The species of such fishes have high and early mortality. The fry hatching of such eggs generally has different shapes from adults, which leads to the planktonic life. The diameter of the eggs of the fishes is very small as compared to the length of the body of the parent but they are several in numbers. The most fecund group of the animals is the marine teleosts. The type III represents the early mortality, but the high rate of subsequent survival. The type II is the straight line which represents the constant mortality rate from birth to maximum age. The type I is when the mortality is concentrated towards the end of the maximum lifespan. The type of the survivorship curve reflects the characteristics of the life cycle of the species in the stable population. The survivorship curve of the species population influences under the strong climatic conditions or the other environmental conditions may fluctuate between the II- type and III-type. The curve also depends on the conditions whether the population occupies the favorable habitat or on the fringe of the distribution of the species. The survivorship curve is the reflection of population dynamics, which represents the shape of species is different between the increasing and decreasing phase of the population. The survivorship curve is mostly affected by the external factors that is responsible for the change in the survivorship curve. While the life expectancy is more as they develop and transform into adults. The mortality rate of fishes is more in the early stages. This results in the different shape and type of the survivorship curve. The survival rate of different species is different.

The type A, type B, and type C is of a convex, diagonal, and concave shape, respectively. The survivorship curve is of three types. The survivorship curve was developed by Pearl in 1928.

Survivorship curves coursenotes biology