Blackworms (Lumbriculus variegatus), a second crop from trout farms by Louis Landesman, Ph.D

1
Blackworms (Lumbriculus variegatus), a second
crop from trout farmsbyLouis Landesman,
Ph.D
2
Cherokee Trout Farm, Cherokee, North Carolina
3
Cherokee Trout Farm, Cherokee, North Carolina
4
Rainbow trout, Cherokee Trout Farm
5
BlackwormsLumbriculus variegatus

• Blackworms, Lumbriculus variegatus (Muller),
  are aquatic oligochaete worms living in ponds
  receiving effluent waters from fish farms. They
  are collected and sold as food for aquarium fish.
  Trout farmers in North Carolina and California
  collect blackworms from their effluent ponds.
  This activity provides a supplemental income for
  these fish farmers and helps recycle fish wastes
  which would otherwise pollute local streams.

6
Blackworm biology

• The blackworm, Lumbriculus variegatus Muller,
  usually lives in ponds and lake shores containing
  abundant plant growth and decaying vegetation.
  As for fish food blackworms have several
  advantages. It is fully aquatic and will easily
  survive underwater until eaten by fish. For
  bottom feeding fish the blackworm is a food item
  that stimulates natural feeding behavior. Finally
  since it reproduces by fragmentation a constant
  supply of growing worms is easy to provide.

7
Blackworms in effluent pond
8
Blackworm production

• Blackworms are harvested from the receiving
  ponds by hand. The water entering the receiving
  ponds is turned off allowing a worker to wade
  into the pond and collect surface mud containing
  these worms. The mud is then placed into long,
  shallow wooden troughs with fast flowing water
  running through them. Fine mesh screens are then
  placed over these troughs. The blackworms wiggle
  up through the screens in the presence of light.
  They are then collected and placed in separate
  running water troughs where the worms survive
  until needed by customers.

9
Blackworm troughs, Cherokee Trout Farm
10
Boxes for shipping blackworms
11
Beneficial Use of Effluents

• The culture of blackworms represents a
  beneficial use of organic matter that would
  otherwise pollute surface waters receiving these
  wastes. The trout and sturgeon farms of
  California also raise worms on their effluent
  wastes. This activity sets a good example of how
  to treat aquaculture waste in a beneficial
  manner.