Marine Science-Chapter 16

Describe at least three animals that are commonly found in the Mesopelagic zone.

1. KRILL & COPEPODS - dominant, surface waters -kirll & most mesopelagic shrimps have an adaptation of PHOTOPHORES (light organs) specialized structure that produce light 2. MIDWATER FISHES -small (2-10 cm, 1-4 in) -bristlemouths/lanternfishes most abundant 3. OSTRACODS -group of crustaceans -Carapace (characteristic shell) -looks like tiny flames w/ legs -crustaceans (unrelated to clams) -small, few millimeters (1/8 in.) 4. ARROW WORMS -chaetognaths -important midwater predators 5. SQUIDS -swim weakly, are planktonic -have photophores

The mouth is also _______________________ with long _______________________ teeth.

1. LARGE 2. POINTED

Fish in this area are similar to those in the mesopelagic in _______________________, _______________________ , _______________________ .

1. Lack of swim bladders 2. Flabby watery muscles 3. Light weak skeletons

__________________, tiny animals that live among the sediment particles, are the most abundant organisms that live on the deep-sea floor. They ______________ on bacteria and absorb dissolved organic matter (DOM) from the water between the sediment grains.

1. MEIOFAUNA 2. GRAZE

Unlike the organisms in the _______________________ , the photophores are normally located near or on the head as opposed to on the _______________________ side.

1. MESOPELAGIC 2. VENTRAL

Days are spent in the _______________________ and nights are spent feeding in the _______________________ (especially plankton).

1. MESOPELAGIC 3. EPIPELAGIC

What are the FOUR DIVISONS of the deep sea in order?

1. Mesopelagic - 200 to 1000 meters 2. Bathypelagic - 1000 to 4000 meters 3. Abyssopelagic - 4000 to 6000 meters 4. Hadopelagic - 6000 to benthic community (can be as deep as 11,000 meters in trenches)

While food is limited in this environment. the amount of _______________________ in most areas due to exchange with surface waters via ocean currents like the _______________________ or _______________________ .

1. OXYGEN IS NOT LIMITED 2. GREAT OCEAN CONVEYOR 3. THERMOHALINE CIIRCULATION

The deep sea includes the _______________________________ zone, _________________________________ zone, and _______________________________ zone, which include the trenches.

1. BATHYPELAGIC (1,000-4,000 m or 3,300-13,000 ft) 2. ABYSSOPELAGIC (4,000-6,000 m or 13,000-20,000 ft) 3. HADOPELAGIC or HADAL PELAGIC ZONE (below 6,000 m to above sea floor [deep as 11,000 m or 36,000 ft]

These "_______________________ " vents and the cooler "_______________________ " support a WIDE variety of organisms besides bacteria such as fish, shrimp, tube worms, clams, crabs, snails, barnacles, sponges, corals, etc.

1. BLACK SMOKER 2. WHITE SMOKERS

Like fish in the epipelagic, these fish have _______________________ or _______________________ to escape notice from prey or predators.

1. COUNTERSHADING 2. TRANSPARENCY

Bioluminescence is thought to be used for _______________________ , _______________________ or _______________________ .

1. COURTSHIP 2. COMMUNICATION 3. PREY ATTRACTION

These bacteria are the _______________________ in the _______________________ in this unique community.

1. FIRST LINK 2. FOOD CHAIN

Describe two ways anglerfishes find mates?

1. PHEROMONES: males have powerful sense of smell which they use to locate a female. Females release special chemical that males can detect and follow 2. MALE PARASITISM: male locates bigger female, bites her side, remains attached for the rest of his life. This ensures male is always available to fertilize females eggs.

The presence of _______________________ on only the ventral surface results in a type of camouflage sometimes referred to as _______________________ .

1. PHOTOPHORES 2. COUNTERILLUMINATION

Deep-sea organisms also use bioluminescence, but not for counterillumination. The primary uses of bioluminescence are ______________________ __________________, _______________________________________, and courtship.

1. PREY ATTRACTION 2. COMMUNICATION

These communities share one important feature: the lack of ______________________________ ___________________________ of food produced by __________________________________.

1. PRIMARY PRODUCTION 2. PHOTOSYNTHESIS

Other organisms such as _______________________ , _______________________ and _______________________ can also be found in this area (deep sea benthos).

1. PTEROPODS 2. SNAILS 3. WORMS

They tend to _______________________ and have few _______________________.

1. REPRODUCE LATE IN LIFE 2. LARGE WELL DEVELOPED EGGS.

The main _______________________ (rapid temp. change? occurs in the _______________________ , so migrators must tolerate these changes. Change in _______________________ must also be tolerated as well.

1. THERMOCLINE 2. MESOPELAGIC 3. PRESSURE

Not only can they utilize this normally _______________________ substance, but they can withstand temps up to _______________________ .

