Metazoa Flashcards
Learn vocabulary and concepts associated with metazoa
Gills
External organ that enables most aquatic animals to take dissolved oxygen from the water
Lungs
A pair of organs in the body that supplies the body with oxygen
Internal Fertilization
Type of reproduction in which the sperm is delivered by insemination within the body of the female
External Fertilization
Type of reproduction in which the sperm of the male fertilizes the egg outside the female’s body
Usually requires body of water
Symbiosis
Interaction between two different organisms living in close physical association
Coevolution
Influence of closely associated species on each other in their evolution
EX: Plants and pollinators
Morphological Stasis
A phenomenon that has to do with the absence or little morphological change over a long period of time
EX: Horseshoe crab
Squat vs stalked body forms
Squat:
Adv - more protection
Dis - less mobility, less access to food, more crowding
Stalk:
Adv - less space, more accessibility
Dis - more vulnerable, breakage
Mantle
The organ that forms the shell and adds to the shell size and strength through secretion
Foot
Musculature used to locomotion
MODIF: Specialized foot in Bivalves used in digging, grasping, or creeping; Cephalopod foot is arms/tentacles
Radula
The organ for mechanical food processing in mouth
BIVALVES HAVE NO RADULA
Shell
Large hard covering that encloses soft body parts
MODIF: Chiton have shell plates; Gastropod have torsion
some mollusca lost shell like sea slug and cephalopod
Torsion
A process which the mantle, mantle cavity, and visceral mass are rotated 180 placing the anus above the mouth in Gastropods
Blastula
The hollow ball of cells formed from the zygote dividing mitotically
Gastrula
Two-layered stage through the movement of cells and folding of layers of the blastula
Ectoderm
The outer layers of the gastrula
Endoderm
The inner layers of the gastrula
Mesoderm
Third tissue layer (triploblastic) which forms in two ways
Source of most organs and systems in body
Blastopore
Opening into sac-like cavity (becomes gut) that either becomes mouth or anus
Complete gut
One-way gut that has two openings and food moves in same direction
EX: Ctenophora, Bilateria
Incomplete gut
Two-way gut that only has one opening (sac-like) that is the mouth
EX: Cnidarians
Acoelomate
Animals that have no internal, fluid filled body cavity separating body wall from digestive tract
Pseudocoelomate
Animals that have a pseudocoelom which is not completely lined by mesoderm
Coelomate
Animals that have a coelom that is completely lined by mesoderm
Radial
Many planes of symmetry
EX: Cnidaria
Pentaradial
5-part symmetry
EX: Echinodermata
Bilateral
One plane of symmetry
Associated with segmentation and increased sensory and locomotor ability
EX: Chordata, Mollusca, Annelida, Nematoda, Arthropoda
Asymmetrical
No planes of symmetry
EX: Porifera, Ctenophora
Spicules
Strucutral component of sponges
Trocophore Larvae
A type of marine plantonic larva present in the clade Lophotrochozoa
Choanocytes (collar cells)
Special flagellates cells move the water and capture food in sponges
Cnidocytes
Specialized stinging cells within the phylum Cnidaria
Nematocysts
Specialized cell in the tentacles of jellyfish containing a barbed or venomous coiled thread that can be projected
Polyp
Anenome body form of a Cnidarian
Medusa
Jelly body form of a Cnidarian
not present in most anthozoa
Ctenidia
The gill of a mollusk consisting typically of a respiratory structure
Setae
Brustles on body of annedlida that are for movement
Clitellum
A raised band encircling the body of Annelida made up of reproductive segments
Segmentation
Division of some animal and plant body plans into repetitive segments
Cephalization
The presence of a concentration of nerve and sensory structures at one end of the body
Tagmata
Fusion of segments into specialized body regions
Chelicerae
