Mating
The actual act of mating is quite remarkable. Each worm’s male and female organs comprise one pair of ovaries and two sets of testes. In mating, when two worms are involved, they move towards each other and overlap, until their clitellums are adjacent. Then a thick layer of mucus is exuded, wrapping them tightly together, and sperm is ejected under this blanket. Each partner then takes the other’s sperm into the body, for storage in a special sperm storage duct.
The worms then separate and the clitellum excretes a thick albuminous ring quite quickly. The worms immediately begin to wriggle out of this ring backwards. As the ring is worked forward it passes over the ovary ducts, where it collects the ovum. Further wriggling moves the ring over the sperm storage ducts, where the sperm is collected and fertilisation takes place. Blues don’t need a partner, they simply form a ring around the clitellum and wriggle backwards, passing the ring successively over the ovum and sperm ducts, so that ova are deposited and self-fertilisation occurs.
In the wondrous world of worms, there are even a few species which have a penis (or two or even four) of sorts and at fertilisation insert them into their mates (simultaneously). From then on, a capsule is formed in the usual way.
All the sperm taken into storage is not used at once It is held in the sperrnathecae (storage sacs) where it is nourished and used, a little at a time, to fertilise capsules as they are formed. Many capsules are produced from one mating.
Eventually, with all worms, as the wriggling continues the ring passes over the snout and as it does so the ends close as if drawn together by a drawstring, and the capsule containing the eggs is deposited in the worm bed or the soil. Capsules, which are usually a little smaller than a match head, are closed at one end, but with an obvious escape hatch.
I have a theory that the size of the worm (which determines the size of the ring) and how energetically it wriggles (which decides how quickly the ring passes over the sperm storage and ovum ducts) may dictate the number of ovum deposited and the number of these actually fertilised. However, the wise owls of the worm world may not agree with this.
Fertility
At maturity Blues arc by far the largest of the three species, reaching a length twice that of Reds and Tigers.
Under my own trials, which provided them with ideal conditions of 25°C and 40 per cent moisture, they reached sexual maturity in thirty-six days. At this time they measured 75 mm long, 4 mm thick and weighed 0.7 grams. They took another sixty days to reach 1.2 grams at which time the beginnings of phospherencence was noticeable. In about six months they grew to over 200 mm long and in this fully mature state phosphoresced like a flashing neon tube enclosed in a red sheath.
Because during the colder months Blues reproduce very little at all, from observation and deduction I believe they can be expected to double their population every month, averaged over twelve months. Most certainly, they will breed more quickly than Reds and Tigers. However, this to a degree is speculation because much more is known about the Reds and Tigers which have both been exhaustively investigated and have been the subject of numerous laboratory trials.
Reds have been recorded as reproducing 106 times in one year. (This observation did not require the researcher to sit and watch what was going on for twelve months, but merely to remove and count the capsules produced by the two worms being monitored.) On average, four young are produced per capsule. One is common and twenty-two have been reported. I have personally seen two, nine, fifteen and many single hatchings. In the wild, the mating frequency is thought to be as low as ten times per year with only one or two young per capsule.
Tigers will average fifty capsules per year. Like the Reds, they average four young per capsule and the young of both achieve sexual maturity in sixty to ninety days, depending on bed conditions.
Hatching
Freshly formed capsules arc milky but as time passes they actually darken until, immediately prior to the young emerging, ey are a deep rusty colour. If the worm bed temperature is 18° 25°C and nicely moist, not wet, they could hatch in as little as fourteen days, but the process can take up to five weeks. Under variable conditions capsules have been known to retain their fertility after six years.
At birth, the young look like threads of white cotton only a few millimetres long. At first, they seem to go towards the bottom of the bed, but within a day or so they change to their characteristic our and climb towards the top. They are quite self-sufficient m birth.
The Worm Bed
Worms breed best if the bed is kept sufficiently damp to allow them to replace the moisture they lose. Daily living for a worm involves losing about 20 per cent of its body weight in moisture. The bedding must therefore be sufficiently moist for this to be replaced.
If the worm bed is allowed to become dry, then the worms react as if there is going to be a drought (during which they could die of dehydration) and the frequency of mating increases stimulated by the instinct of survival of the species. Some growers use this method to accelerate the rate of population increase. They allow the bed to become dryer, over say seven days, and then re-wet it. However, my personal experience is that, if you keep your worms comfortable, they will breed well for you.
Bed temperature also has an influence on breeding frequency.
The rate varies markedly with temperature and virtually stops once it falls below 10°C or rises above 27°C. Worms are far more tolerant of cold than they are of heat, but freezing will kill them, as will temperatures over 30°C. I refer of course to bed temperature, not air temperature.
Rate of Population Increase
The rate of population increase exhibited by these three species, together with their rapid body growth, is the reason they arc classed as commercial. Collectively, in intensive cultivation you can expect a doubling of population in less than two months, providing bed conditions are maintained at a comfortable level.