1. TOXIN 2. 250 DEGREES F

Polychaete _______________________ are usually the most abundant macrofauna on the deep- sea floor, followed by _____________________________ and bivalve ___________________________.

1. WORMS 2. CRUSTACEANS 3. MOLLUSCS

The deep sea is the largest habitat on earth and contains about _______________ of our planet's liquid water.

75%

Many organisms are quite late compared to their counterparts in other marine communities (such as the _______________________ [are about the size of lady-bugs or smaller in other communities].

AMIPHIPOD

Food is scarce down in the ocean depths. What are the adaptations of midwater animals? Why are these features advantageous?

Adaptations -Feeding & food webs -vertical migration & deep scattering layer -sense organs -coloration & body shape -bioluminescence *small size *large mouths *hinged & extendible jaws *needle like teeth *unspecialized diets {MANY OF THE CHARACTERISTICS OF MIDWATER ANIMALS ARE DIRECTLY RELATED TO THE LACK OF FOOD IN THE MESOPELAGIC. ADAPTATION RESULT FROM LIMITED FOOD SUPPLY.} [MAY BE AN EVOLUTIONARY ADVANTAGE TO LIMITED GROWTH AND SMALL SIZE, HAVE WIDE RANGE OF PREY, BROAD DIET]

_______________________ (glowing light)- squids, plankton called copepods, jellyfishes, fishes)

BIOLUMINESCENCE

_______________________ is also common, via photophores or other specialized organs.

BIOLUMINESCENCE

What is bioluminescence? How does this adaptation help the animals in the mesopelagic zone?

BIOLUMINESCENCE: the production of light by living organisms helps mask silhouettes Bioluminescent photophores (found mostly on underside) produce light that breaks up the silhouettes and helps the animal blend in with the background light filtering down from the surface.

Angler fish possess a "lure" on the head that contains symbiotic _______________________ to attract prey.

BIOLUMINESCENT BACTERIA

Because the deep sea has lots of pressure, animals that live in this area have adapted to lose their swim _________________________, which causes them to reduce weight and to make them neutrally buoyant, allowing them to float at a constant depth without wasting energy swimming.

BLADDER

Animals from the deepest regions tent to have even smaller eyes or be ________________ altogether.

BLIND

_______________________ can be found in the deep sea sediments, but they decompose at a much slower rate than bacteria at the surface (as much at 1000 times slower.)

DECOMPSING BACTERIA

Below the mesopelagic there is no sunlight at all. This inky darkness is the world of the ______________ ____________. In addition, the water is cold with lots of pressure.

DEEP SEA

Due to the bacteria and meiofauna, _______________________ organisms are common.

DEPOSIT FEEDING

Bioluminescence is also present int he upper portions of the deep sea; however, the occurrence of this decreases with increasing _______________________ .

DEPTH

The mesopelagic lies just below the well lit _______________________ (twilight zone).

EPIPELAGIC

Life in the deep sea is reduced because it is primarily due to a reduction in the amount of _______________________ available.

FOOD

These wants may come and go as _______________________ in any given area may change.

GEOLOGIC ACTIVITY

In the deep sea, some animals tend to be larger than their shallow water counterparts. This phenomenon is known as deep-sea _____________________.

GIGANTISM

Oxygen in the deep sea is replenished by thermohaline circulation and the ____________________ ____________________ ________________ .

GREAT OCEAN CONVEYOR

The berths allows these organisms to have a _______________________ .

GREATER CHANCE AT FINDING FOOD

Not only do organisms tend to _______________________ but they also tend to grow slow and have an exceptionally long life.

GROW FASTER

Their _______________________ is modified to operate at low levels.

HEMOGLOBIN

Finding a mate in the deep-sea is also difficult so, many deep-sea fishes are ______________________________________________.

HERMAPHRODITES

Many other species are _______________________ - this strategy ensures that reproduction can occur if encounters occur between members of the same species (chemical cues, pheromones, help attract these fish together.)

HERMAPHRODITES

These vents contain large amounts of _______________________ that save as the energy source for these bacteria.

HYDROGEN SULFIDE

For unknown reasons, these types of strategies are not common in deep sea _______________________ .

INVERTEBRATES

The deepest known fish was recorded at a depth of 8,370 m. However, _______________________ like tubeworms have been found in the Mariana Trench (the deepest part of the ocean).

INVERTEBRATES

Many of mesopelagic fish _______________________ as adjusting the pressure in the swim bladder takes precious energy.

LACK A SWIM BLADDER

These fish normal have _______________________ eyes for seeing in the extremely low light conditions.

LARGE SENSITIVE

For as long as they last, the vents support a _______________________ of life not seen elsewhere in the deep sea.

LEVEL

Deep-sea animals grow slowly, however they also live a ____________________________.