A pair of appendages in the mouth of arthropods
(Pincers)
Ecdysis
Moulting of the cuticle of the exoskeleton
Tube feet
Echinoderms use for water vascular system and movement
Water vascular system
Echinoderms use for locomotion and feeding
(Utilizes the movement of water)
Notochord
Embryonic midline structure common to all chordata
Provides mechanical purpose
Supports dorsal (rigid yet flexible)
Pharyngeal slits
Function in respiration and feeding: water comes in mouth leaves through slits
NOT A SYNAPOMORHY OF CHORDATA IN OTHER DEUTEROSTOMES
Dorsal hollow nerve cord
Derives from ectoderm that rolls into the tube during development
Develops into central nervous system
Post-anal tail
Posterior elongation of the body extending beyond anus
Contains skeletal elements and muscles
Purpose of propulsion and locomotion
Porifera
Asymmetrical and No gut
Aquiferous System
No tissues or organs
Spicules
EX: Glass sponge, demosponge, or calcareous sponge
Ctenophora
Radial and Complete gut
Diploblast development
Nerve net and simple musculature
Zooplankton and cannibal feeders
Cnidaria
Radial symmetry and Incomplete gut
Muscle cells, nerve net, and simple sensory structures
Alt Medusa and Polyp form
Diploblastic with mesoglea between layers
Cnidocytes (Nematocytes use hydrostatic pressure)
Planula Larva
Carnivores (Extracellular and intracellular digestion)
EX: Sea anemone, Coral, Jellyfishes, Hydroids
Arthropoda
Bilateral symmetry and Complete gut
Exoskeleton and Segmentation
Protosome/Ecdysozoa/Bilateria
EX: Insect, crustaceans
Annelida
Bilateral symmetry and Complete gut
Paired Setae and segmentation
Hydrostatic skeleton
Closed circulatory system and cutaneous respiration
Head and terminal part pre and post segmentation
Protosomes/Lophotrochozoa/Bilateria
EX: Earthworm
Mollusca
Bilateral symmetry and Complete gut
Mantle and Visceral body mass and Foot
Radula evolved in this group
Reduced coelom
Open circulatory system with 3 chamber heart
Lophotrochozoa/Protosomes/Bilateria
EX: Snails, Clams, Squid
Chordata
Bilateral symmetry and Complete gut
Post-anal tail, Notochord, Dorsal hollow nerve cord, segmentation
Deuterostome/Bilateria
EX: Dogs, frogs, fish, bird
Echinodermata
Pentaradial symmetry and Complete gut
Calcite exoskeleton, water vascular system, and tube feet
Diffuse nervous system
Deuterstome/Bilateria
EX: Sea star, Brittlestar, Sea urchin
Suspension-Feeding
Aquatic animals collect suspended particles from the water around them
Filter Feeding
Food is separated from water by passage through specialized structures
EX: Sponge, Tunicate, Clam
Deposit Feeding
Terrestrial and aquatic animals that extract food from sediments or detritus by selectively removing digestible particles from soil or water column
EX: Earthworm, sea cucumber
Suction Feeding
Aquatic animals bring food into the mouth along with the water surrounding it
Intracellular Digestion
Small food items taken into individual cells and digested
EX: Sea sponges
Extracellular Digestion
Breaking down larger food items requires an internal cavity
Deuterostome
Blastopore develops into the anus
Mesoderm and coelom form near the outpocket of the gut wall
EX: Echinodermata, Chordata
Protostome
Blastopore develops into the mouth
Mesoderm form near the lip of the blastopore
Coelom forms by a split o the mesoderm
EX: Mollusca, Annelida, Nematoda, Arthropoda
Bilateria Features
Triploblastic
Bilateral
Anterior/posterior axis
Cephalization
Cleavage
Early stage of cell division after zygote formation
Radial Cleavage
Cell divide parallel to 90 degrees to animal-vegetal acis (LMCA)
Spiral Cleavage
Cell divide oblique angle to axis and new cells in furrow
(ONLY Lophotrochozoan)
Triploblastic Development
Formation of complete gut and body cavity (coelom)
3 germ cell layers
Flatworm
Includes free-living flatworm, flukes, and tapeworm
FLUKES: multiple hosts and parasite-induced behavior modifications
