The critically endangered Spotted Handfish is an iconic species found in the Derwent estuary, Tasmania. They are small, only growing to a maximum size of 12 cm. Each fish is covered with spots or stripes, in patterns unique to each individual. The spotted handfish has overgrown pectoral fins which look like hands, which they use to slowly walk on the sandy sediment where they hunt for small crustaceans and worms. Fewer than 10 colonies exist within the Derwent estuary. Spawning occurs from September to October, during which freshly laid egg masses are attached to substrate living on the sea floor such as sponges, seaweeds and particularly sea tulips (ascidians).
The principle threat to spotted handfish appears to be reduced abundance and distribution of spawning substrate to attach egg masses – particularly the stalked ascidian, which has been heavily preyed upon by the invasive northern Pacific seastar. In the absence of spawning substrate, eggs laid by spotted handfish are swept away in the current, and females cannot effectively guard their egg masses to ensure that they hatch successfully. Poor recruitment of young fish will lead to the eventual extinction of colonies. Due to the speed of their decline in range and abundance the spotted handfish became the first marine fish to be listed as endangered under the Federal Environment Protection and Biodiversity Protection Act 1999, and was followed by state protection under Tasmania’s Threatened Species Protection Act 1995.
This image was captured in the Derwent estuary off Nutgrove Beach (2023). The handfish will normally remain still and let you take a few photos. But come mating season they dash about on the seabed floor with lightning speed, making it very difficult to capture an image of them.
The critically endangered Spotted Handfish is an iconic species found in the Derwent estuary, Tasmania. They are small, only growing to a maximum size of 12 cm. Each fish is covered with spots or stripes, in patterns unique to each individual. The spotted handfish has overgrown pectoral fins which look like hands, which they use to slowly walk on the sandy sediment where they hunt for small crustaceans and worms. Fewer than 10 colonies exist within the Derwent estuary. Spawning occurs from September to October, during which freshly laid egg masses are attached to substrate living on the sea floor such as sponges, seaweeds and particularly sea tulips (ascidians).
The principle threat to spotted handfish appears to be reduced abundance and distribution of spawning substrate to attach egg masses – particularly the stalked ascidian, which has been heavily preyed upon by the invasive northern Pacific seastar. In the absence of spawning substrate, eggs laid by spotted handfish are swept away in the current, and females cannot effectively guard their egg masses to ensure that they hatch successfully. Poor recruitment of young fish will lead to the eventual extinction of colonies. Due to the speed of their decline in range and abundance the spotted handfish became the first marine fish to be listed as endangered under the Federal Environment Protection and Biodiversity Protection Act 1999, and was followed by state protection under Tasmania’s Threatened Species Protection Act 1995.
This image was captured in the Derwent estuary off Nutgrove Beach (2023). The handfish will normally remain still and let you take a few photos. But come mating season they dash about on the seabed floor with lightning speed, making it very difficult to capture an image of them.
