Blackworm Facts
Kingdom
Animal: eat food, many cells, move
Phylum
Scientific Name
Environment
Regeneration
Annelida (Segmented worms)- divided into many parts (segments)
- earthworm
- leech
Lumbriculus variegates
Shallow edges of pond, marshes, and lakes in North America and
Europe
Takes 2-3 weeks to regenerate
Cut the worm in 1/2 , you get 2 new worms
Regenerate both head and the tail
Regenerated parts are lighter in color
Feed on various microorganisms and decaying vegetation like decomposing leaves, rotting logs, or
sediment
Food
Reproduction
Hermaphrodites: contain male and female sex organs
In nature, it is believed, but never documented that they exchange sperm with other blackworms and
produce cocoons which contain 4-11 fertilized egs each
The embryos develop in cocoons for 2 weeks and then emerge as small worms about 1 cm long
In the lab setting, reproduction is usually by asexual fragmentation where the worm divides into 2 or
more fragments and then each fragment rapidly forms a new worm
Gas Exchange
Tail end
Stretches tail to surface of water and breaks through the water forming a right angle. The tail takes in
oxygen and releases carbon dioxide.
Movement
Two layers of muscle act in opposition to each other
Segments alternately constrict and lengthen.
Smaller muscles control the chaetae (bristles) that provide traction for the worm
Circulation (blood)
Blood is in blood vessels like humans: Closed circulatory system
Blood carrying oxygen and food can travel faster in a closed system
than in an open system
Blood is pumped from the posterior end through the dorsal blood
vessel and back through the ventral blood vessel.
The tail can detect an approaching shadow or sudden vibration using its photoreceptors
Blackworm then quickly contracts its muscles and shortens its tail
They also react when approached at the anterior end as well
Protection
Invertebrate
10 cm
150-250 segments
Other