Invertebrates Flashcards
Parazoa
Porifera (sponges)
Porifera (sponges)
sequential hermaphroditism gametes from choanocytes or ameobocytes eggs stay in mesohyl sperm released from sponge and enter other sponge via pores larvae are free swimming
Ctenophora
Movement by cilia A few mm to 1.5 m Found in marine systems comb jellies Radial
Cnidarian
Radial
Diploblastic
Polyp and medusa phase
Venomous
Clades of Cnidaria
Hydrozoa, Scyphozoans, Cubozoans, Anthozoans
Hydrozoans
Polyp stage more conspicuous
Fresh water and marine habitats
Can reproduce by budding
Portuguese Man o’ war
Scyphozoans
Medusa is obvious stage
Pelagic species lack a polyp stage
most are jellies
Cubozoans
box shaped medusa
complex eyes
highly toxic cnidocytes
Anthozoans
medusa stage absent
most are sessile
Sea anemones and coral
Eumetazoa contains
radial dibloblasts -Cnidaria -Ctenophora Bilateral (triploblasts) -Protostomes *Platyzoa *Lophotrochozoa *Ecdysozoa -Deuterostomes *Echinodermata *Chordata
Clade Platyzoa
small bilateral animals no respiration system no circulation system some acoelomates some pseudocoelomates free living and parasitic
Phylum Platyheminthes
Flatworms
Marine, freshwater, and damp terrestrial
Triploblastic acoelomates
water and gas exchange by diffusion
Phylum Platyheminthes contains the clades:
Turbellarians, Monogeneans and trematodes
Turbellarians
Free living and found in marine habitats
Planarians
reproduce asexually by fission
Hermaphrodites
Monogeneans
parasites both in and on hosts
Parasitic on fish
Trematodes
parasitic
sexual and asexual stages
some reproduce asexually through fission
hermaphrodites - mates fertilize eachother
Phylum Rotifera
fresh water, marine and damp terrestrial habitats
Alimentary canal separates mouth and anus
reproduce by parthenogenesis (asexual reproduction)
Bdelloidea
In phylum rotifera
Asexual
no males, 40 MYA
incorporates DNA from environment
Clade Lophotrochozoa
Highly diverse body forms
multiple phyla
some develop lophophore for feeding, some trochophore larval stage, some neither
Platyzoa contains
Rotifera and Platyhelminthes
Lophotrochozoa contains
Brachiopoda, Bryozoa, Annelida, Mollusca
Brachiopoda
“lamp shells”
Resemble clams
Shells are dorsal/ventral not lateral like mollusks
Marine
Byrozoa
colonial animals
encased in exoskeletons
Reef builders
Marine and freshwater
Annelida
segmented worms
marine, freshwater, and damp terrestrial
coelomates
Annelida contains
oligochaete, Polychaeta, Hirundinea
Oligochaeta
Earthworms and aquatic species
Improve soils for farmers
Hermaphroditic
some asexually reproduce
Polychaeta
free living
mostly marine
Parapodia - ridge-like structures used in locomotion
bristle worms
Hirundea
leeches
parasites, predators, and detritivores
freshwater
medicinal
Mollusca
mostly marine but also fresh water and terrestrial
secrete hard shell made of calcium carbonate.
3 body parts of mollusks
- muscular foot
- Mantle - fold of tissue over visceral mass
- Radula - rasping feeding organ
Mollusca contains
Polyplacophora, Gastropoda, Bivalvia, Cephalopoda
Polyplacophora
Chitons
shell divided into 8 plates
intertidal marine habitat
consume algae with radula
Gastropoda
Largest class of muscles Marine, freshwater, terrestrial snails and slugs Torsion rotates visceral mass - anus near head Hermaphroditic
Bivalvia
Shell divided in 2 No distinct head No radula some have eye spots gills for gas exchange filter or suspension fillers clams
Cephalopoda
Predators octopus and squid well developed sense organs complex brains beak-like jaw closed circulatory system most do not have shell Chromatophores Photophores
Chromatophores
organs that allow organisms to change color by distorting cytoplasmic sacculus
Photophores
organs that allow bioluminescent light to shine from organism
Ecdysozoa
Covered by tough coat called cuticle
cuticle shed or molted through process called ecdysis
2 largest phyla are nematodes and arthropods
Ecdysozoa contain
Nematoda and Arthropoda
nematoda
Round worms water, soil, plant, and animal tissues no circulatory system alimentary canal most are separate sexes with females able to produce 100,000 fertilized eggs per day Parasitic - hookworm, heart worm, pinworm crop pests key soil species
Arthropoda
10^18 arthropods Alice on earth
most successful phylum
535-525 MYA
Arthropoda contain
Chelicerata, Myriapoda, Hexapoda, Crustacea
Chelicerata
Chelicerae - pincers or fangs
Body composed of cephalothorax and abdomen
No antennae
Earliest were water scorpions
Most species extinct except for sea spiders and horseshoe crabs
Chelicerata contain
Arachnids
Arachnids
Largest group. Cephalothorax has 6 pairs of appendages -chelicerae -pedipalps used for sensing, feeding, reproducing - 4 pairs legs
Myriapoda
Millipedes and centipedes
all are terrestrial
all have pair of antennae and 3 pairs modified appendages serving as mouth parts
segmented.
Millipedes
2 pairs of legs per segment
detritivores
Centipedes
1 pair legs per segment
carnivores
have venomous claws
Hexapoda
More species in Hexapoda than all other forms of life combined insects and springtails six legs terrestrial and fresh water flying species numerous
Hexapoda include
insects
simple (incomplete) metamorphosis
nymphs resemble small adults
series of molts make nymph look more like adult
final molt produces sexual maturity and wings
Complete metamorphosis
specialized larval stage (grub, caterpillar, maggot)
larval stage looks different than adult
Insects contain
Coleoptera, Lepidoptera, Diptera, Hymenoptera, Orthoptera
Coleoptera
Beetles
complete metamorphosis
most diverse species
Lepidoptera
Butterflies and moths
complete metamorphosis
Diptera
flies
complete metamorphosis
Hymenoptera
Bees, wasps, ants
Complete metamorphosis
Orthoptera
Grasshoppers, crickets
simple metamorphosis
Crustacea
variable number appendages
gas exchange across cuticle or by gills
crustacea contain
isopods, decapods, copepods
isopods
wood lice and other species
terrestrial, marine, fresh water
decapods
lobsters, crabs, shrimp
carapace is hardened cuticle on dorsal cephalothorax
copepods
krill and other species
planktonic crustaceans
