A hermaphrodite animal is an organism that has both male and female reproductive organs. This means that they can mate with any other individual of their species, regardless of gender. The most common type of hermaphrodite animal is a snail, but there are many others, including worms, slugs, and even some fish and amphibians.
The vast majority of hermaphrodite animals are sequential, meaning that they start as one gender and then change to the other at some point in their lives. However, there are a few rare cases of simultaneous hermaphrodites, which have both sets of reproductive organs from birth.
Hermaphrodite animals usually have two different mating strategies. They can either mate with another hermaphrodite, or they can mate with themselves.
Hermaphrodite animals often have unique reproductive organs. For example, some hermaphrodite snails have both testes and ovaries.
The reasons why some animals are hermaphrodite are still being studied, but there are several theories. One theory is that it helps the species survive and reproduce in difficult environments. For example, if there is a shortage of mates available, a hermaphrodite animal can mate with itself and produce offspring.
Another theory is that hermaphroditism provides a survival advantage by allowing animals to reproduce more quickly. In some species, it takes two individuals of different sexes to mate and produce offspring if both partners are hermaphrodites the species can multiply faster.
Examples of hermaphrodite animals include:
In many marine gastropods there are separate sexes (male and female); most terrestrial gastropods however are hermaphrodites
The love dart is the snails’ tool for maximizing their male side. It injects hormones to prevent the other snail’s body from killing newly introduced sperm once copulation begins.
When snails copulate, two penises enter two vaginal tracts. Both snails in a pairing transfer sperm, but whichever snail got in the best shot with the dart has a better chance of ultimately fertilizing eggs.
In some species, only one snail fires a love dart, but in others, like the garden snail, both do.
Worms are ‘hermaphrodites’ which means they have both male and female reproductive organs. When a worm is about 4 – 6 weeks old, a white band forms around their anterior (head). This is called a ‘clitellum’. The clitellum’ has both sets of organs in it, which means the worm is neither male nor female, but both.
Despite having both sets of organs, worms do need another worm to mate with. Worms join together with their heads facing in opposite directions and sperm is passed from one worm to another and stored in sacs.
Earthworms are hermaphrodites and have both male and female reproductive cells. They cannot self-fertilize, however, and must find a mate to exchange sperm cells with. Earthworms reach sexual maturity at about 4 weeks old.
Flatworms are the simplest of worm groups. There are about 20,000 species in this group. Flatworms are found in many places and can be free-living or parasitic. A parasite lives off another living thing called a host and can be harmful. One of the best-known flatworms is the tapeworm. Flatworms reproduce as hermaphrodites.
Slug, also known as a land slug, is a common name used for any terrestrial gastropod mollusk that doesn’t have a shell, has just a small internal shell, or a very reduced shell. Slugs have soft bodies, which is just one big muscle in the stomach area that can be used for almost all of their body functions.
Slugs belong to the class Gastropoda, which also contains snails. There are different families of slugs and often these families are not closely related even though they look similar, which can make their taxonomy seem quite confusing.
Slugs are invertebrates and do not have any bones in their bodies. They can easily dry out, and for this reason, they live in dark and damp habitats.
Slugs are hermaphrodites which means they have male and female reproductive organs. For this reason, they don’t need to find a mate to reproduce, although most do.
Once a slug has located a mate, they encircle each other, and sperm is exchanged through their protruded genitalia. A few days later, the slugs lay approximately thirty eggs in a hole in the ground, or under the cover of an object.
Slug eggs don’t have to hatch right away. They can remain dormant for years and hatch when the conditions are right.
Echinoderms are marine invertebrates. They include sea stars, sea cucumbers, sea urchins, and sand dollars. Some of the most well-known echinoderms are also hermaphrodites.
Some species of fish are hermaphrodites:
- Clownfish are all born male once they reach sexual maturity the most dominant males turn into females (a process known as sequential hermaphroditism).
- The giant grouper also known as the Queensland grouper, brindle grouper, or mottled-brown sea bass, is a species of fish from the subfamily Epinephelinae which is part of the family Serranidae. The family Serranidae also includes the anthias and sea basses. These fish are solitary animals and protogynous hermaphrodites.
- Ribbon moray eels have bright blue bodies with yellow jaws. They resemble Chinese dragons with their colorful appearance and high dorsal fins. They’re also suspected of being hermaphrodites that change from male to female as they age.