Biogeographic Distribution
The first occurrence of M. pachycera was described by Augener in 1913 in coastal South West Australia (Greg Rouse, unpublished correspondence 2014). Since then, it has been found in many places around the world, including Japan; Southern California; Hawaii; and other regions of Australia, namely Sydney, NSW; and now Brisbane, QLD (Rilov & Crooks, 2009; Australian Museum, 2013; GBIF, 2014). M. pachycera is native to the wider area of Indo-West Pacific (Rilov & Crooks, 2009). To the best of my knowledge, no resolute distribution has been mapped for this species. With such a wide spatial distribution, delineating M. pachycera’s potential range would require a large amount of data, such as water depth, biodiversity and habitat data for the entire Indo-West Pacific marine region. As such, I have not tackled this particular aspect of the species’ biology.
The occurrence of biofouling on objects such as marine vessels has been shown to be the largest contributor to the distribution and consequent introduction of exotic species around the world (Rilov & Crooks, 2009). Due to the brief period of egg incubation and larval development in Autolytines (see Reproductive Behaviour) it seems unlikely that the dispersal in M. pachycera’s pelagic stage is responsible for its global distribution. Instead, the extraordinarily wide distribution of M. pachycera is most likely due to its tendency towards biofouling communities (Rilov & Crooks, 2009). |