Do Earthworms lay eggs?
Yes, earthworms do lay eggs. They lay eggs inside the cocoons which get thrown off the head of the earthworm later after copulation had occurred between the two individual earthworms.
We all know that earthworms have both male and female sex organs on the same body, meaning that they are bisexual without having separate male and female individuals.
So, every individual earthworm is capable of producing both male and female gametes. But, still self-fertilization doesn’t occur that is the same individual cannot copulate and fertilize itself.
So, cross-fertilization occurs between two different worms, where both can copulate (mate) with each other and mutually interchange the sperms.
That is, during copulation the sperm of one worm is transferred into the other and vice-versa. The sperms are then be stored inside the spermathecae of both of the worms.
After this mutual interchange of sperms, the two worms separate and lay their eggs in the cocoons.
The fertilization and further development of the eggs take place outside of the earthworm’s body which is inside the cocoon once it is laid.
The fertilization occurs after the cocoon with the egg inside has been deposited in a moist place.
The cocoon formation in the majority of the well-known species usually takes place in the summer season, especially during and after the monsoon.
So, Do Earthworms lay eggs? Yes, they lay eggs inside a protective covering of the cocoons.
Do Earthworms give birth to young ones? No, earthworms don’t give birth to young ones. They do lay eggs that develop outside the body of the earthworm and hatches into young earthworms.
How many eggs do Earthworms lay? How often do worms lay eggs?
How many eggs do Earthworms lay? During favorable conditions, earthworms can lay between 14 to 6 cocoons per month. Each of the cocoons can contain about 4 to 20 eggs.
So, multiple young earthworms between 20 to 120 can hatch out of the cocoons per month. Their hatching depends on the season, temperature, and humidity levels.
The cocoons with the eggs remain in a state of diapause (a period of suspended development) and will continue to hatch months later.
The eggs can enter a state of diapause because the tough capsules of the cocoons ensure the survival and protection of the eggs in very harsh conditions that would kill adult earthworms.
So, after the diapause phase has been completed and as the harsh environmental conditions get over, the young earthworms will soon develop and will hatch.
The young worms that got hatched will mature and will start reproducing in approximately 2 to 3 months.
How often do worms lay eggs? Earthworms can lay eggs for 2 to 3 days after every 27 to 30 days time period. Some species can even lay eggs after every 7 to 10 days.
Earthworms have a very fast and rapid reproduction and breeding power that allows them to just double in population after every 50 to 60 days time period.
In some species, it has been also seen that a population of earthworms doubles after every 3 to 6 months time period.
While under very ideal conditions a few as 8 earthworms can become 1,000 to 1,500 earthworms in only about 6 months.
The eggs will hatch faster and better at warmer temperatures when the soil temperature is 26°C.
How do Earthworms lay eggs? – (The Process of Laying Eggs in Earthworm)
When the mutual interchange of sperms that is soon after the copulation (mating) has been completed, the two worms will eventually separate and will later lay the eggs in multiple numbers with the cocoons covering those eggs.
After mating, the earthworm will prepare itself to lay eggs by secreting cocoon layer as a viscid and gelatinous substance by the clitellar glands, forming a broad membranous band around the clitellum.
This cocoon layer hardens into a tough elastic tube forming the cocoon or egg capsule. This hard tube (cocoon) is what that protects the soft eggs inside.
A slime tube will also be secreted by the epidermal mucosal cells of the clitellum over the cocoon.
As the earthworm starts to wriggle behind, the slime tube and cocoon get slipped over the head.
On its way during the slip, the cocoon receives the ova from the female genital aperture and the sperms of the other worm that was stored from the spermathecae.
An albuminous fluid is also deposited inside the cocoon by the glands of the anterior segments of the body.
This fluid gives the cocoon a bright golden yellow color when laid. The cocoons progressively turn brownish red before hatching.
Collecting the gametes, the slime tube and cocoon comes out by slipping over the head of the earthworm.
As the cocoon comes out, the ova and the sperms get fertilized inside the cocoon outside the body of the earthworm. Thus, cross-fertilization takes place and the zygote is formed inside the cocoon.
That’s how earthworms do lay the eggs inside the cocoons. Many cocoons may be formed in succession after each mating session.
Where do earthworms lay eggs?
Earthworms will lay their eggs deep inside the damp and moist soil where the soil temperature is at least between 14°C to 26°C. The eggs usually prefer a temperature of 24°C to 26°C to hatch.
Earthworms lay egg capsules in the soil usually near a good source of food. The eggs hatch faster at warmer temperatures than what adult worms prefer.
As the young little worms hatch out, they look like tiny versions of the adults and they begin to feed on both organic matter, small microorganisms, algae, fungi, and bacteria deep inside the soil, and begin to grow rapidly.
The young ones don’t generally come out to the surface of the soil and prefer better to stay inside hiding in the soil.
Just like adults they come out only at night and are often seen feeding above the soil surface.
Similar to adults earthworms, they must keep their body surface wet to respire, so they do avoid sunlight and prefer damp moist soil.
The eggs that are in very cold or hot and dry climates may go dormant when it is too cold or dry. They will only hatch under favorable conditions.
It is also to be noted that the newly hatched young earthworms receive no parental care and resembles the adult except for size and absence of clitellum.
How to identify earthworm eggs in soil?
The color of the eggs is actually transparent that remain mostly covered inside a bright golden yellow colored cocoon.
The eggs of some species can be like white colored globules that are of the same size as the head of the pin.
The cocoons are generally 0.8 mm to 1 cm in size. They can also have a light amber color, which is commonly found in a range of yellow-orange-brown-red colors; likewise as a color amber can refer to a range of yellow-orange colors.
Earthworm eggs are generally white when they are new and turn amber or bright golden yellow in color soon after several hours.
The shape of the cocoon is also a thing to notice. Earthworm cocoons generally look like small lemons, although some can be rounded with tapering ends, or some are tetrapod shaped.
The actual eggs hatch inside the amber colored cocoon, and the cocoon itself becomes a protective covering for the baby worms inside.
It is also to be noted that the cocoons progressively turn brownish red before hatching.