FINAL MARINE BIO

What makes Water so special?

-Very polar- string M1 attraction -only substance that exists in all 3 phases solid liquid and gas -Solid ice is less dense that liquid

characteristics of Radial symmetry?

-simple -no brain required -brains are expensive and unnecessary for sedentary life style)

What is the photosynthesis equation?

6CO2 + 6H2O → C6H12O6 + 6O2

Coral reef growth is highly dependent on nutrient recycling between coral polyps and zooxanthellae in their tissues. Explain how this relationship is an example of mutualism.

A mutualistic relationship is one in which both species involved benefit from the interaction. Coral polyps and zooxanthellae exhibit a mutualistic relationship because zooxanthellae live within the coral's tissues, receiving a home and protection in addition to a steady stream of nutrients from the coral's wastes. The zooxanthellae are photosynthetic algae that convert the sun's energy into sugars and starches, which diffuse into the coral's tissues, providing the polyps with supplemental energy (corals are consumers). This extra energy allows the coral polyps to grow and build the reefs that protect the zooxanthellae and keep them near the sunlight. In short, the zooxanthellae receive nutrients that would otherwise be extremely difficult to acquire in tropical waters and the corals receive a reliable source of sugars and starches to supplement the energy they get from eating.

Why don't the nutrients in the deep water replenish the nutrients at the surface?

A strong thermocline near the base of the photic zone imparts a high degree of vertical stability to the water column and inhibits upward mixing of nutrient-rich waters. Stratification of the water column prevents diffusion of nutrients in the deep water up into the photic zone because the different layers of the ocean don't mix due to density differences.

Explain why the geographic distribution of marine organisms is directly related to abiotic factors. Provide an example.

Abiotic factors are non-living chemical and physical factors in the environment, such as temperature, salinity, wave stress, and substrate type. Kelp forests are limited to rocky coasts with relatively cool water due to abiotic factors such as nutrient and sunlight availability. Kelp are large, fast-growing algae that require abundant nutrients and sunlight in order to photosynthesize and prosper. Therefore kelp are limited to coastal regions because it must be shallow enough for them remain in the photic zone their entire lives. Kelp also require a hard substrate to anchor themselves in the photic zone - without rocks to anchor their holdfast, kelp would be battered by the waves, float ashore and die. Kelp also require relatively cold water because they have high nutrient demands. Cold water tends to have higher nutrient levels - upwelling brings cold, nutrient-rich water up from the deep and cold currents bring nutrient-rich water from polar regions where there is less sunlight and therefore less photosynthesis consuming the nutrien

Why does symmetry matter? What does it tell us about evolutionary complexity?

Asymmetrical - lacking symmetry Radial- multiple planes of symmetry Bilateral - a clear single plane of symmetry. A clear head and tail

Why do we care about tissue layers?

Body cavities and organ systems! Body cavities are fluid-filled spaces that lie between cell layers. They evolved probably because they facilitate swift movement without crushing essential internal organs. The type of body cavity an animal has strongly influences how it can move. The pressure of the fluid and action of the surrounding muscles are used to change an organism's shape and produce movement, such as burrowing or swimming. The complete mesoderm lining allows organs to be attached to each other so that they can be suspended in a particular order while still being able to move freely within the cavity.

Both coral and kelp ecosystems are rich and diverse (have a lot of life as well as lot of variety of life). Why do so many animals live in and among kelp forests and coral reefs?

Both coral and kelp provide structure and abundant primary production for organisms living nearby. Primary production is important because it determines the total amount of energy available to organisms in the ecosystem - all consumers in the ecosystem rely upon the primary producers to capture the sun's energy in biologically available sugars. Ecosystems with a lot of primary productivity tend to have abundant life throughout all trophic levels because there is a lot of energy/food available. Structure is important because it provides a place for organisms to live and hide. Ecosystems with more complex structure tend to have more diverse communities because there is a lot of physical variation in the ecosystem - this means that there are lots of niches for different organisms to adapt to and live in. Also, many pelagic organisms come into both these ecosystems to birth and raise their young because they are safer than the open ocean. They are safer because the physical conditions tend to be milder - less wave action, etc. - and the structure provides places to hide from large predators.

