What is the Difference Between Semelparity and Iteroparity

The main difference between semelparity and iteroparity is that semelparity is a single reproductive episode before death. In contrast, iteroparity is the occurrence of multiple reproductive episodes before death in living organisms.  

Semelparity and iteroparity are two reproductive methods in living organisms. They differ by the number of reproductive episodes per lifetime.  

Key Areas Covered

1. What is Semelparity
– Definition, Facts, Examples
2. What is Iteroparity
– Definition, Facts, Examples
3. Similarities Between Semelparity and Iteroparity
– Outline of Common Features
4. Difference Between Semelparity and Iteroparity
– Comparison of Key Differences

Key Terms 

Big-Bang Reproduction, Continuous Iteroparity, Iteroparity, Semelparity, Seasonal Iteroparity

What is Semelparity

Semelparity is the occurrence of a single reproductive episode before death. Resourcing into maximum reproduction is the characteristic feature of semelparous organisms. Hence, it leads to the death of the parent organism after reproduction. Another name for semelparity is big-bang reproduction. A classic example of semelparity is the Pacific salmon, which lives many years in the ocean before swimming into the freshwater streams for spawning and dying. It also occurs in many insects, some butterflies, mayflies, many arachnids, and some mollusks, including octopus and squid.

Figure 1: Pacific Salmon

Furthermore, semelparity occurs in bony fish such as smelt and capelin. It also occurs in amphibians such as Hyla frogs, including the gladiator frog. It occurs in a few lizards, including Sceloporus bicanthalis of the high mountains of Mexico, Labord’s chameleon of southwestern Madagascar, and some species of Ichnotropis from the dry savanna of Africa. In mammals, semelparity occurs in dasyurid and didelphid marsupials. On the other hand, annual plants, including grain crops and domestic vegetables, are examples of semelparous plants. Century plants, some species of bamboo, and Lobelia telekii are also semelparous. 

What is Iteroparity

Iteroparity is the occurrence of several reproductive episodes before death. There are two types of iteroparity: continuous iteroparity and seasonal iteroparity. Continuous iteroparity occurs in primates, including chimpanzees and humans. Seasonal iteroparity occurs in birds and dogs. For example, humans can biologically reproduce many times throughout their lives. Other iteroparous vertebrates include virtually all mammals, all birds, most reptiles, and most fish. In invertebrates, most Mollusca and many insects such as cockroaches and mosquitoes are iteroparous.

Figure 2: Perennials

Moreover, most perennial plants are iteroparous. They are small flowering plants. They grow and bloom over spring and summer and die over autumn and winter. Also, they return from their rootstock in the spring. 

Similarities Between Semelparity and Iteroparity

• Semelparity and iteroparity are two reproductive methods of living organisms.
• They differ by number of reproductive cycles before death.

Difference Between Semelparity and Iteroparity

Definition

Semelparity refers to the occurrence of a single reproductive episode before death. In contrast, iteroparity refers to a reproductive strategy characterized by multiple reproductive cycles throughout a lifetime.

Reproduction

Organisms with semelparity reproduce one time in life, while organisms with iteroparity reproduce many times in life.

Plants

Annuals exhibit semelparity, while perennials exhibit iteroparity.

Examples

Pacific salmon, many insects, squid, octopus, and arachnids undergo semelparity, while humans, vertebrates, and most invertebrates undergo iteroparity.

Conclusion

In brief, semelparity and iteroparity are two reproductive methods with different reproductive cycles. Semelparity is the occurrence of a single reproductive cycle in life. It occurs in annual plants, pacific salmon, many insects, squid, octopus, and arachnids. In comparison, iteroparity is the reproductive method of having several reproductive cycles in life. It occurs in perennials, humans, vertebrates, and most invertebrates. Therefore, the main difference between semelparity and iteroparity is the number of reproductive cycles within the life cycle.  

References:

1. Hughes, P.W., Simons, A.M. The continuum between semelparity and iteroparity: plastic expression of parity in response to season length manipulation in Lobelia inflata. BMC Evol Biol14, 90 (2014).
2. Wikimedia Foundation. (2023j, June 28). Semelparity and iteroparity. Wikipedia.
3. Wikimedia Foundation. (2023k, July 2). Perennial plant. Wikipedia.

Image Courtesy:

1. “Oncorhynchus nerka 2” By David Menke – Own work (Public Domain) via Commons Wikimedia
2. “Cykoria podroznik pokroj” By Agnieszka Kwiecień – Own Work (CC-BY SA 3.0) via Commons Wikimedia