Study Guide for Module 12 Flashcards
Benthos
Marine organisms that live on the sea bottom
Nekton
Marine organisms that swim strongly enough to move against the ocean current
Plankton
Marine organisms that cannot swim strongly enough to move against the ocean current
Meiofauna
Microscopic invertebrates living within the interstitial spaces of aquatic soil
Sand dollar
Benthos
Larval fish
Plankton
Shark
Nekton
Jellyfish
Plankton
Crab
Benthos
Why is the continental shelf also called “subtidal”?
It stays underwater regardless of the tides
How does wave action determine the types of substrate particles present in a shelf environment?
Heavey wave action washes away fine particles and leaves mainly sand. Areas without much wave action, or those protected from it, have fine sediments
What are the 3 types of organisms that make up benthos?
Infauanal organisms, epifaunal organisms, meiofaunal organisms
Which type of soft substrate contains little oxygen and lots of organic matter?
A muddy bottom substrate
Which type of community has a larger number of species living in it: a soft-bottom estuary or a soft bottom shelf community?
Soft-bottom self communities
Are the infauna evenly distributed throughout the substrate in a soft-bottom subtidal community?
The infauna are not evenly spaced in the substrate of soft-bottom salt communities
What is the major food source of the unvegetated soft-bottom self communities?
Detritus
What does scuba stand for?
Self-contained underwater breathing apparatus
You are studying a shelf community with a snandy-bottom substrate. What type of feeding mechanism would you expect most of the organisms living there to use?
Most organisms in a sandy bottom shelf community will use suspension feeding
What makes meiofauna different from the infauna in a substrate?
Meiofauna are small enough to fit between the individual particles of the substrate
A student tells you he observed a soft-bottom community in which suspension feeders and deposit feeders were roughly equal in number and lived in close proximity to one another. Why should you be skeptical of this student’s report?
Suspension feeders do not live near deposit feeders because deposit feeders churn through the sediment looking for food. It’s also rare to find them in equal numbers
What kind of seagrass do you typically find in the tropics? What kind do you typically find in temperature regions?
In the tropics, turtle grass is most commonly found, while in temperature areas eelgrass is more common
Seagrasses do not provide much live plant food to organisms living in the community. How does their tremendous primary productivity get into the food chain, and what other benefits do they provide for their community?
Many organisms feed on the decaying seagrasses, Seagrasses roots aid in keeping soft substrate more stable, seagrass blades provide shelter for many creatures, and the blades are locations on which algae and organisms directly dwell
Name at least 2 organisms that feed directly on live seagrasses
Manatees, nudibranchs, sea urchins, sea turtles, and a few species of bird, like Canadian geese
What type of organisms dominates the hard bottom shelf communities: infauna or epifauna? Why?
Epifauna, this is because there is little soft substrate into which infauna can bury
Why are seaweeds so common in hard-bottom shelf communities and not in soft-bottom shelf communities?
Seaweeds need a hard surface onto which they can hold because they do not have roots that can anchor them to a soft substrate
What factors keep most animals from grazing on seaweed?
Having special chemicals that give them a bad flavor, some are leather-like, and others incorporate calcium carbonate into their tissues to give them a hard-shelled outer surface
What are some of the environmental requirements necessary for kelp growth?
Sunlight; a hard substrate on which to attach; and cold, nutrient-rich water in order to grow
What is the difference between a kelp bed and a kelp forest?
A Kelp bed has kelp that is not tall enough to reach the surface of the water. While kelp forest is composed of kelp that grows all the way to the surface forming a canopy of the surface
Which has more chromosomes, the cells of the gametophyte generation of kelp or the cells of the sporophyte generation of kelp?
The cells of the sporophyte generations
A professor tells you that you are looking at full-grown giant kelp. However, you are looking at it with a microscope, and you can see the entire organism. How can the professor be correct?
You are looking at an individual from the gametophyte generation of giant kelp
Brittle Starfish
Holdfasts and kelp
Octopuses
Substrate between kelp
Fishes
Up in the water column on the blades of kelp
Small sessile suspension feeders
Directly on the kelp strips and blades
Explain why, during a sea urchin explosion, kelp plants are so easily killed off yet are rarely completely eaten
During a sea-urchin population explosion, there is not enough drift kelp on which to feed. So sea urchins crawl along the bottom and eat holdfasts of the kelp
What are benthos organisms? Give an example
Benthos - marine organisms that live on the sea bottom (star fish, sea urchin)
What are Nekton organisms? Give an example
Nekton - Marine organisms that swim strongly enough to move against the ocean current (Tuna)
What are Plankton organisms? Give an example
Plankton - Marine organisms that cannot swim strongly enough to move against the ocean current (planula larvae, jellyfish)
What determines the size of the particle in the substrate of a shelf community?
Wave action
What is meiofauna?
Meiofauna are microscopic organisms that live between the sediment particles
What is infauna?
Infauna are organisms that burrow into the substrate
What is epifauna?
Epifauna are organisms that live on top of the substrate
What type of infauna live in sandy substrates
Filter feeders
What types of infauna live in muddy substrates?
Deposit feeders
Why do deposit feeders and filter feeders generally not live together?
Deposit feeders stir up the sediment which can clog the filter of filter feeders
What provides the primary productivity of the vegetated soft-bottom community?
Seagrasses
What are all the methods that the kelp plant has at its disposal to avoid getting eaten
- Thick leathery leaves
- A chemical that makes them taste bad
- Some incorporate calcium carbonate into their tissues that give them a hard shell surface
What are 3 conditions necessary for kelp growth?
- Coldwater, nutrient-rich water
- Hard substrate
- Sunlight
How does a kelp bed become a kelp forest?
The kelp will grow long enough to reach the surface and float, creating a canopy in the way that a rain forest does
Sea urchins prefer to eat the floating kelp blades that have come loose from the kelp. If they are not able to find that, what else will they eat?
As they crawl along the bottom they will encounter the holdfast of other kelp and will eat that