List two specific examples of nutrients required for primary productivity. Why are nutrients essential for primary production if they are not listed as reactants in the photosynthesis equation? What do primary producers use nutrients for?

Both nitrogen and phosphorous limit 1° productivity in the ocean because they are components of essential biomolecules, such as DNA, RNA, proteins, and lipids. Primary producers convert the sun's energy into sugars, which power their cells, but they still need to construct their cells out of materials from their environment - these materials are chemicals that we refer to broadly as nutrients.

What are the primary nutrients that phytoplankton need to grow (you are only responsible for knowing the ones we discussed in class)?

Carbon, hydrogen, oxygen, nitrogen, phosphorous and sulfur are essential to the growth of organisms. In class, we discussed carbon, nitrogen, phosphorous and iron. Carbon is abundantly available for marine organisms. Inorganic nitrogen (N2) is abundant, but biologically available forms, such as nitrate (NO32-), nitrite (NO2-), and ammonia (NH3) are often limiting for marine photosynthesizers. Phosphorous, present principally as phosphate (PO43-) in seawater, is usually even more limiting than nitrate. Iron (Fe) is also an important, limiting nutrient in marine primary productivity.

What is Agnatha Class?

Class Agnatha (modern jawless fishes): Most similar to ancestral fishes Jawless Cylindrical bodies - no paired fins Have a partial cranium (skull), but no vertebrae Skeleton is made of cartilage Representative species include hagfish and lampreys:

Coral reefs

Coral reefs grow in clear water with low levels of nutrients. This limits reef-building corals to tropical coasts where the photic zone is deep.

Despite being very productive (high rates of primary productivity), coral reefs do not respond well to high nutrient loads resulting from coastal run-off or sewage outfalls. Explain why coral reefs do not just increase their productivity when nutrient levels rise.

Coral reefs struggle to compete with algae when nutrient levels rise. Corals have evolved to live in nutrient-poor waters, where algae struggle to survive, by hosting zooxanthellae in their tissues and providing them with nutrients. Corals continue doing this when nutrient levels rise, but algae can grow faster than the corals when they aren't nutrient-limited. The algae then grows over the corals and shades the zooxanthellae from the sun so that they can no longer photosynthesize. If this happens for too long, the corals usually die.

Deep-ocean (thermohaline) currents are driven by?

Density

Explain why there is zonation in coral reef ecosystems. Suggest coral adaptations that might be particularly beneficial in each major zone discussed in class.

Different coral species and morphological types prefer different habitats within a reef ecosystem based on varying degrees of wave energy, temperature, water chemistry and light resulting in zonation, or distributional patterns of corals on reefs. § The back reef is the zone found the closest to the shore. The shallow water in this part of the reef creates an area with high light intensity and temperature - an environment at the edge of coral tolerance. Due to the shallow depth of this zone, portions of back reefs can be exposed during low tides. The reef exposure along with higher temperature and light intensity inhibits coral growth. Despite these stressors, the corals in this region are protected from the majority of the wave stress that is present on the reef crest and upper fore reef. § The reef crest is found farther away from the shore and is between the back reef and the fore-reef. This is the area of the reef with the highest wave action and is therefore dominated by short, branching corals that are able to withstand moderate to high wave action. § The fore-reef is the reef zone that is the farthest away from the shore, on the oceanic side of the reef crest. It slopes downward at steep angles, sometimes to great depths. The fore-reef is home to the largest corals on the reef because it is the most hospitable environment with limited wave action. The corals are the most diverse on the reef slope between five and twenty meters of depth, and as depth increases coral species richness also decreases. The types of corals in this zone are most affected by light availability.

Explain what vertical zonation is in an ecosystem is and provide an example.