LONG TIME

Species being hermapgrodites are important to an environment where the number of organisms is very _______________________ .

LOW

Another interesting adaptation is _______________________ .

MALE PARASITISM

In _______________________ (mating), a male angler fish (which are much smaller than the females) attach to the females and receive their nutrition from them and fertilize the eggs of the female.

MALE PARASITISM

Bacteria are not the only organisms in the sediments. A wide variety of _______________________ also live here.

MEIOFAUNA

Pressure resistant enzymes for _______________________ .

METABOLISM

_______________________ needed as no light is present.

NO COUNTERSHADING

There is an area call the _______________________ (OMZ) where oxygen levels are reduced due to greater degree of respiration in this area and lack of photosynthesis to replace the oxygen.

OXYGEN MINIMUM ZONE

Chemical attraction is also one way to attract the opposite sex. Such chemicals are called ____________________________________________.

PHEROMONES

The amount of of food in the deep sea is low due to the lack of _______________________ in this perpetually dark environment.

PHOTOSYNTHESIS

This is likely due to the extreme _______________________ present in the deep sea.

PRESSURE

__________________________________ seems to be a major factor causing zonation in deep-sea pelagic organisms.

PRESSURE

Many animals in mesopelagic are _______________________ (star fish, krill, crustaceans).

RED

Life in the deep sea is _______________________ compared to life in other marine communities.

REDUCED

One benefit of the benthos is that food that falls from above can become _______________________ .

TRAPPED ON THE BOTTOM

Interesting, one ground of these organisms- the _______________________- actually harbor the chemoautotrophic bacteria in their body to support their metabolic needs.

TUBE WORM

The mesopelagic zone is a world of __________________________________, which means that there is dim light during the day.

TWILIGHT

Instead of staying put and waiting for food, most mesopelagic organisms make _____________________________ _________________________________. The animals swim up at night to feed the rich layer and descend to the ocean depths during the day.

VERTICAL MIGRATIONS

Sue to this, many species that reside in the mesopelagic take part in _______________________ .

VERTICAL MIGRATIONS

What are three differences between vertical migrating and non-migrating fish?

VERTICAL MIGRATORS: 10 cm, swim bladder, well developed bones & muscles NON-MIGRATORS: 15 cm, no swim bladder, weak bones & flabby muscles

There are tubeworms that live in hydrothermal vents. How do they obtain food?

-Does not filter feed -Does not have a mouth or digestive tract -Specialized organ called trophosome *packed with symbiotic bacteria *bacteria performs chemosynthesis inside worms body and pass much of the organic matter they produce on to the worm *exchanging carbon dioxide, oxygen & hydrogen sulfide -Blood: special hemoglobin that chemical binds hydrogen sulfide, protecting worm from toxic effects, transport it to bacteria in feeding body

Adaptions of NON-MIGRATING mesopelagic fish

-Tend to have weak bones and flabby, watery muscles -This adaptation helps them neutrally buoyant and requires less energy -These fish also tend to be small (less energy required) -These fish normally have long sharp teeth and large jaws [this allows for them to feel on most any prey, even if the prey is larger than they are.]

Conditions in the Bathy-, Abyss-, and Hadopelagic

-The deep sea is the largest habitat and contains 75% of earth's water -Uniformly dark -Uniformly cold (about 35 degrees F) -Uniform salinity -Water chemistry is also relatively consistent

Hydrothermal vent communities

-These communities are an oasis in the otherwise nutrient poor deep sea -The chemical laden water escaping from cracks in the seafloor around the mid ocean ridges "feed" chemoautotrophic bacteria

Other animals of the mesopelagic

-Zooplankton such as krill and copepods as well as larger crustacean such as shrimp, ostracod, amphipods and isopods -Cephalopods such as octopus and squid are also found here

The eyes of these organisms are small or may be _______________________ or _______________________ (the eyes only used to detect bioluminescence.)

1. ABSENT 2. BLIND

In the epipelagic, the primary production is _______________________ and _______________________ and _______________________ abound.

1. ABUNDANT 2. PHYTOPLANKTON 3. ZOOPLANKTON

With no sunlight to support photosynthesis, the primary producers in hydrothermal vent communities are chemosynthetic ____________________________ and _____________________________.

1. ARCHAEA 2. BACTERIA

Deep-sea animals do not make vertical migrations, because the surface is too far and change of pressure is too great. How do animals like the anglerfish obtain food?

The first spine of their dorsal fin is modified into a long, movable "pole" that they wave in front of their mouths. Dangling from the end of the pole is the bait, a fleshy bit of tissue that resembles a tasty meal. Symbiotic bioluminescent bacteria live in the bait (glows in the dark). Gobbles down any unsuspecting victim. Only the females have a pole and bait.