean temperatures are _ _ and mild because of _.
Air?
relatively constant; high heat capacity of water;
Air temp can be more extreme. At low tide, intertidal organisms are at the mercy of the sun’s heat and freezing cold of winter
Snail adaptations to temperature
The color of the shell; ridges on the shell to act as a radiator
Temperature and salinity in tide pools
Tide pools are shallow, and experience extreme temperatures
but not as extreme as air temperatures.
At low tide the pool may be diluted by rain,
lowering the salinity.
On hot, dry days, salinity goes up as a result of evaporation.
To cope with this variation, tide-pool organisms can usually withstand a wide range of salinity,
as well as temperature.
Some may burrow or reduce their activity to ride out the extreme salinity and wait for high tide.
Deposit feeder
an animal that feeds on organic matter that settles on the bottom
Suspension feeder
An animal that feeds on the particles suspended in the water
Filter feeder
A suspension feeder that actively filters food particles
Limitations to feeding
- little sediment discourages deposit feeders
- most sessile animals are filter feeders but can’t feed when the tide is out (clam-up instead) (sea stars)
- Many mobile animals in the rocky intertidal are grazers that scrape algae, bacteria and other food from the rocks
Limits to feeding cont.
Predators search the rocks for prey
- animals that live low in the intertidal can spend the day feeding because they are submerged
Higher in the intertidal, animals may not be _ long enough to get adequate feeding time. This may cause them to _ more slowly, than they would or prevent them from living high in the intertidal at all.
submerged, immersed, underwater; grow
Describe distribution of wave energy
Waves approach the shore at an angle. Some areas are sheltered from the surf (enclosed bays), others are fully exposed.
Refraction of waves?
Effects?
One end of the wave reaches shallow water before the other, slowing down as the other end continues at the same speed. This leads to wave bending or refraction, which results to the wave becoming nearly parallel to the shore.
Can produce complicated wave patterns. headlands. bays tend to get less wave energy because of refraction. Tremendous variation of wave impact from place to place on the shore.
Coping with wave shock
Some intertidal organisms are only found in sheltered locations.
often delicate, cannot keep firm grip on rocks
tolerate sediment better than organisms that live on exposed coasts
Coping with wave shock cont.
Sessile organisms anchor themselves firmly:
seaweeds use holdfasts or encrust on rocks
Barnacles use glue
Mussels use byssal threads
Mobile chitons and limpets use muscular foot.
Coping with wave shock pt. 3
Gobies and clingfishes use modified fins to form a type of suction cup.
Intertidal fishes tend to lack a swimbladder, so they sink and stay on bottom
Exposed organisms:
have thicker shells, compact shape, low profile close to the rocks.
