The Bay Prawn Scientific name Metapenaeus bennettae
The Bay Prawn is also known as the Greasyback Prawn or the Greentail Prawn. It is found along the East Coast of Australia from Rockhampton in Queensland to the Gippsland Lakes in Victoria. It is the smallest and most numerous of the commercial species of prawns targeted by the Moreton Bay Trawler Fishery. It is the only species of commercial prawn which can spend its entire life cycle in shallow estuarine waters. They can be found in rivers and out in Moreton Bay and can handle a wide range of salinities. As the prawns develop they can be located further out from the rivers and creeks associated with Moreton Bay. Generally the close in river trawlers catch sub-adults which are used for the bait market, whereas the larger prawns are caught out in the bay along with other species of prawns and are kept for human consumption.
Bay Prawns are basically bottom feeders preferring the fine silt and mud although they can also cope with sandy substrates. Juveniles are often associated with shallow mangrove lined estuaries and waterways. They take around a year to reach maturity when the males reach a length of 8 cm and females around 10 cm. When fully grown a female can be up to 13 cm in length, quite a bit smaller than other commercial species of prawn.
Identifying juvenile species of prawns can be almost as difficult as some of the juvenile fish that frequent areas like Bremner Road Saltmarsh. In South east Queensland many of the estuary and mangrove habitats are utilised by school, bay and banana prawns during the summer months. They can be difficult to tell apart as they have similar colouration when they are juveniles although the bay prawns tend to have some pronounced spotting in their colouration and a rough shell (which distinguishes them from the school prawn). Identifying juvenile prawns is tricky as volunteers carrying out monitoring work have to work quickly in order to return the fish and prawns to the water in a healthy state.