OCN 201 Biology Lecture 7

Marine AnimalsII. The Chordates

The Animal Family Tree

Ancestral Protist

Round Worms

Mollusks

Segmented Worms

Arthropods

Chordates

Echinoderms

Cnidarians

Ctenophores

Sponges

Flatworms

Placozoa

anus firstmouth first

Sea Stars

Brittle Stars

Sea Cucumbers

Sea Urchins

Crinoids

Echinoderms

Looks like radial symmetry, but is not really

Echinoderm Larva

Bilateral symmetry

Bilateral symmetry echinoderms is more obvious in the larval stages

Round Worms

Mollusks

Segmented Worms

Arthropods

Chordates

Echinoderms

Cnidarians

Ctenophores

Sponges

Flatworms

Placozoa

The Animal Family Tree

Ancestral Protist

Chordate TreeInvertebrates Vertebrates

Chordate Features

Chordate Features

Chordate TreeInvertebrates Vertebrates

• Pelagic or benthic

• Often colonial

• Suspension feeders

TunicatesSalps

Larvaceans

Ascidians(sea squirts)

• Small fish-like, No Jaw• Suspension feeder• Can swim, but usually stays partly buried

Lancelets

Amphioxus

Chordate PhylogenyInvertebrates Vertebrates

• Jawless fishes (Agnatha)

• Cartilaginous fishes (Chondrichthyes)

• Bony fishes (Osteichthyes)

The Major Fish Groups

Jawless Fish

• No jaws

• No appendages

• Cartilaginous

• Parasites or Scavengers

Lamprey

Hagfish

(Parasite)

(Scavenger)

Jawless FishHagfish slime defense

• Sharks, Skates and Rays

• Skeleton of cartilage

• Have jaws

• Carnivores or Planktivores

Cartilaginous Fish(Chondrichthyes)

• Planktivores (filter feeders) are largest

• Gaping mouth with small or no teeth

• Gill rakers

• Manta Ray (8 m across!)

• Whale Shark (up to 17 m long!)

Cartilaginous Fish: Planktivores

Gill Rakers

Manta Ray

PlanktivoresWhale Shark

Cartilaginous Fish: Carnivores

Cookie-Cutter SharkPhoto: NOAA

Cookie-Cutter Shark Wounds

Goblin Shark

Photo: Mike Spalding vis WIRED magazine

• 22,000 species

• From about <1 cm to 11 m

• Surface to ≥ 8370 m deep

Bony Fish (Osteichtyes)

Oarfish

Stout Infantfish

Herbivores

Herbivores (algae)

mouthfilter:gill rakers

gill opening

H2O

gut

Used by the most successful groups

AnchoviesSardines

Planktivores (Filter Feeders)

CarnivoresParrot Fish

Tuna

Mola molaUp to 1300 kg and 3 m tip to tip

Most Massive bony fish:

Feeds on gelatinous zooplankton

Reptiles, Birds, and Mammals

• Loggerhead

• Leatherback

• Hawksbill

• Olive Ridley

• Green Sea Turtle (Honu)

Sea TurtlesLARGEST:

> 2 m long up to 1300 lbswww.conserveturtles.org

• Crocodile - one living marine species

• Snake - 50 species

Other Marine ReptilesTropical West pacific/Indian Ocean

Marine Birds

• albatross, shearwaters

• gulls and terns

• pelicans, cormorants, frigate birds

• penguins

Mammals

• Endotherms (warm-blooded) • Breathe Air • Have Hair • Live Young • Milk Production in Females

Features:

Marine Mammals (Class Mammalia)

Carnivora - polar bears, sea otter, pinnipeds

Sirenians - dugongs and manatees

Cetaceans - whales and dolphins

CARNIVORA

Enhydra lutris

Sea Otters

Ursus maritimus

Polar Bears

Pinnipeds (seals and sea lions)

Sirenians

• dugongs and manatees

• Herbivores - eat sea grasses

• Near shore inhabitants of warm tropical waters

• About 13,000 alive today - recently taken off the endangered species list

Cetaceans

Includes the whales, dolphins and porpoises

Two Cetacean Suborders:• Mysticetes (11 living species)

– large – baleen whales - filter feeders – 2 blowhole openings

• Odontocetes (about 67 species) – smaller – toothed whales, dolphins, and porpoises – 1 blowhole opening

Mysticetes(baleen whales)

Use complex vocalizations or “songs” for communication

Baleen (Mysticetes)

• Large mouthfuls of water are filtered through the baleen plates trapping plankton, small fish and other animals

Humpback Bubble Net

Mysticete Migration patterns

• Great whales migrate:

- Warm, tropical waters in the winter (for breeding)

- Colder, polar waters in winter (for feeding)

Humpback WhaleHumpbacks around Hawaii(Mid-December to May)

Odontocetes(toothed whales)

Use squeals chirps and clicks for communication, echolocation and

stunning of prey

Carnivores