Benthic Organisms Sketches
Organism
Lichens
Sketch with details
Description and adaptations
Live above high tide line
Mutualism: two organisms living together
 Fungal component: thick outer surface to protect from
environment, absorbs 3 to 35 times its weight in water for
storage to be used later
 Algae: cells live in fungus and produce its own food to feed
itself and the fungal
http://razottoli.wordpress.com/lichen-zone/
Periwinkles
Single spiral shell that grows with their bodies, fleshy foot, short tail
and two antennae.
 Use food to hold onto rocks or marsh grasses
 Herbivores that breaks down food outside the body and then
consumes it
 Hermit crabs use the shells of dead periwinkles
 Retain moisture in gills for many days, close themselves into
their shell and excrete a sticky mucous that hardens, firmly
attaching the periwinkle to a surface.
 Adapt to extreme weather conditions
http://www.edc.uri.edu/restoration/html/gallery/invert/peri.htm
Barnacles
Can be found on whales, intertidal zones and subtidal zones
 Cluster together to reduce individual exposure to weather and
ocean waves
 Feed on the food the waves bring in
http://www.nhptv.org/natureworks/nwep6b.htm
Rock crab
Shell is yellow to red/orange with dark red on top. Underneath is
cream colored. Likes to live in rock environments and tide pools. Large
claws to chop food up, smaller feeding claws close to mouth, moves
slowly due to heavy front claws, eat worms, clams, mussels and other
invertebrates. Natural predators are: fish, crabs, gulls, and humans
 Flat smooth body to reduce powerful hit received from waves
 Hard shell for protection
 Antennae used for taste and smell, moveable eyestalks
 Females release hormone in water to attract a male, male
protect female during her molting season which is the only
time reproduction can happen
 Younger rock crabs live in shallower water, adult rock crabs
live in deeper waters
http://www.edc.uri.edu/restoration/html/gallery/invert/rock.htm
Snails
Blue
(common)
mussels
Hide under rocks, seaweeds and wet areas, they crawl slowly,
predators, dig into sand to find food, drill holes in shells to eat prey
 Drill holes to eat prey, foot becomes 4 times larger than shell
to cover more ground.
Found in sheltered locations, attaches to rocks, thin shell, can tolerate
a lot of silt so it can live in sheltered places such as bays and estuaries.
Blue black in color, bivalve, two equal halves, males and females
 Forms colonies or mussel beds km in size
 One strong food with a gland that makes a thread. This thread
clings together with millions of other mussels and to move
farther distances.
 Opens shell underwater only to breathe and eat food particles
 Filters 2 to 3 litres of sea water per hour (sewage water plants
of the sea)
 Females eject 5-12 million eggs into water, males fertilize
water
 Can tie down attackers with threads
http://dtc.pima.edu/blc/183/11_183/11_183answers.html
http://www.molluscs.at/bivalvia/index.html?/bivalvia/common_mussel.html
Red algae
Red in color, lives deeper than most algae and can still
photosynthesize because of absorbs blue light which penetrates water
deeper.
 Secrete a calcium carbonate onto surface to their cells
 Eaten by humans – dulse
http://www.seaweed.ie/algae/rhodophyta.php
Sea urchin
Lives in rocky shorelines, feed on microalgae and scrape algae from
rocks, reproduce in march to April, don’t like warm water
 Mouth located on its underside, anus is on its top
 Use long thin water filled tube feet and suction to move

Live under or near rocks, camouflage themselves by attaching
algae, rocks and undissolved material from decomposing dead
marine life to their spines.
http://www.geog.mcgill.ca/climatechange/ReportsMap/sea_urchinRpt.pdf
http://www.geog.mcgill.ca/climatechange/ReportsMap/sea_urchinRpt.pdf
Turban
snail
Smooth conical shell, brown, reproduce happens with females put
bright green eggs into the water and the males put milky sperm into
water.
 Picks up pebbles with the front of its foot and transfers them
to the back part, this changes its center of gravity, to help it
roll back over and right itself.
http://www.montereybayaquarium.org/animal-guide/invertebrates/brown-turban-snail
Video: https://www.youtube.com/watch?v=5jzD4SnM65w
Sea worm
Hermit
crab
Crustaceans, jointed limbs, claws, hard exoskeleton, eye stocks, two
sets of antennae. Stay together in larger groups, inhabits large snail
shell, shell stores water for crab, gills must remain moist in order to
breath, live in tide pools, move into larger shells as they grow
 5 pairs of legs and a pair of claws. One claw is much larger
than the others for defense and food shredding, smaller claws
are used for eating, the second and third pairs of legs help the
crab walk and the last two pairs hold the hermit crab in its
shell
http://www.montereybayaquarium.org/animal-guide/invertebrates/hermit-crab
Sand dollar
Invertebrate – Echinoderms, flat, burry themselves, filter feeders, use
small spines to each crustacean larva plankton and tiny prey. Food
passed from spine to spine until it reaches mouth at the middle of the
bottom side. Tube feet and spines help it move and tube feet take
oxygen from environment. Reproduce by broadcast spawning, almost
all skeleton
http://oceana.org/en/explore/marine-wildlife/sand-dollar
Clam
Mollusk common features: embryology (development of embryo from
fertilization), Radula (tongue for feeding with small teeth used for
scraping and cutting food), Nervous system, mantle (forms the outer
wall of the mollusk’s body and holds in the internal organs, it also
secretes calcium carbonate to form the mollusk’s shell.)
http://www.deceptionpassfoundation.org/wp-content/uploads/Intertidal-life.pdf
Brittle star
Echinoderms: Break off arms as a means of defense because new arms
grow back quickly, snake like movements, water-vascular system and
tube feet, walk with arms not tube feet, feed on detritus, small living
or dead animals, arms move food to mouth, complex jaw.
http://www.encyclopedia.com/topic/brittlestar.aspx
Star fish
Echinoderm: bony, calcified skin, camouflage colors or colors that
scare off predators, regenerate limbs, most organs in arms, consume
prey outside their bodies by using tiny tube feet to pry open clams or
oysters.
http://animals.nationalgeographic.com/animals/invertebrates/starfish/
Sea
Cucumber
Echinoderms: partially burry themselves, feed on tiny particles of
algae, aquatic animals and waste materials, tube feet break down
food into small bits before eating, fish eat them, to protect itself, it
discharges sticky threads to ensnare their enemies, mutilate body as
defense mechanism, they violently contract their muscles and excrete
internal organs which grow back quickly.
http://animals.nationalgeographic.com/animals/invertebrates/sea-cucumber/
https://www.crd.bc.ca/education/our-environment/ecosystems/coastal-marine/intertidal-zone
http://www.asnailsodyssey.com/LEARNABOUT/INDEX/author.php
http://www.cacaponinstitute.org/Benthics/BMI%20dich%20key.html