annelids Flashcards
classes of annelids
polychaeta
clitellata
class clitellata subclasses
ogliochaeta
hirudinea
what animals are in subclass ogliochaeta?
earthworms
what animals are in subclass hirudinea?
leeches
what characteristics are generally associated w the class annelida?
segments and bristles
BUT found that not all animals in this class have segments OR bristles
former phyla now placed within Annelida
Echiuran
sipunculan
siboglinids
two classifications of polychaeta
errantia
sedentaria
current list of major groups within polychaeta
polychaetes (traditional)
oligochaeta
hirudinea
echiura
sipuncula
siboglinidae
echiura
spoon worms
major group of polychaetes
non-segmented
proboscis curls up to form a sort of “trough”
sipuncula
peanut worms
major group of polychaetes
non-segmented
siboglinids (and major groups + examples)
major group of polychaeta
pogonophora and vestimentiferans
- giant tube worm
- alvinella sp.
- osedax
osedax
whale worms/zombie worms
within siboglinid group
metamerism
aka segmentation
repitition of body structures along anteroposterior axis of the body
*true reptiiton inside and out, not just superficial color patterns
metamerism in clamworms
(nereis spp.)
coelom divided into compartments by septa
- prevents random fluid movement btwn segments
- helps the worm have control over it’s hydrostatic skeleton
- nerve cord is continuous btwn septa
- blood vessels run thru septa
oligochaeta
major polychaete group
“few chaetae”