Ecological zonation is the distribution of organisms within an ecosystem resulting from abiotic and biotic gradients. For instance, zonation of rocky intertidal organisms results partly from adaptation to a gradient of physical conditions, such as air and water exposure, and partly from competitive and predatory interactions between the organisms. You should also provide a specific example to strengthen your response - for instance, sea stars and mussels.

What is Heat capacity?

Heat capacity is a measure of the heat required to raise the temperature of 1 gram of a substance by 1 degree C water= 1 cal/g C Water has a high heat capacity aka hard to change temp of water

Why does surface water sink at the poles?

It is cold and salty - therefore dense. It is cold because it is at the poles (away from the sun) and salty because the seawater leaves salt behind as it freezes into ice.

Kelp Forest

Kelp forests require cold water with high levels of nutrients. This limits kelp forest to rocky coasts where upwelling is common.

What do you need to know about water?

Key Ideas: - water is a very polar molecule - therefore very attracted to itself (strong IM attractions) - water has a high specific heat and therefore stabilizes both marine and terrestrial environment (b/c it takes huge inputs or removal of heat energy to change phase) - liquid at room temperature - exists in all three phases under normal conditions on Earth - solid water is less dense than liquid water - water is a good solvent to ionic salts. - seawater has a stable composition. - the most abundant gases in ocean water are N2, CO2, and O2 - high surface tension - high viscosity Water's unique chemical properties are responsible for the mild temperature conditions on Earth's surface and the very stable thermal conditions in most of the ocean.

What conditions are optimal for blooms of phytoplankton?

Marine primary productivity is usually either light or nutrient limited. Light is available at the sea surface (to varying degrees dependent on latitude) and nutrients tend to be concentrated in the deep water beneath the photic zone. Marine primary productivity is therefore limited to coastal areas (where nutrients runoff the land) and areas where upwelling and mixing occur and return the deep- water nutrients to the photic zone.

Explain how daily air temperature extremes would change if the Earth were entirely continental crust (no oceans).

More extreme - higher highs during the day and lower lows at night because the ocean has a higher specific heat than the substances that make up the land.

Is seawater temperature the same at all depths? Why or why not?

No, because the sun heats only the surface layers of the ocean - therefore the surface water is warmer than the deep water.

Is sea surface temperature the same at all latitudes? Why or why not?

No, because the sun heats the Earth unevenly - more at the equator and less at the poles.

What limits primary productivity in the ocean?

Nutrients and sunlight. Herbivores, which consume primary producers, also limit 1° productivity.

Why are nutrients abundant at depth?

Nutrients are abundant at depth because solid waste and dead organisms sink. Therefore decomposition, which returns nutrients to the water, mostly occurs beneath the photic zone and nutrients accumulate in the deep water where primary producers cannot utilize them. Stratification of the water column prevents diffusion of these nutrients back into the photic zone.

Where are nutrients abundant in the ocean?

Nutrients are usually limiting in the photic zone because of continual plant utilization. Nutrients are often more available in coastal zones due to runoff from land (pollution, fertilizer, and erosion) and are abundant in the deep layer, where photosynthesis does not occur due to the absence of light. Sinking detritus brings nutrients into the deep water and they remain there (until they are upwelled) because there is no photosynthesis to take them up and incorporate them into plant tissue.

Why are nutrients sometimes limited at the surface?

Nutrients may be limited in the photic zone because of continual utilization - the primary producers "use up" whatever nutrients are available.

oviparity vs viviparity

Oviparity: Lay egg Viviparity:give birth

Characteristics of Phylum Chordata?

Phylum Chordata Chordates have: organized tissues bilateral symmetry coelom (three tissue layers) PLUS 4 OTHER CHARACTERISTICS at some point in life cycle . . .dorsal notochord dorsal nerve cord pharyngeal pouches post-anal tail

Explain how nutrients such as nitrate or phosphate may limit primary productivity.

Plants require nutrients to grow and function - for instance, nitrogen and phosphorous are essential elements in DNA and proteins. Therefore, plants cannot photosynthesize and grow without these nutrients - when nutrient concentrations are low, then primary productivity slows or ceases.

