Lophotrochozoa Flashcards
What is Lophotrochozoa?
Clade bilateria and the majority of animals as they exhibit bilateral symmetry.
Triploblastic, with muscle tissues and organs that originate from mesoderm, both a mouth and anus, and differentiate along the anterior posterior axis
Phylum Acoela
Lophotrochoza clade that are basal to other bilaterians.
Small flattened body with minimal cephalization and simple nerve net (no brain)
NNo body cavity or complex organ systems.
Simple digestive systems w/ mouth, but no gut cavity or anus
Clade Lophotrochoza
Exhibits the widest range of animal body plans with no single unifying characteristics.
Clade Lophotrochoza Examples
Flatworms
Rotifers
Ectoprocts
Braciopods
Molluscs
Annelids
Phylum Platyhelminthes
Flatworms.
Simple body pland with triploblastic development that LACK fluid filled body cavities.
Incomplete digestive tract w/out an anus and no circulatory system or gas exchange
Platyhelminthes Two Lineages
Catenulida
Rhabditophora (Planarians, Trematods, and Tapeworms)
Two Groups of Phylum Syndermata
Rotifers and Acanthocephalans
Rotifers
Group in Phylum Syndermata
Microscopic, multicellular with organ systems
Reproduce by parthenogenesis
Acanthocephalans
Phylum Syndermata
Sexually reproducing parasites that inhabit vertebrate hosts, lack a complete digestive tract, and absorb nutrients directly from their hosts
Lophophorates
Feed through a lophophore (a fan of ciliated tentacles surrounding the mouth)
Either Ectoprocts or Brachiopods (both sessile, but have motile larval stages)
Ectoprocts
Sessile colonial Lophophorates that superficially resemble coral
Encased with a hard exoskeleton and are suspension feeders using a retractable lophophore
Brachipods
Lophophorates that superficially resemble bivalve molluscs like clams
Suspension feeders using paired lophophores with a complete gut and anal opening
Lophosphore
A fan of ciliated tentacles surrounding the mouth that characterize Lophophorates (Ectoprocts and Brachiopods)
Trochozoans
Molluscs and Annelids that share patterns of early embryonic development including microscopic motile trochophore larvae
Phylum Mollusca
Trochozoans such as snails, slugs, oysters, clams, octopuses and squids
Soft-bodied animals protected a by a hard calcareous shell, an open circulatory system, separate sexes, and a life cycle including a ciliated trochophore larval stage
Phylum Mollusca Three Primary Parts
- Muscular ventral foot used for locomtion
- A visceral mass above the foot containing internal organs
- The mantle is a thin tissue layer that secretes the shell
Four Major Classes of Mollusca
- Polyplacophora (chitons)
- Gastropoda (snails and slugs)
- Bivalia (clams, oysters, and other bivalves)
- Cephalopoda (squids, octopuses, cuttlefish, and chambered nautiluses)
Chitons
The major class of Mollusca: Polyplacophora
Oval-shaped marine animals w/ a protective shell of 8 dorsal plates. They use their food as a suction cup to adhere to rocks