Protostome
Nematodes
Medical and agricultural applications
Protostome
Coelom
Fluid filled body cavity formed in triploblastic via mesoderm
Important to hydrostatic skeleton
Anthozoa
Sea anemone and corals
Lg and diverse group of Cnidarians
No medusa stage and solitary/colonial
CORALS: sesslile with calcareous exoskeleton
Sea anemone symbiosis
Hydrozoa
Colonial hydroids form large polymorphic floating coloines where hydra come from
Clade of Cnidarians
Scyphozoa
Sea jellies (“jellyfish”)
Extensive mesoglea
Clade of Cnidarians
Cubozoa
Cube or box jelly
Extremely dangerous and toxic stings
Have eye-like structures
Small clade of Cnidarians
Diploblastic
Two germ cell layers present: ectoderm and endoderm
EX: Ctenophores and Cnidarians
unless cnidarian which have mesoglea
Choanoflagellates
Small group of unicellular/colonial aquatic protists
Collar cells
Single flagellum for locomotion and feeding
Collar cell
Ovoid in shae with collar of microvilli (tentacles)
Features of Metazoa
Multicellular
Diplontic Life Cycle
Distinctive mate gametes
Heterotrophs
Food ingested
Collagen and proteoglycans in extracellular matrix
Gastrulation
Formation of cell layers by invagination of blastula to form gastrula
Aquiferous System
Branched water canal and pore (ostia) system that allowed sponges to filter feed
Sponge Sexual Reproduction
Monoecious but not self-fertilizing
1. Produces male and female gametes different times
2. Sperm released into water to nearby sponges
3. Embryo retained on parent for period of time then released as swimming larvae to settle and develop
Why do sponges experience limited predation?
- not many predators
- biochemical warfare
- produce antimicrobial agents prevent infections
- spicule structures
- biotoxins
Sponge Symbiosis
Mutualism: Cyanobacteria/algae line in sponge and exchange nutrient
Commensalism: Animal inhabit sponge (fat shrimp)
Chitons
Polyplacophora clade in Mollusca
Dorsoventrally flattened
Multiple shell plates and gills
Bivalves
Clade in Mollusca
Paired shells hinged dorsally
Sedentary filter feeders
No radula
EX: Mussel, clam, scallop, oyster
Gastrpod
Clade in Mollusca
Univalve coiled shell with torsion
Mostly herbivores
EX: Snail, limpet, and slugs
Nudibranch
Marine Gastropod (Mollusca)
No shell and very colorful (toxic)
Cerata on back elongated protrusions
Feed sea anemone and hydroids
Ingest nematocysts and expropriate them for defense mechanism
Cephalopod
Clade in Mollusca
Only marine
Predators
Food modifications include tentacle and siphon
Locomotion et propulsion
Cephalopod eye convergent with vertebrates’ eye
EX: Squid, nautiluses, octopuses
Annelid Reproduction
Polychaetes - diocieous with external fertilization and a trocophore larval stage
Others - monoecious with internal fertilization and direct development
ASEXUAL: Regeneration from body fragment
Polychaeta
Clade of Annelida
Well developed head with tentacles and sensory structures
Well developed parapodia and setae
Diverse feeding habits
EX: Sandworm, tube worm, and clam worm
Beard Worms
Gutless worms
Hydrothermal vents
Chemotrophs
Live in chitinous tubes
Clitellata
Clade of Annelida that includes oligochaetes and leeches
Freshwater and terrestrial
No parapodia and tentacles
Clitellum
Oligochaetes
Deposit feeders
Cross-fertilizating hermaphrodites
Egg and sperm in protective cocoon secreted by clitellum
EX: Earthworms
Leeches
Predators and blood sucking ectoparasites
Lack setae
Anterior/posterior suckers
Trilobites
Extinct group of marine arthropods
Abundant and diverse 250-500 mya
Bottom dweller, Scavenger
Chelicerata
Clade of Arthropoda
2 body tagmata: cephalothorax and abdomen
4 pair legs
Predators and Parasites
Appendages: Chelicerae and pedipalps
EX: Horseshoe crab and Sea “Spider”
Myriapoda
Clade of Arthropoda
2 tagmata: Head and trunk
Numerous segments with 1 or 2 pair of leg per segment
Centipede: Carniverous w/ fang
Millipede: Scavengers
