Mottled Sculpin - Life History

Life History

Mottled sculpin reach sexual maturity at the age of two. The breeding season for mottled sculpin is during April and May. At the beginning of the season the males will take refuge under flat-bottomed rocks, waterlogged wood or other rubble found in stream beds. In order to mate the female will come up to the males nest and lay her eggs there. The female chooses her mate on physical attributes. Since larger males pick out nesting sites with better resources qualities, the female’s choice of the largest male indicates she is picking good genes in a mate and also a good environment for her young to grow up After mating she either leaves or is chased away by the male. The males do this because females will eat the eggs right after spawning if the male does not run her off. The males continue to protect the eggs until they have absorbed their yolk sac and are ready to distribute themselves.

Mottled sculpins only mate once a year. The clutch size can vary anywhere from 8 eggs to 148 eggs for females. However within that year one male could mate with ten or more females This leads to very large nest sizes. One study looked at twelve different nesting sites within a year and found that one nest can have anywhere from 54 to 1587 eggs with an average of 744 eggs per nest. Mottled sculpin’s average life span is to age six.