Week 4 Flashcards
Spiralia
2 groups of Platyhelminthes
Free-living (formerly Turbellaria)
Parasitic (Neodermata)
Apomorphies for Rouphozoa (also applies to Spiralia)
- Multiciliated epidermis and gastrodermis
- 2 cilia per prontephridial terminal cell
Tripoblastic
True endomesoderm
Mesenchyme
Space between body wall and internal organs
Nephridioducts
Excretory ducts; drainage or storage (osmoregulation)
Flame duct
Drains into nephridioducts
Rhabdites
Rod-shaped secretions (slime secreted by epidermal glands) in Platyhelminthes
Viscid gland vs releasing gland
Adhesive function (Platyhelminthes) vs de-adhesive function/deattachment
Platyhelminthes musculature (what muscles)
Circular
Longitudinal
Dorsoventral
Platyhelminthes nervous system
Nerve cords + nerve net
Acoel => contains statocyst
Polyclad => contains nerve cord
Triclads => contains nerve cord + commissure
Platyhelminthes digestive system
Mouth (no anus because protostomes)
- Phagocytic, gland cells
- Gastro-vascular
Syncytium (function Platyhelminthes)
ion, water and molecular transport between the syncytium and the external environment + protection from external environment
Neodermata apomorphies
Neodermis (named after apomorphy) = adaptation to parasitic lifestyle (protection from host gut enzymes, etc.)(non-ciliated)
Monogenea and Trematoda apomorphies
Large, complex ventral adult sucker
Rotifera apomorphies
- Ciliary corona on head
- Unpaired retrocerebral gland
- Female has vitellarium
- Pathenogenesis
Lophophorata characteristics
- Lophophore
- Sessile or sedentary suspension feeders
- No distinct head
Lophophore (structure + function)
Crown of hollow, ciliated tentacles encircling mouth
- Upstream collection system for suspension feeding
- Gas exchange
- Hollow space in tentacle is part of coelomic space
Autozooid (function)
Feeding zoids
Heterozoid (function)
Non-feeding zooids
Avicularia (function)
Jaw-like mechanism
Vibracula
Large cilia-like structure use to keep colony clean; sometimes for locomotion
