82. Among the following which is not an characteristic of r-Selected species-
    (1) Early sexual maturity (2) Short life span
    (3) Small size of offspring’s (4) Iteroperity

r-selected-species-characteristics-iteroparity

Introduction

In ecology, r-selected species are known for their fast-paced life strategies. They thrive in unpredictable environments by reproducing quickly and in large numbers, with little investment in each offspring. But not every reproductive trait fits the r-selection mold. Let’s explore which characteristic is not typical of r-selected species and why.

Core Characteristics of r-Selected Species

r-Selected species are adapted to environments where resources are unpredictable and mortality is often high. Their evolutionary strategy is to maximize reproductive output, ensuring that at least some offspring survive to adulthood. Here are the classic traits:

(1) Early Sexual Maturity

• Typical of r-selected species.

• These species mature quickly, allowing them to reproduce soon after birth and take advantage of temporary resources.

(2) Short Life Span

• Typical of r-selected species.

• r-Selected organisms often have brief lifespans, focusing on rapid growth and reproduction rather than longevity.

(3) Small Size of Offspring

• Typical of r-selected species.

• Producing many small offspring allows for rapid population increases, even if individual survival rates are low.

(4) Iteroparity

• Not typical of r-selected species.

• Iteroparity means reproducing multiple times over a lifetime. While some r-selected species can be iteroparous, the classic r-selected strategy is actually semelparity—reproducing once in a massive burst and then dying (think of annual plants or many insects).

• Iteroparity is more commonly associated with K-selected species, which invest in fewer, larger offspring and reproduce over many seasons.

Why Iteroparity Is Not a Classic r-Selected Trait

• Semelparity (one-time, massive reproduction) is efficient in unstable environments, maximizing the chance that some offspring will survive unpredictable conditions.

• Iteroparity is favored in more stable environments, where repeated reproduction increases the chance of offspring survival over time.

Examples

• r-Selected, Semelparous: Many insects (like mayflies), annual plants, some fish (like Pacific salmon).

• K-Selected, Iteroparous: Elephants, humans, many birds and mammals.

Quick Comparison Table

Conclusion

Iteroparity is not a typical characteristic of r-selected species. While r-selected organisms focus on rapid, high-volume reproduction—often in a single, explosive event—iteroparity is more aligned with K-selected species that reproduce multiple times and invest more in each offspring.

Correct answer:
(4) Iteroparity