User:Grayzacc/Blue-spotted salamander

Reproduction
Eggs are laid in small agglomerations attached to twigs, rocks or plants at the edge of a woodland pond or ditch. Clutches average a dozen eggs, and females may lay up to 500 eggs yearly. Males and females first mate when two years old. Breeding occurs in early spring near vernal pools.

Eggs take about one month to hatch. At hatching, larvae have a well-developed mouth and eyes. Front limbs form at two weeks, and hind limbs form at three weeks. It will fully transform to its terrestrial state by late summer.

Blue-spotted salamanders are known to be associated with unisexual (all-female) populations of ancient origin. The unisexual females often look like blue-spotted salamanders but have hybrid genomes and require sperm from a co-occurring, related species to fertilize their eggs and initiate development. Usually the eggs then discard the sperm genome and develop asexually (i.e., gynogenesis, with premeiotic doubling); however, they may incorporate the genome from the sperm into the resulting offspring. Sperm incorporation commonly takes the form of genome addition (resulting in ploidy elevation in the offspring), or genome replacement, wherein one of the maternal genomes is discarded. This unique mode of reproduction has been termed kleptogenesis by Bogart and his colleagues.

A species complex between blue-spotted salamanders and Jefferson's salamander (Ambystoma jeffersonianum) is well-documented, extending from northeastern United States to eastern Canada.

Relationship with Tremblay's salamander
Female Tremblay's salamanders (Ambystoma tremblayi) breed with male blue-spotted salamanders from March to April. Eggs are laid singly or in small masses of 6 to 10 eggs on debris at pond bottom. The males' chromosome contribution only stimulates the egg's development; its genetic material is ignored.