Discuss kelp morphology and explain why it is well adapted for its environment.

Pneumatocysts are gas-filled floats that keep the kelp floating up near the surface, to maximize sun exposure. A strong, complicated holdfast helps kelp stay anchored to the rocky substrate - this keeps kelp in the shallow, coastal waters that are optimal for photosynthesis and prevents waves from washing it ashore. The stipes are strong but flexible which allow the kelp to withstand significant wave energy - the kelp move with the waves rather than stand rigidly against them. The blades are large and thin to maximize surface area for sun and nutrient absorption. The blades also tend to be flexible and broken into smaller pieces to minimize wave stress.

Why do pollutants, such as DDT, disproportionately impact top consumers (as compared to primary producers and primary consumers)?

Pollutants, such as DDT, biomagnify and therefore disproportionately impact top consumers. Biomagnification refers to the process whereby certain pollutants found in ecosystems are eaten by aquatic organisms such as fish, which in turn are eaten by large birds, animals or humans. The pollutant becomes concentrated in tissues or internal organs as they move up the food chain because it is very slowly metabolized or excreted (usually due to water-insolubility). Here is an example from Wikipedia to show how biomagnification works: A little fish eats plankton that has tiny amounts of mercury in it (from the water). That little fish eats a lot of plankton in its life and the mercury accumulates in its body. A bigger fish eats a lot of those little fish over its life, accumulating the mercury in each of those little fish into its body. At some point, all that mercury builds up and reaches toxic concentrations.

Define primary productivity.

Primary production is the production of organic compounds (sugars) from atmospheric or aquatic carbon dioxide. It may occur through the process of photosynthesis, using light as a source of energy, or chemosynthesis. Photosynthesis is responsible for most of the primary production on earth. All life on earth is directly or indirectly reliant on primary production.

What counter current Exchange?

blood and water flows in the opposite direction because it maintains a concentration gradient so equilibrium is not meet

What properties of seawater determine its density?

Salinity and temperature.

What is salinity?What processes affect seawater's salinity?

Salinity is saltiness, measure in parts per thousand. Evaporation, precipitation, runoff (from land) and hydrothermal vents affect salinity.

Differentiate between parasitism, commensalisms and mutualism and provide examples of each.

Symbiosis is a close ecological relationship between the individuals of two (or more) different species. Parasitism, commensalism, and mutualism are all types of symbiotic relationships. Both species benefit in a mutualism. Examples include: cleaner wrasse and cleaner shrimp eat parasites off fishes' skin; zooxanthellae and coral (discussed in question #9 detail below); the blind, tunnel-digging shrimp and sharp-eyed goby fish. In commensalism, one species benefits and the other is unaffected. Examples include: the fairy crab (Lauriea siagiani) lives in the large barrel sponge, camouflaged and hidden within the crevices of the sponge; remora fish travel everywhere with sharks and other cartilaginous fishes, eating scraps left over from their meals. In parasitism, one species benefits and the other is harmed. Examples include: worms living within the intestines of fish; the isopod that lives in the mouth of a fish, where it destroys the tongue and attaches itself to the remaining stub and the fish is actually able to utilize it as a replacement tongue to draw in and manipulate food, which the parasite shares.

Explain why killing sea otters threatens kelp forest ecosystems.Also explain why the California kelp forests remained relatively healthy for nearly 150 years after otters became functionally extinct.

Sea otters are keystone species, which means that they have a disproportionately large effect on their environment relative to their abundance. Sea otters protect kelp forests from damage by sea urchins because sea urchins eat the holdfasts of kelp - if there are too many urchins eating the holdfasts then the kelp is "uprooted" and the main structure and primary producer in the ecosystem floats away, destroying the ecosystem. Otters feed on urchins, keeping their population in check. California kelp forests remained relatively healthy years after otters became functionally extinct because there were still many large predatory fish in the ecosystem that also ate sea urchins. As otter numbers declined and urchins became more abundant, these predatory fish ate more urchins. But fishing has eliminated most of these fish from the kelp ecosystem so that now, even though the otter population has rebounded some, kelp forests are much more susceptible to urchin feeding frenzies.

