To examine selection of habitat by juvenile M. latisulcatus, a eries of 33 tanks was set-up in controlled environment rooms.
Each round tank was 58 cm in diameter, 43-cm deep, and filled to a depth of 35 cm.
Fresh seawater was continuously supplied to each tank.
Two different habitats were established in each tank, combinations randomly re-assigned to tanks after each trial.
Room temperature was maintained at 20°C, but water temperature varied naturally from 19°C in April to 13°C in June when the experiment finished.
Juvenile prawns were collected at night using a beam trawl in the northern portions of Gulf St.
Vincent and Spencer Gulf, and held in 500-1 outdoor holding tanks with flow through seawater until needed.
Three size classe of prawn were used to determine if the preferred habitat changed with size.
A random sample of 50 prawns from each size class were measured for carapace length, with small prawns having a mean length of 4.6 mm (range 3.1-5.9), medium 7.6 mm (6.2-9) and large 12.8 mm (0.4-17.2).
The influence of predators on selection of habitat by medium-sized prawns was tested by placing a single mullet or blue crab into the appropriate tanks.
Both species have previously been identified as predators of penaeid prawns predators.
All predators were starved for 24 h prior to use to encourage active foraging during the experiment.
To determine if the habitat selected varied with time of day, both day and night trials were run.
We carried out five replicate trials for each combination of factors ested.