The smooth handfish (Sympterichthys unipennis) is a benthic fish endemic to south-east Tasmania that is now presumed to be extinct. It belongs to the same family as four extant, threatened handfish species that are also endemic to the south-east of the state, have restricted ranges and have all experienced population declines. The smooth handfish was listed as extinct on the IUCN Red List in 2020.
This benthic species is known only from the holotype specimen collected more than 200 years ago in shallow waters of south-east Tasmania during the first scientific exploration of southern Australia. It was amongst the first Australian fish species collected and was almost certainly a common species at the time of discovery.
There have been no records of this species over the past 200 years and extensive surveys targeting handfish species in the shallow habitats that it occupied have not recorded any individuals. Many factors may have contributed to its demise, but commercial scallop dredging conducted in its habitat during the 20th century is likely to have had a significant impact.
