This article, titled “17 Examples of Semelparous Animals,” explores the fascinating phenomenon of semelparity in the animal kingdom. Semelparous animals are those that reproduce only once in their lifetime, after which they die. This is in contrast to iteroparity, where organisms reproduce multiple times over their lifetimes. The article provides a diverse range of examples, from the Pacific salmon, which return to freshwater streams to spawn before dying, to the male antechinus, which mates until it exhausts itself to death. From insects to spiders, reptiles to mammals, the article showcases the wide variety of semelparous animals and their unique reproductive strategies.
17 Examples of Semelparous Animals
Semelparous animals are those that reproduce only once in their lifetime. Then, after they have mated or produced offspring, they die. Sometimes it only occurs in males in specific species. Semelparity is also called big-bang reproduction. This is in contrast to iteroparity, where an organism reproduces multiple times over the course of its lifetime. This article explores 17 examples of semelparous animals.
1. Pacific Salmon
Pacific salmon are semelparous anadromous fish that return to freshwater streams to spawn after living most of their lives in the ocean. Spawning takes place in late summer or early fall. After spawning, all pacific salmon die, making them truly semelparous. The female lays her eggs in a nest that she has dug out with her tail, and the male fertilizes them externally.
Found in Australia, the kaluta is a small marsupial with a very short lifespan. Females can store the sperm of several mates. Males die almost immediately after mating, making them semelparous.
Both male and female octopuses are semelparous. After mating, males will literally stop eating and starve to death. Females will lay their eggs and stay nearby for protection but also starve to death after reproducing.
4. Praying Mantis
For praying mantises, only the males are semelparous. Once a male mantis has mated with a female, she will decapitate him. This gives him one shot at reproduction in his life, making him semelparous. Occasionally, male mantises can wrestle away from a female trying to take his head off. It’s a rare occurrence, but some males do survive mating.
5. Australian Redback Spider
The Australian redback spider is a species of spider that is semelparous. After mating, the male redback spider will die. The female will continue to live for another two to three years. She will produce several more egg sacs.
6. Black Widow Spider
The black widow spider is a well-known example of a semelparous animal. After all, it gets its name from the fact that the males die after mating. After the female black widow spider mates, she will feed on her mate. Male black widows never survive reproduction.
7. Slender Opossum
Slender opossums are small, South American marsupials. They are semelparous in both males and females. All slender opossums die after mating. Slender opossums have a short life cycle and a high reproductive potential. They reach sexual maturity quickly and produce large litters of offspring.
8. Trans-Volcanic Bunchgrass Lizard
Native to Mexico, the trans-volcanic bunchgrass lizard is an example of a semelparous lizard. Interestingly, females die before males. Males can live a few months longer than females. The trans-volcanic bunchgrass lizard is a short-lived species. Most individuals only live for one to two years.
The antechinus is a semelparous animal native to Australia. Males will literally mate themselves to death. During mating, male antechinus will not eat or do anything else. They mate until they die. Some mating encounters can last up to 14 hours straight. Male antechinus will exhaust himself, losing fur and wearing itself out to the point of death.
10. Labord’s Chameleon
A native of Madagascar, Labord’s chameleons are a prime example of semelparous animals. With a lifespan of only 4 to 5 months, Labord’s chameleon has the shortest lifespan of any four-legged vertebrate. After mating, the female Labord’s chameleon will lay a clutch of eggs, and the whole population, males and females, die. The population returns upon the hatching of eggs.
11. Sockeye Salmon
Sockeye salmon are found in the northern Pacific Ocean and in freshwater lakes and rivers throughout much of western North America. They swim up freshwater streams to spawn. When they return to freshwater to spawn, they stop feeding and begin to store energy in their body for the journey upstream. Sockeye salmon will die once they have spawned.
12. Desert Spider
The desert spider that lives in North America is semelparous. Experiments conducted on these spiders found that females who remained with their egg clutch died. When researchers removed the egg clutch, the female spider laid more eggs and did not die immediately. These experiments are ongoing, and there’s still a lot to learn about semelparity in desert spiders.
13. Brush-tailed Phascogale
The brush-tailed phascogale is a small marsupial that is found in Australia. The males of this species are semelparous and die after mating. Males have a very high level of testosterone, which makes them aggressive and territorial. They also have a high level of stress hormones, which can lead to their death.
14. Dark Fishing Spider
This spider gets its name from its dark coloration and its habit of fishing for prey in the water. Like many other spiders, females in this species eat their mates, making the males semelparous. Dark fishing spider females create nursery webs for their eggs near water. They lay over a thousand eggs in one egg sac.
Mayflies are insects with a fascinating life cycle that are semelparous. During their short lifespan, adult mayflies mate and lay eggs, which hatch into nymphs or larvae. These nymphs live in freshwater environments and go through several molts before emerging as adults. Once they emerge, they don’t eat. Their sole purpose is to mate and lay eggs. Then they die.
Cicadas are a type of semelparous insect found all around the world. They spend most of their lives as nymphs. They can spend over 10 years in the ground in their nymph stage. When they emerge as adults, the cicada’s only mission is to mate. Males stay in one location to call females to mate. Once they have mated, their life cycle has completed and both males and females die shortly after.
The quoll is a carnivorous marsupial found in Australia and New Zealand. They are the largest semelparous animal in the world. Female quolls mate with multiple partners to increase the chances of genetic diversity. Male quolls only survive one mating season and die after mating.