BI236 Lecture Notes - Lecture 10: Nematode, Tardigrade, Body Cavity
Document Summary
Ecdysozoans do not share same body plan. Members of nematoda, nematomorpha, and kinorhyncha are pseudocoelomates. Pseudocoelom is used as a hydrostatic skeleton in nematodes, kinorhynchs, and priapulids while loricifera species vary from being pseudocoelomate and acoelomate. Panarthropoda contains arthropods, onychophorans, and tardigrades which have coelomate bodies but their body cavity is reduced in size. Phylum nematoda: roundworms: about 25,000 species are described. Free-living nematodes feed on bacteria, yeasts, fungal hyphae, and algae while some are saprozoic or coprozoic (live in feces). Predatory nematodes eat rotifers, tardigrades, small annelids, and other nematodes. Important also as food for mites, i(cid:374)se(cid:272)ts" lar(cid:448)ae, and nematode eating fungi. Caenorhabditis elegans is an important model for studies of genomics and cell development and differentiation. Origin and lineage of all 959 cells in the body have been traced from the zygote to the adult (eutely= fixed number of somatic cells). The complete wiring diagram of the central nervous system is known (all neurons and all connections).
