33 Flashcards
(159 cards)
Invertebrates
are animals that lack a backbone
• They account for 95% of known animal species
Sponges are
basal animals that lack true tissues
they are filter feeders
amoebocytes
cells that use pseudopodia
most sponges are hermaphoridtes meaning:
each individual as both male and female parts
Cnidarians are an ancient phylum of
eumetazoans
eumetazoans
“true animals”
animals with tissues
Cnidarians
- jellies, corals, and hydras
- simple diploblastic, radial body plan
– gastrovascular cavity
– A single opening functions as mouth
and anus
– There are two variations on the body plan: the sessile polyp and motile medusa
nematocysts
cnidae that contain a stinging thread that can penetrate the body wall of prey
Phylum Cnidaria is divided into 4 main classes:
Class Hydrozoa
Class Scyphozoa
Class Cubozoa
Class Anthozoa
Class Hydrozoa
– Polyp and medusa stages
– Most marine and colonial
– Common examples: Portuguese man-of-war and freshwater hydra
Class SCYPHOZOA
- Medusa is prevalent over the polyp stage • All marine
* up to 2 meter in diameter
class ANTHOZOA
• Includes corals, sea fans and anemonies • all marine • medusa stage completely absent • sessile; many colonial
sessile
fixed in one place; immobile.
Class Cubozoa
box jellies, sea wasps
Phylum Ctenophora
• Aka comb jellies
• Used to be grouped with cnidarians but…
– Do not possess cnidocytes
– Use “combs” of cilia for locomotion
lophophore
a crown of cilia that surrounds the mouth
trochophore
larvae that have cilia around their middle
Bilateriates
- Bilaterian animals have bilateral symmetry and triploblastic development
- The clade Bilateria contains Lophotrochozoa, Ecdysozoa, and Deuterostomia
Phylum Platyhelminthes: the flatworms
Triploblasts, bilateral symmetry, dorso-ventrally
flattened
• No blood vessels, no structures for gas exchange, posses a gastrovascular cavity
The Parasitic Platyhelminthes: Cestoda
Parasitic • Most adults infect vertebrates • Possesses a head (scolex) armed with suckers and hooks • Body segments (proglottids) that break off as they ripen with eggs • Lack digestive system • Hermaphrodites but cross mate
Syndermata
Rotifers
are tiny animals that inhabit fresh water, the ocean, and damp soil
– Rotifers are smaller than many protists but are truly multicellular and have specialized organ systems
– Pseudocoelomates
Acanthocephalans
are sexually reproducing parasites of vertebrates
Phylum Mollusca
Molluscs are soft-bodied animals, but most are protected by a hard shell
– Muscular foot – Visceral mass – Mantle
• Many molluscs also have a water-filled mantle cavity, and feed using a rasplike radula
Mollusca:
the 8-plated chitons
Class Polyplacophora
consists of the chitons, oval-shaped marine animals encased in an armor of eight dorsal plates; foot used for locomotion; has radula.