Spawning Mops
Text by Paul Barrow
Click on thumbnails for larger picture

Reasons for Using Mops
Mops are a convenient t way of spawning many fish, which lay their eggs in plants. It can be difficult to get hold of the right type of plant, couples either the need to keep the correct condition for plant and breeding fish, it is more convenient to use mops. Mops can be sterilised by boiling; this means no pathogens or parasites can be transferred into the tank, and the danger of hybridisation between similar species is eliminated.
Materials
Don’t use natural materials such as wool - you only make that mistake once. Wool will quickly break up into short fibres, which will cover the base of the tank and posed a choking threat to fish, especially fry. Better to use man-made fibres such as nylon.
Colour
Many years ago, the British Killifish Association tested mops of many colours to see which was best. Their conclusion was it made little difference as long as the mop was dark; white or light colours still worked but not as well as the dark ones. The commercially made, white mops can be dyed with products such as DYLON – dark green being the most aesthetic
Maintenance of mop
Mops should be boiled, or at least scalded, between uses to stop the transferral of diseases. This process also kills of eggs from previous spawning – you don’t want female killies of different species mixing.
Step-by Step Guide

(1) Tape 2-4 strands of wool, or 1 strand of string, along the spine of a suitable hardback book (120-150mm wide). This will later be used to tie the mop together, and taping it prevents a tangle when winding the mop.

(2) Next tape the end of a hank of wool to the book and wind on about 100 loops (this can be modified to suit the fish being spawned, but 100 loops makes a good, average sized mop.

(3) When the strands have been wound on, release the ends of wool taped to the spine.

(4) Tie a knot in this piece of wool ensuring it is tight as possible and the loop of the wool won’t pull free.

(5) Cut the loop at the opposite end to the knot, scissors may work but a craft knife is usually needed.

(6) The basic mop is completed and should look like the picture. Do not cut the wool where it is knotted as this is used later.

(7) Tie the free ends of the knotted wool to a rock for a sinking mop, which will fan-out on the base of the aquarium for used by bottom spawners.

(8) Top spanners can be catered for by hanging the mop over the edge of the tanks or by floating it with a piece of polystyrene or cork. Cut a slot halfway through your chosen material as shown in the photo.

(9) Slide the free ends of wool into the slot and pull the mop tight against the polystyrene. There is usually no need to tie this as the friction of the float hold everything in place.

(10) The mop should hang like this in the water.