Lecture 7

Question 1

difference between metamerism and tagmatization

Question 2

anatomy of Errantia clades

Answer 2

mostly marrine

parapodia with prominent lobes/setae

mobile predators with ‘jaws’

some can be bioluminescent

most semelparous

Question 3

anatomy of sedentaria clades

Answer 3

marine, freshwater and terrestrial habitats

• parapodia reduced or lacking setae associated with body will directly

tubeworms,
- parchment like, calcareous or cemented sand grains, some are burrowers, filter feeders

beardworms,
- deep water marine habitat, no muth or gut, symbiotic relationship with chemoautotrophic bacteria

spoon worms

and clitellata
- earthworms and leeches, lack parapodia, satae anchored in body wall, clitellum, monoecious without larval stage

Question 4

reproductive characteristics of Errantia clades

Answer 4

• mostly dioecious
• fertilization internal or external
• gametes released from coelom via nephridia or through body wall (body disintigrates), often semelparous (one reproduction event)
• trochophore larvae

Question 5

reproductiv characteristics of sedentaria clades

Answer 5

clitellata
- monoecious; copulation involves mutual sperm transfer

• eggs usually laid in protective cocoon; direct development
• can sometimes be asexual (split in half)

Question 6

structure and function of the metanephridia

Question 7

describe the variation in digestive systems among different groups of annelids

Question 8

phylum annelida

Answer 8

lophotrochozoa

segmented worms

most marine

body metameric
paired epidermal setae

closed circulatory system

ventral nerve cord with dorsal suprapharyngeal ganglia

protonephridia or metanephridia

two clades of uncertain taxanomic rank; sedentaria and errantia

polychaetes = annelids (nontaxonomic term)

parapodia prostomium

Question 9

parapodia

Answer 9

paired unjointed segmented lateral extensions from the body wall

Question 10

prostomium

Answer 10

fleshy segment/extrusion that is part of the head