Levels of Organization?

Some animals are only organized into cells. Others have advanced to the tissue level of organization or higher. As you study the different animal phyla, you will notice the evolution of more complex patterns.

Tissue Layers?

Some organisms have two kinds of tissues that develop in embryonic life. These tissues are the primary germ layers. If an animal has two germ layers as shown on the right it is said to be diploblastic. Some organisms have three kinds of tissues that develop in embryonic life. If an animal has three germ layers as shown on the right it is said to be triploblastic. Tribloblastic organisms are more complex than diploblastic organisms.

What are the important biological implications of this unique property?

Sorry this question is worded poorly - I'm asking why it matters that ice floats. It matters because it prevents whole bodies of water from freezing solid and killing all the little fishies. When water gets cold enough to freeze, the ice floats to the top and acts as insulation, protecting the water beneath it from freezing (because it is not exposed to the cold air).

Define stratification.

Stratification is the formation of distinct layers. The ocean is stratified by density - layers of different densities don't mix.

What forces and factors influence the direction of ocean currents? Write specifically about wind and the Coriolis effect.

Surface winds drive surface currents. The Earth's atmosphere is heated from the planet's surface, and enormous vertical cells (of air movement) are driven by differences in the amount of solar radiation reaching the surface at various latitudes. In general, areas of low pressure exist over the equatorial regions, and areas of high pressure exist over the polar regions due to a difference in temperature. Solar heating causes air to become less dense and rise in equatorial areas. This air is deflected northward and southward when it hits the top of the atmosphere. By the time it has traveled one-third of the distance from the equator to the North Pole, it cools and sinks in a belt-like area at about 30° latitude, creating an area of high pressure as it sinks toward the surface. Then it flows southward along the surface back toward the equator. Coriolis bends the flow to the right, thus creating the northeasterly trade winds that prevail from 30° latitude to the equator. Similar forces create circulation cells that encircle the Earth between 30° and 60° latitude, and between 60° and the poles. The Coriolis effect is the tendency for any object in motion to drift sideways from its course because of the Earth's rotation - in the Northern Hemisphere the deflection is to the right and in the Southern Hemisphere it is to the left. This happens because the Earth's surface is rotating eastward at greater speed near the equator than near the poles, since a point on the equator traces out a larger circle per day than a point on another latitude nearer either pole. The net result is prevailing winds as displayed in the diagram to the right.

Discuss the significance of an energy pyramid and explain how the size of a prey population limits the growth of a predator population.

The "ten percent rule" refers to the idea that at each transfer of energy through a trophic structure, only a small percent of the energy remains available for use by the organism in the next level up in the system. The majority of the energy is lost to the surroundings in forms such as heat. Trophic structure refers to what is often called the food chain or food web, wherein green plants (the producer level) capture energy from the sun through the process of photosynthesis and transform it into energy available to other living organisms (the consumer levels). The ten percent law suggests or implies that exactly 90% of the energy is lost in the transfer at each trophic level, and that only 10% is passed on as useable biological energy. Most of the energy available at one level in an ecosystem is lost in the transfer to the next level. A very small percentage of the light energy that reaches the leaf surface of plants is actually assimilated, or turned by photosynthesis into organic compounds. Most of the light energy absorbed by plants is converted directly to heat and lost. Many plant parts are inedible by herbivores (the next trophic level) and are lost for energy transfer. The plants use much of the energy absorbed to live, as do the herbivores that eat them. Energy lost at each level results in a pyramid of biomass: less energy available at the level of carnivores, for example, means less biomass at that level than at the level of herbivores. The growth and numbers of organisms in an ecosystem are closely (if not always directly) related to, and limited by, the amount of energy available, and that decreases markedly at each level of the food/energy system.

What factors contribute to the uneven heating of Earth by the sun? How is heat redistributed by the ocean from the tropical to the polar regions?

