Ecology

Ecology is the study of the distribution and abundance of organisms. The size of populations and how their numbers fluctuate is affected by environmental and biological factors. Changes in cephalopod population numbers are greatly affected by the environmental conditions that influence the growth and recruitment of young. Most of the information on cephalopod ecology comes from commercial fisheries, with very few objective population surveys done (Boyle and Rodhouse 2005).

The ecology of I. notoides is not well studied, with no published data on population sizes or dynamics. They are endemic to Australian waters and there are known populations of this species in coastal areas close to large human population centres such as Moreton Bay, Queensland (Wollesen et al. 2009) and Fortescue Bay, Tasmania (Tracey et al. 2003), however little is known of the sizes of these or of the trends in their numbers. The IUCN has listed I. notoides as ‘Data Deficient’ on its Red List of Threatened Species because of this general lack of information on its ecology (Barratt and Allcock 2012).

Subjects for this study were collected from the wild population of I. notoides found in Moreton Bay, Queensland. They were found in the seagrass beds, Zostera marina, near Dunwich Harbour on North Stradbroke Island, and are known to use marine vegetation for cover and as an attachment surface on which to lay their eggs. They are nocturnal predators and feed on small crustaceans which they actively hunt (Norman and Reid 2000).