Slide 1 Our next group of protostome animals are the annelids.
Slide 2 Phylum Annelida consists of earthworms, leeches, and marine polychaete worms. These protostome coelomates are the first group to exhibit body segmentation. These organisms live in both terrestrial and aquatic environments and they are both free living and parasitic.
Slide 3 Segmentation is not well-developed in the annelids but is does provide benefits to these organisms. Segmentation of the body allows for specialization of discrete parts of the body. It also allows for more advanced mobility because a segmented organism can move parts of its body independently.
Slide 4 Some of the annelids can get quite large - like this giant earthworms found in places like ecuador and australia.
Slide 5 The marine polychaete worms are an aquatic group of often beautiful feathery worms.
Slide 6 Earthworms play an important role in developing high quality soils. When they burrow through soils they help to aerate soil and when they digest food and excrete waste this adds nutrients to the soil. In a square meter of soil there may be as many as 32,000 worms that may ingest and excrete 3 metric tons of soil per year.