The Earth is heated unevenly by the sun because light loses some of its energy as it travels through the atmosphere. When the sun is directly overhead at the equator, light travels the shortest distance through the atmosphere before reaching the Earth's surface. At higher latitudes, the light has to travel through more atmosphere so more of its energy is absorbed or reflected before it reaches the Earth's surface. The ocean redistributes heat from the tropical to the polar regions with surface currents. Water has a high specific heat, so it takes huge changes in heat energy in order to change temperature - therefore tropical water holds its heat even as it moves away from the equator. For instance, the Gulf Stream distributes hot equatorial water up the coast of North America and all the way to Europe.

What is the deep layer?

The deep layer is all the water from the bottom of the thermocline to the seafloor - it is usually uniformly cold.

What is the deep layer?

The deep layer is the lowest layer in the ocean, existing from the thermocline to the seafloor. It is characterized by very stable temperature and salinity values.

What is the mixed layer? Why are temperatures constant within this layer?

The mixed layer is the uppermost layer in the water column. Turbulence (due to wind and wave mixing) homogenizes temperature and salinity characteristics in this layer.

Explain how the water column can become stratified.

The ocean is stratified by density because the ocean doesn't have uniform temperature and salinity. The mixed layer of the ocean tends to be warmer, and therefore less dense, due to solar heating. Temperature decreases with depth (as the water receives less heat from the sun) and is uniformly cold (~4°C) at depth. Salinity also varies throughout the ocean but in a less predictable fashion. That being said, the saltiest, coldest (and therefore most dense) water is generated at the poles and sinks to the deep ocean. Once a pycnocline develops, it is very difficult for vertical mixing to occur in the ocean.

Define the photic zone.

The photic zone is the zone of the water column in the ocean that is exposed to sufficient sunlight for photosynthesis to occur.

What happens to the salt in when seawater freezes?

The salt is left out of the ice crystals, making the remaining seawater even more saline (salty).

What is the thermocline?

The thermocline is a distinct layer of water in which temperature changes more rapidly with depth than it does in the layers above or below

What is the thermocline?

The thermocline is the layer of water between the mixed layer and the deep water, where water temperature decreases rapidly.

How is the ocean stratified by density? What physical factors are involved?

The water column is stratified density - less dense water floats to the surface and is separated from dense deep water by the pycnocline (area of rapid density change). Temperature and salinity are the major factors that determine the density of seawater. A thermocline (area of rapid temperature change) separates the warm, less dense surface layer from the cold, dense deep layer. The water above the thermocline is well mixed by the wind and therefore has uniform temperature and salinity. Below the thermocline, the water is isolated from the atmosphere so the temperature and salinity remain very stable. Besides the temperature, stratification can also be caused by differences is salinity. The transition zone is called a halocline for the salinity.

Explain how heat would be distributed across the globe if there were no continents.

There would be a band of hot water at the equator, a band of slightly cooler water at 30 degrees, a band of even cooler water at 60 degrees, and the coldest water at the poles . . . temperature would remain constant at a particular latitude.

What is Important about the Osteichthyes ?

Two types but Ray finned fishes are the dominated most abundant type Skeletons are calcified aka bone Harder and lighter (don't need fins to create buoyancy ) Have Swim Bladders bones and swim bladder reduce the need for fins to control buoyancy-- allows fins to evolve to perform other diverse functions

Describe how upwelling along the California coast returns nutrients to the photic zone.

Upwelling along the California coast occurs when winds coming from the Northwest drive surface waters offshore (due to Ekman transport and the Coriolis effect). As a result, cool, nutrient-rich water upwells from the deep towards the surface, replacing the warmer, usually nutrient-depleted surface water. These nutrient-rich waters are now in the photic zone, providing ample nutrients for a phytoplankton bloom (if light conditions are right).

What occasionally happens along the coast of California that mixes the water column and brings deep, nutrient rich water to the surface? How does this happen?

