CHAPTER 19 LOPHOPHORATES

PHORONIDA, BRACHIOPODS, BRYOZOANS

Phylum Phoronida

Marine organisms that live in sediments

Phoronida characters

•Filter feeding •Do not move •Cilia create current to bring particles to tentacles; then to mouth •Metanephridia •Blood vessel contains blood (w/ hemoglobin)

Phoronida

• Hermaphroditic • Sperm released from nephridia, collected by other individual • Embryo = actinotroch

Phylum Brachiopoda

• = “arm foot” • 2-valve shell • Marine lophophorates

Phylum Brachiopoda characters

• At poles or deep marine, permanently attached to substrate • Metanephridia • Circulatory system w/heart and contractile vessels - no blood pigment

Brachiopoda

• Sperm, eggs discharged from nephridiopores • Fert external

Phylum Bryozoa

• Moss animals • Colonial animals that attach to substrate • Marine (5000 species) and freshwater (50) • Fossils (15,000)

Bryozoa

• Secrete a covering around body • Asexual repro, hermaphroditic

Bryozoa

•Sperm into coelomic cavity, released from openings in tentacles •Neighbors collect sperm for fert.

•Some brood embryos

Digestion

• Phoronids, bryozoans: U-shaped • Brachiopods: U-shaped one way tract

Nervous systems

• Ring at base of lophophore, around esophagus, or by pharynx • Mechanoreceptors and chemoreceptors scattered