Pacific Giant Salamanders: Dicamptodontidae

Adult Pacific giant salamanders are active at night, but sometimes they are found walking by day in dark, moist forests. Large Pacific giant salamanders can be aggressive, head butting and tail-lashing one another and inflicting severe bites to defend themselves from predators. Adult Pacific giant salamanders bark sharply, but scientists do not know why they make this sound.

Scientists are not sure how Pacific giant salamanders mate. They do know that the males place sacs of sperm on land and that fertilization (FUR-teh-lih-ZAY-shun), the joining of egg and sperm to start development, takes place inside the female's body. The females lay eggs one at a time in groups of eighty or more under large rocks and logs. The fertilized (FUR-teh-lyzed) eggs develop slowly, and hatching does not occur for many weeks. Newly hatched larvae probably do not feed for several weeks. Metamorphosis takes at least two years and sometimes as long as four years. Some Pacific giant salamanders do not go through metamorphosis; they keep the body forms they have as larvae. However, their reproductive organs mature, and they can breed.