The Benthic Environment

Question 1

Porifera (Phylum)

Answer 1

Sponges
Each of the cells that make up a sponge work independently.
Each cell “eats” its own food and works to digest it
Sponges are filter feeders
ALL sponges are carnivores
Can live up to 200 years and can be quite large (largest was 10 ft)
Reproduce sexually
Great water filters, filter up to 50,000x their own volume PER DAY!

Question 2

Cnidaria (Phylum)

Answer 2

Coral, sea anemones, siphonophores (jellyfish)
About 11,000 species
Diverse phylum, common in their possession of stinging tentacles
Two basic life forms:
- Medusa (mobile)
- Polyp (immobile)
Some live as just one form, others live as both
Large food source for fish, sea turtles, sea slugs, and starfish

Question 3

Platyhelminthes (Phylum)

Answer 3

Flatworms, tapeworms, flukes

Question 4

Nematoda (Phylum)

Answer 4

Roundworms

Question 5

Annelida (Phylum)

Answer 5

Segmented worms

Question 6

Mollusca (Phylum)

Answer 6

Chitons, snails, bivalves
Have over 50,000 species
Largest MARINE phylum
Include gastropods, bivalves, and cephalopods (squid, octopus, etc.)
ALL have well developed body organs but lack body segmentation
Oysters are capable of filtering 50 gal. of water a day
ALL have:
1. Bilateral symmetry
2. Muscular FOOT
3. Mantle
MOST have:
* Radula - A tongue like ribbon of small teeth, used for feeding
* Shell
* Tentacles, evolved from FOOT
* Highly developed nervous system

Question 7

Arthropoda (Phylum)

Answer 7

Crabs, shrimp, barnacles
Over 1,000,000
Largest phylum of life on EARTH
Crustaceans have a exoskeleton made of chitin, as they grow they molt
Most are scavengers or filter feeders
Important source of food for many animals

Question 8

Echinodermata (Phylum)

Answer 8

Sea stars, urchins, sea cucumbers
Contains over 6,000 species
HAve the ability to regenerate lost body parts
Do not have blood or a heart, use a water system (like veins but with H2O instead of blood) to get oxygen
Do not have eyes
Some eject their stomachs to feed

Question 9

Chordata (Phylum)

Answer 9

Fish, tunicates

Question 10

Sandy Shore Community

Answer 10

Sandy beaches are common throughout the world
Most important factors impacting these environments are:
* Particle size - Coarse sand allows much more water to drain through, while fine sand holds water and is better for burrowing
* Wave action - Controls erosion and sand movement
* Slope - Controls the degree of erosion, and sand movement

Question 11

Rocky Shore Community

Answer 11

Not as common as sandy shore
One of the best studied marine ecosystems (organisms cannot hide in sand)
Variety of algae thrive
Barnacles, mussels, and oysters are the dominant species
Tidal pools often occur,

Question 12

Organisms in Tidal Pools

Answer 12

Factors that influence organisms in tidal pools:
* Temp. - Tidal pools are shallow, which can allow for extreme temperature shifts
* Salinity - Evaporation of water leads to an increase in salinity
* Oxygen - Dissolved O2 increases as organisms respire

Question 13

Sea Grass Community

Answer 13

One of the most productive marine ecosystems
Found in shallow waters
Important for oxygen and stabilizing ocean floor with roots
Can absorb carbon up to 35x faster than the Amazon Rainforest
Supports over 1,000,000 marine species

Question 14

Kelp Forests

Answer 14

Found in colder temperate regions
Kelp grow extremely fast
Many organisms can find shelter and food here
Does not have roots