LAB 4 Flashcards
(14 cards)
Annelida key features
triploblastic, eucoelomates, bilateral symmetry, segmented, cephalised and protostomes
what are the two broad divisions within annelids?
errantia (mobile annelids) and sedentaria (sessile annelids)
what are bauplan advances for annelida
well develop coelom, metamerism, cephalisation and furter development to circulatory, excretion and nervous system
annelida reproduction
sexually reproducing with separate sexes. fertilisation can be internal or external and ponce fertilised trochophore larvae devleop
annelids have a well developed hydrostatic skeleton true or false
true
what are annelids nervous system like?
nervous system well devloped with CNS and ventral ganglionated nerve cords
what are sipuncula
peanut worms
what are the defining characteristics of peanut worms
anterior part of the body forms an eversible and fully retractable proboscis with mouth at the end and they also have multiceluar bodies in coelomic fluid
where do sipunculids live
in very small cracks between rocks, burrows and/or abandoned shells
how do sipunculids feed
they have mucous-covered tentacles that trap organic material from surrounding water or sediment
- introvert with tentacles on them
-selective deposit feeding
are sipunculids bilateral or radial
bilateral
what unique structure is found in sipunculids
urns - multicellular structures that are used to collect waste in the coelom which is then transported to a pair of metanephridia
what is sipunculid larval stage
pelagosphera
do sipunculids have a circulatory system?
no
