Even though earthworms feel soft they are welled muscled and extremely strong.
The longitudinal muscle in earthworms is so strong that test worms have literally pulled themselves in two. The encircling muscle in each segment allow the earthworms to contract and expand along its length.
The setae are small spines which are projected from the body wall by muscles to act as anchors in the surface that the worm is moving along. The muscle can also retract the setae
The circular muscles contract and expand in co-ordination with the longitudinal muscle in series such as that if the posterior muscle are expanded and the anterior circular muscles are contracted the worm pushes and stretches its front end forward. The anterior muscles then expand to anchor its front end by use of the setae and the rear end is pulled forward. All this happens in a smooth and rhythmic motion.
At the very front end of earthworms in place of a nose is the prostomium, which when earthworms are underground it uses in conjunction with it’s co-ordinated hydraulic like muscle system to wedge its way between soil particles to dislodge them and consume them-if they are small enough-and form the worm burrow.
Tip: Earthworms anchor there posterior at the mouth of their tunnels at night for feeding and stretch to their limits to draw food to the hole. The less burrows are disturbed the more time the earthworms have for feeding, excreting and growing.
How Do Earthworms Move
Life Cycle Of Earthworms
Earthworms will accelerate breeding to continue the species with th onset of drought or extreme cold of winter. Breeding ceases in hot dry soils.
Under favorable temperature and moisture conditions they will breed up to consume the food supply.They abhor a vacume. The more earthworms in a favorable situation the more mating and the more young. Earthworms eggs will hatch with the onset of spring. Growth and activity peak as summer approaches. They will lay ample eggs to survive drought.
Earthworms reach age at 2 to 3 months and full maturity at around 12 months. The live for about 2 years under good conditions, although healthy earthworms up to 15 years old and beyond have been observed. Because mature worms can produce a capsule in just over a week and from which will hatch between 2 and 20 young earthworms two or three weeks. One pair of earthworms under ideal conditions can breed up to 1500 young in 12 months. In general the more mature the worm the better the breeder it is.
Earthworms avoid extreme hot or cold temperatures and will burrow deeper in summer and winter. So deep in fact you may believe you have lost your worm population. Breeding rates have been found to vary according to food types. As a general rule the higher the nitrogen content of the food the higher the breeding rate especially in mature earthworms.
- Tip: Best breeding conditions are under garden of farm irrigation or controlled climate beds.
- Tip: Keep your soils loose and not compact so that worms can travel to the depths. Maintain vegetable cover during summer to insulate the soil. Cover worm beds with an insulating matting.
Reproduction For Earthworms
Earthworms do three things well and often. Eat, excrete and reproduce.
One pair of mature earthworms can multiple to up to 1500 in a year under ideal conditions of soil temperature, food supply and moisture. Earthworms are hermaphrodites. That is each partner can produce young from the mating process.
The sex organs are at the anterior end. They are:
- Two pairs of testes-male sex glands where male cells are formed.
- Testes sac which surround the testes.
- Seminal vesicles-sperm sacs where male cells lodge and start to develop and then pass back to the testes sac and through-
- The seminal funnels and sperm ducts to the two male genital openings on the bottom surface of the worm.
- Two pairs of seminal receptacle sacs are open to the lower surface during mating to receive the sperm from the mating worm. This is a two way exchange.
- Eggs are formed in the two ovaries from where upon maturity they pass out through the-
- Two ovary funnels and two oviducts on the ventral or lower surface of the worm after storage in the two ovary sacs.
Earthworms-Mating and Fertilisation
During mating two earthworms are bonded together by a mucous like excretion from each others clitellum gland. This bonding enables the exchange of seminal fluids which pass from the donor worm sperm ducts to the seminal receptacles for storage and the next phase. Each partner acts as a male donor and exchanges sperm. The worms then separate.
The clitellum glands come in to play again when they form a mucous ring which gradually slided forward over the body. Several eggs pass out of the oviduct and lodge in this ring. As the ring passes the seminal receptacles it receives the sperm stored from the previous mating. Fertilization takes place outside the earthworms body within the mucous ring.
The ring then passes forward and seals both ends as it slips off the earthworms front end. The egg or capsule then lies in the surrounding soil.
The capsule is 2 to 5mm across depending upon the species. They turn from greenish yellow when laid to brown when they are about to hatch after two or three weeks. They contain between two and twenty young earthworms.