Photo Observation of the Month of February - Port Jackson Shark

Who doesn't love a good shark photo? We have now completed our fourth month of the Marine Biodiversity of Southern Sydney Harbour project and I'd like to congratulate user eschlogl (once again!) for his Photo Observation of the Month of a Port Jackson Shark (Heterodontus portusjacksoni) from Camp Cove. Despite being an avid diver in Sydney for 25 years, this is the first time Erik observed juvenile Port Jackson Sharks here. Port Jackson Sharks usually live in rocky environments on, or near, the sandy/muddy bottom. In some instances they may be resting ajacent to seagrass meadows. This species occurs in southern Australian waters from southern Queensland south to Tasmania and west to the central coast of Western Australia. In fact, genetic studies suggest that there may be two populations in Australia, one occurring from southern Queensland to New South Wales and the second from north-eastern Victoria to Western Australia. These sharks have an oviparous reproductive mode, meaning that they lay eggs, in this case dark brown spiral egg cases that hatch after approximately one year. The female actually manipulates the egg case in her mouth once laid to attach it to rocks and crevices in order to anchor it in place. This species is not to be confused with the the Crested Hornshark (Heterodontus galeatus), which has large prominent crests above the eyes and lacks dark markings on its side.
This journal post was written by project leader and iNaturalist member, Dr Joseph DiBattista.
由使用者 joseph_dibattista joseph_dibattista2023年03月01日 01:42 所貼文




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