Hida Salamander (Hynobius kimurae) eggs sleeves

How about an aspect of the reproductive biology of a very cool Japanese salamander that few people actually get to see? – the “egg sleeve.” The Hida Salamander (Hynobius kimurae) deposits its eggs in pairs of sleeves (one sleeve from each oviduct), or egg cases, containing 8 to 25 eggs per sleeve. The egg sleeves are attached to the bottom of rocks below the water in streams. The eggs hatch and the first few days to several weeks, after hatching, are spent within the egg sleeve. The sleeve gradually breaks down and the larvae escape out into the waters of the stream where they will finish development. Egg sleeves are unique to the Hynobiid salamanders. These eggs sleeves were photographed in Tottori Prefecture, Japan (2007).