White Worms
By: Roger Winter

Whiteworms are the bigger brothers of the Grindal worms.  Again they provide a valuable source of protein and fats for the fish. Whiteworms are very suitable for both marine and freshwater fish being free of water borne pests and diseases. Larger than Grindal worms they are up to 1 inch / 2.5cm long and are readily taken by all adult fish and some of the larger fry. They are segmented round worms that are closely related to the earthworm. When viewed under magnification this relation is very apparent even down to the small bristles on the outside of the body that propel it through the medium. They are an opaque white in colour, hence the name and occur naturally in soil. Well worked compost heaps will normally be holding a large population of these worms. They cannot stand dry soil, other places were they abound is in damp leaf litter and the banks of ponds and streams. The worms prefer to remain near the surface but dry conditions will drive them down deeper in the soil. They perform the same functions as earthworms and study has suggested that the actually turn over more soil than the earthworm and control the pH of the soil and prevent it becoming to acidic. Reproduction is exactly the same as that described for the Grindal worm. Their temperature requirement are lower than that for Grindal worms, 60^o F / 16^o C is optimum as below 35^o F / 2^o C they stop breeding and above 75^o F / 24^oC the worms will die.

As the worms are larger and fish will gorge on them and they are best restricted to a supplementary feed as some aquarists swear that it caused obesity especially in breeding females. They will survive under water for several days and even live for hours in sea water. They do unfortunately sink to the bottom and being adverse to light will bury into the gravel out of reach of most livebearers but catfish, loaches and snails will root them out and even some of the livebearers will grab any that poke their head out of the gravel. As dead worms can soon foul a tank it is best to use a worm feeder or similar device to restrict the number of worms escaping into the tank at once, the fish soon learn were this treat is coming from the only problem being that some of the larger fish may bully the weaker ones away, A simple solution to this is to use two feeders. Do remember to remove the feeders when they are empty as some fish in their eagerness to reach the worms may jump in and be trapped in the feeder. White worm cultures can be obtained from the specialist suppliers who also sell special food and culture mediums or from a fellow aquarist who has a culture as they are easily propagated.

The old method of culturing the worms was to use shallow wooden trays about 12 in by 10 in and 3 in deep. The tray was filled to three quarters of its depth with good quality garden loam over which was placed a piece of glass and then covered with sacking. Time has moved on and more modern containers are available. Particularly suitable are the shallow variety of ice cream tubs and for a small culture the plastic bait box as sold in every fishing tackle shop is perfect. The most suitable container available are the Polystyrene foam fish boxes especially the half height ones as they meet all the requirements for Whiteworm culture of retaining moisture and a steady temperature.

The container should be three quarters filled with a suitable soil medium. The type of medium is again an area were experimentation with different mediums may pay off. Do not use peat unless it has had most of the acids leached or boiled out as the worms prefer a neutral or slightly alkaline soil to breed in. I have found that the ready mixed all purposes, peat based, composts from any garden centre work best for me and do not require sterilisation before use. All containers and garden soils should be thoroughly sterilised before use to inhibit the growth of bacteria. Technology to the rescue as nothing is quicker than nuking it in the microwave. The medium should be damp but not soaking, about as damp as very fresh rolling tabacco. If it will hold into a ball that breaks into pieces when pressure is applied then it is about right. A piece of glass should then be placed over the soil with a gap round the edges for the soil to breath and a cover placed over the lot to keep out the light and pests.

When first starting a culture I mix a quantity of instant oats into the soil to encourage the worms to spread throughout the medium. I place half a cooked potato with the skin on (prevents the potato going mouldy with exposure to the air) pressed lightly into the soil surface and replace the covers. The culture is then checked daily until the potato has all been eaten or started to foul, in which case it is replaced. When it appears the worms have started breeding lightly stir the soil to check that a large number of worms are distributed throughout the soil. Feeding and harvesting can now begin, sprinkle a small quantity of instant oats over the surface of the medium. Check daily, if all the oats have gone and no worms are visible on the surface then add a slightly larger quantity of oats. If all the food has not been eaten then remove any that has started to foul and replace the cover. Once the correct quantity of food is reached then when you lift the cover a large quantity of worm should be found feeding on the surface and may be picked out in clumps with tweezers or scraped of the glass. The worms are very light sensitive and within a few moments all those that can bury back into the soil will have done so.

Other foods that are used include vegetable scraps, stale white bread soaked in a little milk, dog and cat dry foods and malted milk powders, whatever is used do not overfeed and remove any soiled or contaminated food daily. Worms will survive for long periods without adding food but if the culture becomes to dry then they will die. If a culture becomes to wet the worms will migrate out of the soil and swarm up the sides of the container. If this situation is not quickly remedied the worms die and all you are left with is a foul smelling mess guaranteed not to make you popular.

Two methods of separating the worms from the medium when required are as follows One place the whole culture over a low wattage source of heat and the worms will migrate upwards away from the heat and gather on the mediums surface and sides of the container. Two Take a quantity of the medium and place it in a shallow container then add water until the surface of the medium is covered with a half inch or so of water and cover. Within ten minutes the worms will have migrated out of the medium and gathered in balls on the mediums surface from were they can be removed with tweezers. After removal of the worms drain the medium through a fine mesh net an squeeze as much water out a possible the return it to the culture and add food.

The length the culture remains healthy and productive is dependant on the size of the container and the quality of maintenance. I have maintained a culture in a bait box for over a year but this is unusual in such a small container and normally would be viable for about three months whilst a healthy culture in a large poly box should last a couple of years. New culture are simply started by adding a quantity of worm to a container set up as above. Normally two to three weeks is required before production is in full swing but again if conditions are to the worms liking worms may be harvested within the week. As with all live food cultures it is always best to set up two or three not only so that you can rotate them and give the culture time to rest and breed but in the unfortunate event of losing a culture you have a starter for a new culture.

The main drawback to culturing Whiteworm are the pests they attract. The food can attract rodents and healthy cultures are sometimes infested with fruit flies, when you remove the cover little black flies form a dense cloud above the container blocking out your view of the divorce papers. These are not normally to bad and moving the culture to a cooler location and keeping the lid on until you can remove it in the open air will normally dispense with these pests within a week. Tight fitting lids or covers with only the smallest holes for ventilation should be used as the culture will attract various flies and insects if easy ingress is possible. Another common pest are mites these appear as tiny dots moving on the surface of the medium and are normally associated with to damp conditions so allowing the culture to dry out a little will often cure this. Sometimes larger mites that move fast and disappear into the soil when exposed to light appear in large numbers. These are probably springtails that occur naturally in soil, if present in large quantities then soak the culture in deep water and agitate, the mites will float to the surface and can be removed by netting or pouring off.(Many surface feeding fish will eat these). Simply pour the remaining medium through a fine mesh net or ladies stocking and squeeze dry before returning to the container.

The last problem is mould. If you have a very heavy layer of mould or fungi on the surface it is due to either overfeeding or non sterilisation of the medium. Remove as much as possible and stir the remainder into the medium, add a thin layer of sterilised medium over the surface and do not feed the culture for seven to ten days. This will often cure the problem but if it persists then dump that culture and start a new one.

With Permission from
Viviparous