Phylum Nemertea (Rhynchocoela)

More documents

Recommendations

Info

Excretion and Osmoregulation 2 to 1000s of protonephridia, similar to those of flatworms. Number depends on the habitat. Some terrestrials may have up to 70,000 clusters of flame bulbs Protonephridia associated with lateral blood vessels, sometimes immersed in blood (B) They aid in osmoregulation in freshwater and terrestrial nemerteans Terrestrial species (e.g. Geonemertes) inhabit moist environments to avoid desiccation. Also some are covered in mucous. Minimal osmoregulation problems in open water or benthic nemerteans In some species, nephridioducts are syncitial and open up to 1000s of epidermal pores
Nervous system <strong>Nemertea</strong>ns more cephalized than flatworms. Nervous system a simple net, dominated by a brain derived from 4-5 ganglia. 5 longitudinal nerve processes stem from the brain and innervate the mouth, proboscis, gut and ocelli. Eyes anteriorly (2-100s in FigureB) Chemotactic; cephalic slits, cerebral organs, frontal glands (FigD) respond. Cephalic slits are lined up with ciliated sensory epithilium. Water moved through the slits. Frontal glands open to a pitlike-frontal sense organ (FigD). Some spp. have statocysts Cerebratulus
Page 1 and 2: Phylum Nemertea (Rhynchocoela) Gree
Page 3: Nemertean Bauplan “Functionally
Page 6 and 7: Feeding and digestion Proboscis is
Page 8 and 9: Comparison of Proboscis Types Credi
Page 10 and 11: Circulation and Gas Exchange Nemert
Page 14 and 15: Cerebral organs of nemerteans Most
Page 16 and 17: Epidermis Frontal gland Esophagus R
Page 18 and 19: Development Paleonemertea, Hoplonem
Page 20 and 21: Late-stage Cerebratulus sp. Pilidiu
Page 22 and 23: Nemertean Taxonomy Nemerteans are c
Page 24 and 25: Are Nemerteans sister taxa with fla

Phylum Nemertea (Rhynchocoela)

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?