What are worms, and how do worms reproduce? Like every living thing, worms reproduce to keep their species alive.
Worms are invertebrates with elongated bodies lacking limbs.
They comprise five major groups: annelid, flatworms, spiny-headed worms, aschelminth, and ribbon worms.
These major groups of worms vary significantly in their size, inhabitants, what they feed on, their lifecycles, and how they reproduce.
The earthworm is the most commonly known worm from the group of annelids.
Just like every other worm, earthworms are simple species with gut, a mouth, anus and no eyes.
They are not like other advanced creatures that have brains and nerves.
Worms generally lack most features found in advanced animals.
How Do Worms Reproduce?
Worms reproduce based on their species, and there are various ways by which worms reproduce. The following is the reproduction of five groups of worms:
Annelids
Annelids are the organisms that belong to the phylum Annelida. They live in many different places, including the soil, freshwater and saltwater environments. An example of an annelid is the earthworm, which is the most commonly known.
Annelids may reproduce sexually or asexually; it depends on the species. For instance, earthworms are hermaphrodites, meaning they have both the male and female reproductive system. However, this does not mean that they can fertilize themselves.
They reproduce by meeting up facing opposite directions before they swap sperm. This sperm is collected by a cocoon of mucus that works its way up the outside of the worm’s body.
This is where that worm’s eggs are collected and fertilized, and then the cocoon ends up in the soil, where the future worms-to-be develop.
In contrast, the polychaetes (annelids) reproduce asexually. They can reproduce by fission. This means they can make an exact copy of their DNA and then split it. They primarily clone themselves into a new organism.
Also, they can reproduce by budding. This allows them to break off little fragments of themselves. These fragments possess the exact DNA as the “parent” worm to form a new organism.
However, this new organism will not be the same size as the parent at first, but it will eventually grow into the adult size.
Flatworms
Flatworms, also known as Platyhelminthes, are species of nonparasitic and aquatic organisms. Flatworms are generally hermaphroditic, yet they reproduce sexually and asexually, depending on the species.
They reproduce asexually by fission and budding. Fission is also known as fragmentation or cloning. This occurs when flatworms make an exact copy of the parent’s DNA and then split into two to form a new organism. Budding happens when flatworms break off little parts of them to regenerate into a new organism.
There are many ways a flatworm can reproduce sexually. Flatworms are hermaphroditic, and they also can self-fertilize. They can also produce eggs within themselves and fertilize them with the sperm produced in their bodies.
Flatworms can also reproduce sexually through mating. They would make physical contact with fellow flatworms, and the sperm of one is absorbed into the skin of the other.
The fertilized eggs become encased in a cocoon inside the mother’s body before being released into environments. The eggs are nourished inside the cocoon until they are ready to hatch.
Roundworms
Roundworms, also known as Nematodes or aschelminth, are parasitic and nonparasitic species. They are majorly hermaphroditic and gender-specific.
They reproduce majorly by sexual reproduction. Gender-specific roundworms reproduce by copulation, while hermaphroditic roundworms fertilize their eggs by the sperm produced in their bodies.
Some species of roundworms give birth to their young ones alive. At the same time, most species release their fertilized eggs into various environments. These eggs develop into larvae and go through the metamorphosis particular to their species.
Ribbon Worms
Ribbon worms are generally gender-specific, and they reproduce sexually. During mating, the eggs and sperm are released individually, and th eggs are fertilized outside the body. Also, their reproduction depends on the species.
Some species are gender-specific, while others are hermaphroditic. Some species also reproduce asexually. This is due to their ability to regenerate lost or tampered body parts.
When a part or parts of them break up, ribbon worms can regenerate those parts and be whole again. Because the lost parts contain the DNA of the parent, they form and grow into a new organism.
Spiny-headed Worm
Spiny-headed worms, also known as acanthocephalan, are known to be parasitic. This worm reproduces sexually, and since it is parasitic, mating happens in the guts of their host.
The male and the female spiny-headed worm copulate, and the fertilized eggs are removed along with the faeces of the host.
The fertilized eggs do not develop any further until they are ingested by another host. In the host’s gut, the larva becomes encased and develop into a new stage. The development continues until the adult stage.
Worms reproduce differently, depending on their species. Sometimes, the simple things in nature can catch the attention of the most brilliant minds around us.
We always want to know how things are the way they are and why they work the way they do. How worms reproduce is one of nature’s fascinating feat.
Sources;
- Earthworm – Wikipedia
- How Do Flatworms & Roundworms Reproduce? – Sciencing
- Ribbon worm – Britannica
