| THEY
HAVE/ARE |
THEY DON'T HAVE |
| An outer cuticle and ventral
cilia |
A body cavity |
| Bilaterally symmetrical and worm-like |
Circulatory or gaseous exchange systems |
| A body covered in spines,
hooks and adhesive tubes |
|
| A through gut and
anus |
|
| A nervous system and two
longitudinal cords |
|
| Hermaphrodite or
parthenogenic |
|
| Aquatic |
|
 |
Gastrothrichs (hairy-backs) are
small (less than 4 mm), dorsoventrally flattened, transparent worms. At the
anterior end they have sensory bristles, cilia, sensory pits, and some species
have eye spots. The body ends in a tail or fork. Over 400 species are known.
They inhabit interstitial spaces in sand and compadted surfaces, and move using epidermal cilia, or
loop in a leech-like fashion using adhesive tubes, see Chaetonotus sp. on the right which has two adhesive tubes. Males tend to be rare and
poorly developed. On the left is Chaetonotus maximus, a freshwater gastrotrich. |
 |
|
|
Stonehaven, Scotland
|
![[]](http://m3.moostik.net/img/?pseudo=bumblebeepages&cpt=IGastrothricha&option=invisible)