Marine Animals

Terms to Know Plankton – lives floating in the water Nekton - lives swimming in the water Benthic - lives on the bottom of the ocean Sessile – lives attached to a surface

permanently

SessileBenthicNektonPlankton

Animals are often grouped are classifies according to the geometric symmetry of their bodies. Bilateral symmetry: body can be divided in

half by a single plane. The halves on each side of the plane are a near mirror image.

Radial symmetry: body parts are arranged around a central axis. Body can be split like a pizza into identical parts.

Kingdom – Animalia, Plantae, Fungi, Protista, Bacteria

Phylum Class

OrderFamilyGenus ▪Species

Human Classification:Kingdom: AnimaliaPhylum: ChordatesClass: MammaliaOrder: PrimatesFamily: HominidaeGenus: HomoSpecies: sapiens

Soft-bodied organisms without a backbone

Major phyla in order of increasing complexity

1. Porifera2. Cnidaria3. Worms 4. Mollusca5. Arthropoda6. Echinodermata

Most primitive animals Sessile (doesn’t move) and benthic

(lives on the bottom) Almost all are marine no true tissues, no organs Depend on currents for feeding

and sexual reproduction. No digestive, circulatory,

respiratory, or nervous system Examples: sponges

video

Contain stinging cells: nematocystsUsed to stun prey

Radially symmetrical (can be divided like a pizza and are equal)

Size range: microscopic to 20m (60 feet!)

Carnivorous: stun prey and use tentacles to move it to mouth

Two forms: polyp and medusaPolyp: sessile, mouth and tentacles

face upMedusa: plankton, mouth and

tentacles face down Simple digestive and nervous systems No circulatory, respiratory, and

excretory system Examples: corals, anemones, jellyfish,

hydra

video

Bilaterally symmetrical: two equal halves

Possess digestive and nervous systems (small brain)

Well formed tissues and organs Three phyla: Platyhelminthes Nematoda Annelida

Phylum: Platyhelminthes – flat worms Predators and

scavengers; some are parasites

Smaller than 3cm Lack excretory,

circulatory, and respiratory systems

reproduce asexually and sexually; individuals have both testes and ovaries.

Ex – flukes, tapeworms, marine flatworms

Phylum: Nematoda – round worms Complete digestive system

(mouth and anus) Reproduce sexually – distinct

male and female forms Present in almost all types of

environments Most are microscopic Some parasitic, w/o a host are

not Ex. hookworms

Phylum: Annelida – ring worms Bodies divided into segments Each segment can have its own

circulatory, respiratory, excretory, nervous, muscular and reproductive system

Ex. Earthworms, leeches, marine tubeworms and polychaetes

Have an external or internal shell Bilaterally symmetrical Well-developed nervous systems Flow-through digestive tract

Ex. Clams, chitons, squid, octopus, snails

Phylum: Mollusca: Three main classes:Gastropoda: “stomach foot”

Snails, conch, abalone1 External shell

Bivalvia: “two door”Clams, oysters, scallops2 External shells

Cephalopoda: “head foot”Squid, octopus Internal shell

Video

All are marine Radially symmetrical: based on five Larvae are bilaterally symmetric Lack eyes or brains Calcified endoskeleton covered by skin Water vascular system Reduced nervous and circulatory system (no

brain, no heart) Reproduce sexually Slow moving Benthic Regeneration of limbs, organs, or spines

Four familiar classes:Asteroidea: sea starsOphiuroidea: brittle starsEchinoidea: sea urchins, sand dollars

Holothuroidea: sea cucumbers

Video http://www.scivee.tv/node/2754

Contain a strong exoskeleton Striated muscle (quick movement) Articulation: can bend appendages Classes: crustacea (sea), insecta (land) Examples:

Lobster, crabs, krill, shrimp, crayfish, amphipods, barnacles, copepods

Largest phyla

Chordates – “back cord” All possess a nerve cord along the

back (ours = spinal cord) Vertebrates: possess a backbone One invertebrate group: tunicates or

sea squirts

Major groups:Fishes ReptiliaAmphibia Aves - BirdsMammalia

YES! Fishes – referring to

more than one species of fish Example: tuna and

bass = 2 fishes Fish – referring to

more than one of the same species Example: tuna and

tuna = 2 fish

Class: Agnatha jawless fish Hagfish and lampreys

Class: Chondrichthyes cartilaginous fish Skeleton made of

cartilage Skates, rays, and

sharks Class: Osteichthyes

bony fish Skeleton made of bone Majority of fish

Excellent eyesight Well developed hearing Lateral Line – organ along body

of fish to detect vibrations Coloration:

CamouflageCountershading

Relative termsDorsal – refers to anything on the backVentral – refers to anything on the

underside Fins

Pectoral – on side of fishAnal – rear of ventral side of fishPelvic – toward front of ventral sideDorsal – on the back of the fishCaudal – tail

MouthBony fish usually have a terminal mouth (front of the face)

Cartilaginous fish usually have a ventral mouth (under the face)

Mouth shape is particular to diet Gills

Along side of head, for breathingExtract dissolved oxygen from water

http://www.starfish.govt.nz/science/facts/fact-fish-chars.htm

Ex of amphibians: frogs, salamanders Require water to remove waste Salt water will cause them to

dehydrateb/c water will flow out of instead of into their skin

Therefore, none are marine Some Asian frogs can tolerate high

salinities for a period of time So… the answer is NO

Representatives in the ocean: turtles, snakes, lizards, and crocodiles

Ectothermic (cold-blooded)

Breathe air with lungs

Covered in scales Salt glands to

excrete salt Most live in

tropics to stay warm

Sea Turtles 8 species All endangered Green sea turtle

most abundant Marine crocodiles

Live in mangrove swamps and reefs

Hunt in packs Very aggressive Grow up to 2000

lbs and almost 23 ft long

Endothermic (warm blooded)

Thin, hollow bones Lightweight beak

instead of teeth Salt excreting glands Generally avoid

land, unless breeding

Four groups Tubenoses (albatrosses, petrels) Pelicans Gulls penguins

All mammals feed their young with milk

Three orders of marine mammalsCetacea: porpoises, dolphins, whales

Carnivora: seals, sea lions, walruses, sea otters

Sirenia: manatees, dugongs

Evolved from land mammals Streamline bodies Endothermic Modified respiratory system Osmotic adaptions

Skin impermeable to water No salt removal glands

Size range: 1.8m – 33m; up to 100,000kg

Forelimbs: used for steering Tail: horizontal for propulsion Thick layer of blubber

InsulationBuoyancy

Nostrils on top of head (blow hole)

Suborder: Odontoceti (Toothed whales)Use teeth to catch preySearch using echolocationEx: orca, dolphinsLargest: sperm whale

Suborder :Mysticeti (Baleen whales)Have no teethUse a baleen to filter out food (sort of like brushes or bristles)Eat krillEx: humpback whales, blue

whale

Suborder : Pinnipedia (wing foot) Seals, sea lions, and

walrusesLeave the ocean to

mate and raise young Suborder : Fissipedia

(split foot)Sea otters, polar

bears (also dogs and cats, although they’re not marine)

Only herbivorous marine mammals

Graze on sea grass, marine algae, and marsh plants

Slow moving, lethargic, small brains

Manatee, dugong