Last week, while we were cleaning, feeding, and doing a health check on the resident jumping spider at DJL Exotics, we noticed something odd. Our jumping spider was guarding a specific area that was outside of their usual resting spot. On closer inspection, we noticed that the jumping spider was guarding an egg sac. So we learned two things that day:
- Our jumping spider was female.
- Jumping spiders are capable of parthenogenesis.
In this article, we’ll talk about parthenogenesis and the advantages/disadvantages of the practice in species.
What is Parthenogenesis?
Parthenogenesis is a system of reproduction where the female doesn’t utilise a male to produce offspring. Essentially the growth and development of the embryo is completed without fertilisation as you would expect.
It can occur in a wide variety of species including in plants, vertebrates, and invertebrates. In many cases, the offspring developed through parthenogenesis are exact clones of the mother, though this is not always the case. Those that are clones of the parent have been developed through apomictic parthenogenesis.
Those that are developed through automictic parthenogenesis will have differences between similarly conceived offspring as well as the mother. Various methods can cause automictic parthenogenesis.
Why is Parthenogenesis Used?
One of the advantages of sexual reproduction is the combination of traits to create offspring that should outperform their parents. With asexual reproduction, or apomictic parthenogenesis, offspring are exact clones of the mother, so no evolutionary process is going to occur.
However, there are some advantages of parthenogenesis.
- Protects species from the transmission of diseases that can occur during sexual reproduction.
- Saves time/energy finding a mate.
- Researchers believe that parthenogenesis can speed up population growth.
- It helps to create genetic stability.
However, there are some disadvantages too.
- It doesn’t favour long-term survival in an ever-changing world. If one gene or trait is unsuitable for the environment, then it can cause a population crash.
- Limited protection against deadly pathogens.
Are There Species That Only Produce Through Parthenogenesis?
Many species can produce through a mixture of parthenogenesis and sexual reproduction. For example, komodo dragons can utilise both, with one from London Zoo having switched between the two reproduction methods.
Yet some species can only produce this way. For example, Mourning Geckos are a female-only species (technically there are some males produced, but these are very rare and often sterile). Three types of house geckos are also known to exclusively produce this way.
Some snakes can do this. The brahminy blindsnake is the only one that is known to be an all-female species.
Of course, the benefit of all these species is that they find it easier to move to new environments. With many of the species hitching rides with exports to new areas.
Final Word: Parthenogenesis: An Interesting Way to Reproduce
Parthenogenesis is an interesting way for animals to reproduce. It is rare, however, it can help some species to survive. We will see how our jumping spider eggs get on.
