BIOS 104: Animal Diversity Laboratory

Kingdom Animalia - multicellular aerobic heterotrophs

• Most form tissues (all except Porifera)
• Most are diploid
• Most are motile

Ways to organize animal diversity

• No orgaized tissue vs organized tissue
• Two Tissue Types (Diploblastic) vs Three Tissue Types (Triploblastic)
• Radial Symmetry vs Bilateral Symmetry
• Body Cavity Type: Acoelomate vs Psuedocoeloma te vs Coelomate
  • Protostomes vs Deuterostomes

What is a tissue?

• A tissue is a group of cells which work together for in a particular function

Tissue types

• Endoderm - the innermost tissue - forms the digestive tract
• Mesoderm - the middle tissue - forms the musculature, blood, bone, reproductive
• Ectoderm - the outermost tissue - forms the skin, nervous tissue, sensory organs

Animal Diversity

Phylum Porifera - sponges - animals with no tissues and no symmetry

• There are different cell types in a sponge, each cell with different functions, but they are not a tightly integrated system like in other animals - you could stick a sponge in a blender and the sponge would reform
• Primarily filter feeders -
• Collar cells with flagella beat, pulling in water and food
• Influx passes through the matrix, where amoebocytes and collar cells absorb food
• Structure maintained by spicules

Phylum Cnidaria - radially symmetrical animals with only two tissue types

Examples: corals, jellyfish, hydra

braincoral	jellyfish	hydra

• Endoderm - forms digestive tract
• Ectoderm - forms epidermis
• Mesoglea - jelly-like acellular substance between tissues (the "jelly" in jellyfish)
• Not a true tissue
• Radially symmetrical
• First organisms with a nervous system - not centralized (no brain)
• Incomplete digestive tract
• Possess nematocysts - stingers - unique character in group
• Use to stun food for predaceous types

• The triploblastic organisms have three unique ways to organize their tissues - these are based upon the formation and arrangement of an internal, fluid-filled cavity. A fluid-filled cavity is very structurally diverse (for both flexibility and support) structure.
• The fluid-filled cavity is known as a coelom (pronounced see-lom)
• Allows for support (hydrostatic skeleton), protection from shock (important if an organism is going to become larger), movement (differential pressures create movement)

Examples: planarians, flukes, tapeworms

acoelomate usually internal parasites or free living organisms incomplete digestive tract flatworms are structurally limited by not having a fluid-filled cavity

Examples: roundworms, rotifers

		psuedocoelomate usually internal parasites complete digestive tract (possess both mouth and anus) separate sexes possess lateral muscles - can only move side to side (cannot manipulate coelomic fluid)
rotifer	nematode

Examples: snails, clams, octopus

• coelomates
• Mantle tissue - secretes shell
• radula (chitinous tongue - used like a rasp)
• advanced sensor organs & nervous tissue

Class Gastropoda - snails & slugs Usually have a coiled shell Extremely diverse Slugs = terrestrial gastropod which has lost shell

Octapus vulgaris	Loligo forbesi	Nautilus sp.

• Loss of shell (in all but Nautilus)
• Most advanced nervous system and sensory organs of any invertebrate

Class Bivalva - clams, oysters Two shells which can open and close Aquatic

Phylum Annelida - segmented worms

Examples: earthworms, leeches, polychetes

	coelomate Ventral nerve cord Two types of muscles - longitudinal & circular Full utilization of coelom in movement, support
polychete worm

Phylum Arthropoda - arthropods

Examples: scorpions, spiders, insects

• coelomate
• Hardened chitinous exoskeleton
• Specialized segmentation
• Jointed appendages
• Specialized respiratory organs (fully terrestrial)
• Division of labor in life cycle

Subphylum Chelicerata - Chelicerates

• specialized hollow mouth appendages
• usually used for delivering venom or other toxins to prey

Tarantula sp.	Scorpion

Subphylum Mandibulata - Mandibulates

• have mandibles (solid mouth organs)

There are many groups of mandibulates. We will only be looking at two.

