Thymichthys politusRed Handfish
Despite being red, this species can be very difficult to find amongst the base of seaweeds. Females lay eggs at the base of seagrass or green Caulerpa seaweeds in spring and stand guard until they hatch. Arguably one of the rarest marine fish species in the world. Found at Port Arthur in the 1800's and once spread across south-eastern Tasmania, it is now only known from two small patches of rocky reef in south-eastern Tasmania, with the number of adults believed to be less than 100-150. RLS monitoring data were critical in the evaluation of this species for the IUCN red list and categorisation as Critically Endangered.
*note the occurrence information below reflects its occurrence at the one site monitored by RLS divers within its known distribution.
Max Size: 10 cm
Sea Temperature Range: 9.6-18.5°C
Depth: 2 - 7 m
Habitat Generalization Index: N/A
Also referred to as the SGI (Species Generalisation Index), this describes the habitat niche breadth of the species. Species with values less than 15 are found in a relatively narrow range of reef habitat types (specialists), while those over 25 may be found on most hard substrates within their range (generalists). Learn more here.
Conservation and Rarity
IUCN Status: Critically Endangered
Occurrence: Widespread (100% of sites)
Occurrence describes how often the species is found on surveys within its distribution. It is calculated as the % of reef sites surveyed by RLS divers across all the ecoregions in which the species has been observed
Abundance: Few (2 per transect)
Abundance is calculated as the average number of individuals recorded per RLS transect, where present.
Edit by: Rick S-S