EX: Centipede and Millipede
Crustacean
3 body tagmata: Abdomen, head, thorax
Appendages for sensing, locomotion, and respiration
Dorsal carapace
Diverse feeding habits
EX: Crab, lobster, shrimp
Decapoda
Subcategory withing Crustacean including crab, crayfish, lobster, prawn, shrimp, barnacle, krill, sowbug
Hexapods
3 tagmata
1 pair of antennae
3 pairs of legs on thorax
Respiration by trachea
Mandibles (many modifications)
Winglessness ancestral trait
EX: Beetle, butterfly, dragonfly
Hemimetabolous metamorphosis
Incomplete metamorphosis
3 stages: egg -> nymph -> adult
Holometabolous metamorphosis
Complete metamorphosis
4 stages: egg -> larvae -> pupa -> adult
Social Insects
Eusocial insects in colonies with division of labor
Ecologically dominant
EX: Ants, bees, termites
Echinodermata Reproduction
Mostly dioecious with external fertilization
ASEXUAL: Regeneration of body fragment
Sea Lilies, Feather stars
Flower shaped body with oral surface up
Sea lilies attached to a stalk and Feather stars more mobile
Sea Star
Common, largely predatory
EX: Crown of thorns starfish coral predator
Brittle Star
Incomplete Gut
Long slender arms (may be multibranched)
Locomotion by arm movement
Abundant but secretive
Sea Urchin
No arms, but long spines
Ossicles (skeletal plate) fit together into a test
Omnivores, grazers of algae
Sea Cucumber
Soft bodied and slug-like
Greatly elongated oral/aboral axis
Grazers, suspension feeders
Expel part of their gut as anti-predator defense
Groups of Chordates
Lancelets, tunicate, vertebrate
What are the important features of chordates?
Internal skeleton with vertebrae
Jaws
2 pair walking limb
Lancelets
Clade of Chordata
Small filter-feeding marine animals
Chordate features present in adults
Segmented body muscles
MRCA appearance
Tunicates
Clade of Chordata
Sea squirts and relatives
Bag-like with enlarged perforated pharynx for filter feeding
Larvae show chordate characteristics
What is the trends of vertebrate evolution?
Increased cephalization
Increased agility movement
New feeding modes (ex: predation)
“Physiological Upgrading”
Colonization of a wider variety of environments
Jawless fishes
Hagfish and Lamprey
Hagfish
Scavengers on dead animal carcass
No bone, jaw, vertebrae
Tonge with rasping teeth
Tie themselves in knot for leverage
Slime producers
Lamprey
Bloodsucking parasite fish
No bone, no jaw
Sucker like mouth with rasping teeth
Muddwelling filter feeder
Marine and freshwater
Ostracoderms
Extinct
Heavily armored (bony), jawless “fish”
Filter feeder
Silurian and Devonian period (~400 mya)
Placoderm
Extinct
Armor-plated predator with jaw and teethlike structure
1st jaw vertebrate
Silurian and Devonian period (~400 mya)
Chondrichthyans
Cartiliaginous fish
Skeleton flexible cartilage (bone lost)
Pedators, some scavengers
Powerful jaw, good swimmer
EXTINCT MEGALODON
EX: Sharks, rays, skate
Ray Finned Fish
Largest clade bony fish
Diverse feeding habits
Swim Bladder evolved
EX: Cichlid fish, coral reef fish
How does feeding in fish work?
Efficient unidirectional flow into mouth and out through pharyngeal slit
Lobed Finned Fish
Pectoral and pelvic fins modified as robust structures born on a lobe-like stalk
EX: Lungfishes and coelacanth
Colonization of land
Modified of lobed fins to limbs
Use of lungs (modified swim bladder)
Amphibians
Require most environments
Lose water rapidly through skin
Early stages of development require water
What are the 3 clades of amphibians?
Caecilians - limbless
Frogs and Toads - tailless
Salamanders - tailes
Amniote
Reptiles and Mammals
Impermeable skin
Efficient kidneys
Amniote egg - resist desiccation
What are the clades of reptiles?
Lepidosaurs, turtles, crocodiles, and birds
What are the clades of mammals?
Prototherians, eutherians, and marsupials
Prototherians
Echiana, duckbilled platypus
egg-laying
Marsupials
Pouched mammals
EX: kangaroo
Eutherians
“Placental” mammal (well-developed)