hermit crab	shrimp

• Class Crustacea - aquatic, all have gills
• Examples: crabs, lobster, barnacles, pillbugs
• aquatic
• all have gills (even terrestrial ones like the rolly-polly)

sulfur moth	honey bee
cockroach	preying mantis

• Class Insecta - most diverse group on the earth
• Examples: ants, bees, butterflies, silverfish, roaches
• Body parts in three segments
• Most have wings & advanced sensory organs
• Advanced communication, social structure

Review the Protostome and Deuterostome devekopmental patterns of tissue development

	Protostome - spiral, determinate Mesoderm split to form coelom Mouth from blastopore Examples: mollusks, annelids, arthropods (all celomic groups from last lecture)
	Deuterostome - radial, indeterminate Mesoderm an outpocketing from endoderm - gap forms coelom Anus from blastopore Examples: echinoderms, vertebrates

Phylum Echinodermata

Examples: sea urchins, starfish, sea cucumbers

sea cucumber	starfish	sea urchin

• Water vascular system - system unique to this phylum
• Functions in movement, support, respiration, digestion
• Decentralized nervous system
• Rapid regeneration
• Secondary radial symmetry
• Larvae are bilaterally symmetrical
• Adults are radially symmetrical

A tube foot, an extension of the water vascular system of a starfish. The tube feet act like little suction cups which enable to starfish to grasp onto the sediment for movement or to break into bivalves for food. Note that since this is not a muscular system, they will not tire.

Phylum Chordata

Examples: Sea squirts, lancelets, vertebrates

• Notochord
• Pharyngeal Gill Slits
• Dorsal Hollow Nerve Cord
• Post Anal Tail

Subphylum Urochordata - the sea squirts larval stage possesses all of the chordate characteristics most of these characteristics are lost when the larvae undergo metamorphosis and emerge as adults adult stage are primarily sessile filter-feeders

Subphylum Cephalochordata - the lancelets possesses all of the chordate characteristics throughout life cycle burrow into sand and use mucous-secreting organs to filter-feed are feeble swimmers

Subphylum Vertebrata

BONE - reduction of notochord (vertebral disks)

Class Agnatha - the jawless fish (not monophyletic) Examples: lamprey, hagfish no jaws most are parasitic fish very diverse group in past. Now, only a few species are still hanging on

sand tiger shark	stingray

Class Chondrichthyes - the cartilaginous fish (monophyletic ??)

Examples: sharks, rays, skates

• endoskeleton is composed entirely of cartilage
• heterocercal caudal fin
• two-chambered heart
• numerous rows of teeth
• internal fertilization and separate sexes

Class Osteichthyes - bony fish (not monophyletic)

Examples: marlin, bass, catfish, anglefish, eels

scaley head	sea horse

wolf eel	stickleback

• most diverse group of vertebrates
• paired fins with fin rays of cartilage or bone.
• Respiration by gills supported by bony gill arches and covered by a common operculum.
• Swim bladder often present.
• Two-chambered heart.
• Sexes separate and fertilization is usually external.
  • Ray-finned fish - most fish possess this fin structure
  • Lobe-finned fish - lung fish, Coelacanth, etc.
  • the lobe-finned fish gave rise to tetrapods

Class Amphibia - amphibians (not monophyletic) Examples: frogs, salamanders Living skin - must be moist to breathe Lay eggs in water Outcompeted in water (fish) and land (reptiles)

Class Reptilia - reptiles (not monophyletic) Examples: lizards, snakes, gators first truly terrestrial animals Amniotic egg Scales (lungs now sole respiratory organ) Modificatons of pectoral and pelvic girdles to facilitate movement on land

Class Aves - birds (monophyletic) Examples: robin, jays, emu Feathers warm-blooded (high metabolic rate) hollow bones

Class Mammalia - mammals (monophyletic)

Examples: elephant, bats, Al Gore

vampire bat	deer mouse	elephant

• Hair
• mammary glands
• occlusional teeth
• warm-blooded (high metabolic rate)

Click here to view a diagram of animal phylogeny