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PHYLUM: ROTIFERA “Wheel bearers”- Rotary animals
PHYLUM: ROTIFERA“Wheel bearers”- Rotary animals
Rotifera- “wheel bearers”Small- most 0.1mm-0.5mmAquatic benthic (living at bottom)mostly free-living in fresh water, but
some marine.The anterior part is modified to a ciliary
organ, the corona or wheel organ.Body cavity a pseudocoelom.Cuticle- body coveringBilateral symmetry
Body Plan- Pseudocoelom
Pseudocoelomspace between gut
and mesoderm parts of body wall
space filled with fluid for differentiation of
systems storage of waste
products used as hydrostatic
skeleton
CuticleCuticle- outer covering, over epidermis
◦ for protection against water loss or gain◦ resistant to environmental chemicals
Body Systems Systems they Do NOT have:
circulatory system respiratory system true skeletal system
Do have:
Excretion: protonephridia Digestive: complete- mouth anus Muscular: longitudinal only- whiplike
movements Nervous:ladder like with anterior ganglia Skeletal: hydrostatic skeleton: for
movement Reproduction:most separate sexes,
some parthenogenesis- “virgin birth”- females produce embryos that grow and develop without fertilization by males
Figure 15.18
Phylum Rotifera(rotifers)
have a corona with cilia (like Norelco shaver head)
no cilia elsewhere
Have biforked “foot” with cement glands for attachment
complex digestive structures
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