Skip to content

Hermaphroditic animals: reproduction and examples

Have you heard of hermaphroditic animals or that they have both reproductive systems? Did you know that it can be a permanent trait or something changeable? Actually, hermaphroditic animals have a reproduction with certainly peculiar characteristics.

If you want to know what they consist of and see some species that have this reproductive characteristic, we recommend this AgroCorrn article. Next, discover hermaphroditic animals, their reproduction and examples of species.

What are hermaphroditic animals

In the animal kingdom two basic types of reproduction are distinguished: asexual, without exchange of genetic material between individuals, and sexual, with the formation of female and male gametes that carry half of the genes of their respective parents. Within sexual reproduction , we find a modality that is hermaphroditic reproduction . In this case, gametes are formed, but the same individual can give rise to female-type and male-type gametes , for which they will have two well-differentiated reproductive systems (female and male respectively).

Within hermaphroditism we also find permanent or simultaneous hermaphroditism and sequential hermaphroditism. In this last variant, the same individual has different reproductive organs throughout their life cycle. Some fish are capable of making this change.

Hermaphroditism usually occurs in solitary animals for which it is difficult to locate potential mates. This occurs for example in worms, which are buried in a volume of soil, with little possibility of communication with their peers. Thus, when luck is favorable for an encounter, the species ensures that it yields two viable fertilized individuals.

Reproduction of hermaphroditic animals

The reproduction of hermaphroditic animals can include complex courtships, as in the case of snails. In addition, it is usually an external fertilization , in which the male and female gametes are released to the environment, where fertilization occurs.

Some are helped by the generation of “spermatophores”, a sac-like structure that contains a mass of sperm wrapped in a covering. This protective covering can also include various nutrients.

Difference between cross-fertilization and self-fertilization

The hermaphrodites can fertilize their gametes in two different ways:

  • Cross fertilization: requires two individuals that exchange their male and female gametes simultaneously. This is the case, for example, of snails.
  • Self-fertilization: in this case, the individual himself can join his female and male gametes to generate new individuals.

Beyond the obvious differences in the number of individuals involved in fertilization, there is a clear effect on genetic variability. The main advantage of sexual reproduction over asexual is the greater genetic variability that is generated, which allows both avoiding diseases due to consanguinity and forming a more variable population that can better adapt to changes in its environment. With the cross-fertilization strategy, this variability continues to be maintained.

But is self-fertilization equivalent to asexual reproduction? No, it is not. During the formation of gametes (or gametogenesis) there is a process of crossing over in the chromosomes of the individual, which gives rise to new combinations of genes. Thus, the variability produced by this variant is halfway between the variability generated by asexual reproduction and by canonical sexual reproduction. Let us also not forget that mutations can be the source of new alleles (variants of the same gene).

Hermaphroditic animals: examples

Is hermaphroditism a common feature? No, most species have male or female individuals, whose sex is defined by their chromosomal endowment (not their gender). However, we can find some examples of well-known hermaphrodite animals in nature:

Snails

Some species of snails are hermaphrodites; in any case, all hermaphroditic snails are dependent on cross fertilization. The coupling between two individuals can last several hours and consists of two processes: first they launch a structure in the form of a “dart” that contains stimulating secretions. Once the two snails are receptive, they emit a spermatophore, a structure that contains the sperm that accesses the cavity where the female gametes are located. The laying usually comprises about five eggs.

Guppy fish

The guppy fish is a good example of sequential hermaphroditism. Depending on the environmental conditions (mainly the ratio between males and females around it), the guppy fish is capable of changing its sex. This requires important changes in the expression of genetic material and remodeling of body structures.

Other hermaphroditic animals

  • Sea stars.
  • Ofiuras.
  • You had.
  • Frogs
  • Trematodes.
  • Worms
  • Flat worms.
  • Slugs
  • Leeches.
  • Clownfish.
  • Cleaner lordo fish.
  • Old fish.
  • Pale serrano fish.
  • Julia fish, maiden or budion.
  • Snout wrasse.
  • Golden.
  • Hawkfish.
  • Shrimp.
  • Scallops
  • Varieties.
  • Oysters
  • Slugs or sea dancers.
  • Sea sponge .
  • Limpets
  • Corals
  • Fresh water hydra.
  • Anemones
  • Fresh water hydras.

The seahorse is an externally fertilized animal, but is it a hermaphrodite?

Although it is not strictly hermaphroditic , there are some animals that reproduce far from the typical male-female patterns.

In the seahorse species , the male releases seminal fluid into the environment. The female then begins to transfer the oocytes to the male’s abdominal sac through an ovipositor organ. During this transfer, fertilization takes place (therefore, the seahorse is an animal with external fertilization ). The embryos reach the cavity of the male and develop there until the eggs hatch and the juveniles emerge.

Hello, I am a blogger specialized in environmental, health and scientific dissemination issues in general. The best way to define myself as a blogger is by reading my texts, so I encourage you to do so. Above all, if you are interested in staying up to date and reflecting on these issues, both on a practical and informative level.

Leave a Reply

Your email address will not be published.