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Wrasse; Snakeskin

Wrasse; Snakeskin

Eupetrichthys angustipes

There are over 400 species worldwide within the wrasse family, Labridae, roughly half of which are found in Australia.  Size, shape and behavioural patterns vary greatly between species, however one common characteristic of this family is that they are protogynous hermaphrodites.  That is all juveniles are born female, they consequently join a female harem that is dominated by a single male and if the behavioural cues of the male are missing the largest female will ultimately change sex.  The snakeskin wrasse has an elongate body that is a variable grey to brown mottled colouration with a dark band horizontally along the upper half of the body and several broad bands vertically down the sides, with numerous spots over the head.  Juveniles are dusky along the upper half and pale along the ventral surface of the body, with broad banding.  The males differs by being greenish-grey on the dorsal surface, and the banding on the body is more distinct.  The snakeskin wrasse grows to a maximum length of 20 centimetres.

The snakeskin wrasse is endemic to southern Australian temperate waters, occurring from the Houtman Abrolhos Islands to the Solitary Islands, NSW and around Tasmania.  This species inhabit shallow coastal bays in vegetated areas with seaweed,  Posidonia and Amphibolis seagrass species present, to deep offshore to depths of 40 metres.  They also inhabit sponge gardens and rocky reefs and consume a variety of benthic invertebrates.  They have an unusual mode of swimming by having a head-up posture above the seafloor, rising in short bursts up from the bottom.  When resting, the snakeskin wrasse lies on its side with the head turned up at an angle, appearing sick or injured.

 

Occurrence at the Busselton Jetty: 

At first glance the snakeskin wrasse is somewhat similar in appearance and behavior to Castlenau’s wrasse, both species also occupy the same habitat.  However, they can be distinguished by the spotting over the head and the horizontal white band down the length of the body.  If observed for a period of time they also have a unique swimming method.  The snakeskin wrasse is commonly observed from the underwater observatory, generally through the seagrass window.