Upwelling is the process by which deep water is brought to the surface. Upwelling is most common where persistent wind blows parallel to a coastline. These winds drive surface water away from the coast (due to Ekman transport) and cold, deep water is pulled up from below to replace it. The upwelled water, besides being cooler, is richer in nutrients, so that regions of upwelling are generally also areas of high primary productivity and rich fisheries.

Explain how hydrogen bonding increases water's ability to moderate ocean temperatures.

Water is a very polar molecule, so IM attractions (H-bonding) make water "sticky." Therefore, it has a high boiling point - the ocean doesn't evaporate easily (it takes a lot of heat energy to change the phase from liquid to gas). IM attractions also contribute to water's high specific heat, which means it holds energy, distributing heat north and south of the equator. Water's polarity also means that water molecules freeze in a matrix, trapping air and making the solid less dense than the liquid - this helps moderate global temperatures because the surface ice insulates the deep ocean from the cold air at the poles, preventing more of the ocean from freezing.

Surface wind is driven by what?

Wind

Cephalization?

an evolutionary trend, whereby nervous tissue, over many generations, becomes concentrated toward one end of an organism. This process eventually produces a head region with sensory organs.

characteristics of Bilateral symmetry?

arises with evolution of a "brain" some sort central nervous system... more sophisticated senses and processing of surrounding. allows for more complex movement "cephalization"

Gills

fish breathe dissolved o2 in h2o water enters the mouth and exit their gills ALWAYS

What does a Swim Bladder do?

fish can control amount of gas in swim bladder to control buoyancy

Lateral Line?

its fishes 6th sense- - allows them to feel vibrations in the water around them - sense movement change in pressure

Diffusion

movement of particles from area of high concentration to area of low concentration

What is Chondrichthyes Class?

paired fins lack swim bladders have spiral valve intestines skeleton is made of cartilage have jaws with teeth (but jaws are only loosely attached) representative species include skates, rays, sharks, and chimeras:

How do fish swim?

propels fish forward with tail wave-like body motion why have fins on the top and bottom? to prevent pitch and roll pectorial fin -- fine motor control

Bilateral symmetry?

provides the basis for coordinated and directed movements, particularly toward food sources and away from predators. Environmental gradients (including food sources) can be sensed better by comparing the two sides of the bilateral body when using a CNS. Bilateral symmetry is correlated with development of sense organs and central nervous tissues at the anterior end of the body (cephalization).

What is Osteichthyes Class?

skeletons are calcified harder and lighter than the cartilage bones of the chondrichthyes great maneuverability and speed, highly specialized mouths equipped with protrusible jaws have swim bladders to control buoyancy The bony fish have evolved to be of almost every imaginable shape and size, and exploit most marine and freshwater habitats on earth. Many of them have complex, recently evolved physiologies, organs, and behaviors for dealing with their environment in a sophisticated manner.

What is the mixed layer? Why are temperatures constant within this layer?

the mixed layer is the top few hundred meters of water - temperatures are constant because wind and waves constantly mix this layer.

What is Important about the Chondrichthyes?

there skeleton is made of cartilage thats is VERY HEAVY. they need to compensate for it by having fatty liver etc because fat float also they have plane like fins to get lift they only look like sharks or rays

What happens to surface water at the poles?

they cool and sink

The trade wind push equatorial water...?

to the west

Why do the oceanic gyres flow the clockwise direction in the northern hemisphere and in a counterclockwise direction in the southern hemisphere?

urface winds and the Coriolis effect. In the Northern Hemisphere, strong trade winds that originate in the northeast and blow westward pull the surface of the ocean along with them near the equator. Thanks to the coastline and the Coriolis effect, the warm-water current then heads north at the western boundary of the ocean. At about 30 degrees north latitude, the westerlies take over and guide the current eastward. The current is deflected southward by the Coriolis effect and land when it hits the coast on the eastern boundary of the ocean basin. These wind patterns, combined with the position of the continents and the Coriolis force, create spiral ocean currents called gyres that flow clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere.