Chapter 17: Annelids

Flashcards created to review key concepts and information about annelids from the lecture notes.

Phylum Annelida includes segmented worms such as __, __, and __.

earthworm, leeches, beardworms

The hydrostatic skeleton in annelids is formed by a coelom filled with __.

fluid

Annelids are classified as __ because they possess a coelom and develop a trochophore larval stage.

coelomates

The two main groups of annelids in the new taxonomy are and .

Errantia, Sedentaria

Errantia typically includes mostly __ that are free-moving and often predators or scavengers.

marine polychaetes

Leeches belong to the group of annelids characterized by and a .

clitellum, parasitic or predatory behavior

In Errantia, the main respiratory organ is the __ which is located on most segments of the trunk.

parapodia

The reproductive structures in Earthworms known as __ are responsible for secreting cocoons.

clitellum

Sedentaria includes worms that live in or , using parapodia to move and capture food.

tubes, burrows

Siboglinids (beardworms) absorb nutrients through their __ and rely on symbiotic bacteria for energy.

tentacles

Earthworms are known as the __ of the soil due to their significant role in soil aeration and mixing.

intestines

True leeches have __ suckers and are often either predatory or parasitic organisms.

two

Annelids exhibit __, which refers to their segmented body structure composed of repeated units called metameres.

metamerism

The __ of annelids are often equipped with setae that assist in movement and anchoring.

segments

Annelids use a hydrostatic skeleton for movement, relying on the contraction of and muscles.

circular, longitudinal