Annelids and Allies

Phylum Sipuncula — Peanut Worms

• benthic

• sedentary

• no segmentation / setae

• no CS or RS

• asexual reprod.

• sexes separate

Phylum Annelida

• triploblastic

• coelomate

• protostomes

• lophotrochozoa

• worms and leeches

Clade Chaetopteridae — Parchment Worms

• benthic

• form u-shaped tunnels

• specialized parapodia for feeding

• bioluminescence

Clade Errantia — Polychaetes

• typically predators

• SS = dorsal and ventral nerve cords, ganglia, eyes, nuchal organs, statocysts

• no permanent sex organs

• gas exchange with parapodia, gills, and diffusion

• varying CS

• varying O2 carrying pigment

• sexes separate

• temporary gonads

EX: clam worms, scale worms, fire worms, palolo worm

Clade Siboglinidae — Beardworms

• benthic

• construct, and live in, tubes

• no mouth or DS

• mutualism with chemoauto. bacteria

• separate sexes

Clade Echiuridae — Spoon Worms

• sausage-shaped

• unsegmented

• flattened, evertable proboscis

• simple NS

Clade Oligochaeta — Intestines of the Soil/Earthworms

• loss of parapodia

• reduction of setae

• distinct reprod system

• clitellum

• hermaphroditic

• direct development

• nocturnal

• process body weight in soil/day

• scavengers

• calciferous tissue, crop, gizzard, typhlosole

• CS = double transport system, dorsal vessel is heart, ventral vessel is aorta

• gas exchange through diffusion

• 1 pair nephiridia per segment

• NS = cerebal ganglia, ventral nerve cord, neurosecretory cells, giant axons

Class Hirudinida

• dorso-ventrally flattened

• no septa

• crawl

• true leeches

• specialized organs for storage of blood

• most feed on fluids

• secrete anticoagulants and anesthetics

• chitinous jaws

• coelomic cavity filled with tissue and lacunae

• medical benefits — anticoagulant and antiinflammatory