Not much is known about the capability of different peacock spiders species to interbreed, but there is at least one experiment in that regard by Jurgen Otto. Maratus avibus and Maratus caeruleus are two peacock spiders that are similar in appearance and undoubtedly very closely related. Maratus avibus lives on the Australian mainland and Maratus caeruleus on a small island about 8 km away from where Maratus avibus lives. It is likely that the two species had a common ancestor about 10000 years ago when the island was connected to the mainland, and after sea levels rose that population became separated and two species evolved. In the laboratory it was possible for Maratus caeruleus females to mate with Maratus avibus male and to produce viable hybrids. However, after mating with hybrid males, the two hybrid females from that study, did not produce viable eggs. This suggests that some genetic reproductive barrier exists between these species.