Roe’s Abalone
Scientific name: Halliotis roei
Phylum: Mollusca
Distribution:
Roe’s abalone are found around the western and southern Australian coast from Shark Bay to Victoria.
Description:
Roe’s abalone are gastropod molluscs that can grow up to 12.5 centimetres across the shell. They are almost half the sizes of greenlip and brownlip abalone, which are the other two commercially and recreationally important abalone species in Western Australia.
The shell of Roe’s abalone is sculptured and darkly pigmented and is readily distinguished from the smooth shell of the greenlip abalone and the conical shell of brownlip abalone.
Ecology:
They are found mostly on the shallow limestone coastal reefs along the west coast. They prefer rough water where there is intense wave action, in depths of 10 centimetres to 4 metres.
They may live for 10 or more years, but are difficult to age because size depends on the abundance of food as well as their age.
Adult abalone feed at night, using a rasping tongue (radula) to graze algae from a small area around them. However, raising its shell to clamp down on algae floating in the water catches most of their food. They are selective feeders, preferring red algae.
Roe’s abalone spawn mostly in winter and female abalone can release up to two millions eggs. They are fertilised externally and within 48 hours they have developed into tiny larvae. The larvae drift with the currents for about a week before they transform into small abalone and settle on the ocean bottom.
The small abalones settle in holes and crevices in the reef and graze on pink coralline algae. After they grow too big for the small crevices where they first settled, they will move to deeper sections of the reef.
Abalone may fall prey to stingrays, fish, octopuses, rock lobsters, seastars, predatory whelks or man.
Interesting facts:
Roe’s abalone is named after John Septimus Roe, a surveyor on board the ship The Mermaid which charted the coastline and animal species of the WA’s coast. Roe became Surveyor General of the Swan River colony and recommended the sites of where Perth and Fremantle now exists.
Roe's abalone can live in extremely high population densities of up to 400 animals per square metre.
Status:
In recent years, Roe's abalone has come under pressure from both an increasing human population and its growing popularity as a delicacy. The proximity of Perth (Western Australia's capital and most densely populated city) to reefs along the beaches makes the Roe's abalone fishery vulnerable. The commercial and recreational fishery operates under strict management arrangements.
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