Based on the results of the Australian Crayfish Project a scientific paper on the translocation of the yabby Cherax destructor into eastern drainages of New South Wales, has been published in the scientific journal “Australian Zoologist”. The Royal Zoological Society publishes a fully refereed scientific journal, Australian Zoologist, specialising in topics relevant to Australian zoology. The Australian Zoologist was first published by the Society in 1914, making it the oldest Australian journal specialising in zoological topics. The scope of the journal has increased substantially in the last 20 years, and it now attracts papers on a wide variety of zoological, ecological and environmentally related topics.The Royal Zoological Society of New South Wales is a non-profit, scientific organisation dedicated to the study and conservation of native Australian fauna. http://rzsnsw.org.au/
The blue claw yabby Cherax destructor is a native of the Murray Darling drainage basin in the interior of south-eastern Australia. In New South Wales (NSW) the species naturally occurs west of the Great Dividing Range but recently, it has become established in eastern parts of NSW, outside of its natural range. The potential threats and translocation of this species into eastern NSW was first documented at 20 sites by Coughran et al. (2009). This paper builds on their initial work and documents a further 52 translocation sites (Table 1) recorded over the last four years. In an effort to further our understanding of the threat, we present information on the dispersal of this species together with observational information on interactions with freshwater crayfish (Parastacidae) species and suggest recommendations to help slow the translocation process.
McCormack, R.B. (2014). New records and review of the translocation of the yabby Cherax destructor into eastern drainages of New South Wales, Australia. Australian Zoologist. Volume 37 (1) 85 – 94. ISSN 0067-2238 (Print). http://doi.org/10.7882/AZ.2014.006
Yabbies make great pets and are excellent eating, but unlike the endemic freshwater crayfish in eastern drainages, they grows fast, mature early, breed frequently and have a shorter gestation period. These are traits that equip it to potentially out-compete the endemic freshwater crayfish. Their rapid proliferation, aggressive disposition and invasive habits tend to rapidly displace the endemic eastern crayfish. The NSW Fisheries Scientific Committee has listed ‘The introduction of fish to fresh waters within a river catchment outside their natural range’ as a Key Threatening Process (KTP) under the Fisheries Management Act 1994 (FM Act), and the yabby is certainly a threat in eastern NSW. This paper documents ACP research over the last 4 years and is a must for those interested in the conservation of our endemic eastern crayfish species.
In late December 2014, I met up with Dr Ian Baird one of Australia’s foremost experts on Giant Dragonflies and we spent the day together wandering selected swamps of the Blue Mountains hunting this rare and elusive species. This was an eye opener for me and I had a fantastic day learning all about Giant Dragonflies. The following information on the species was provided by Ian.
Petalura gigantea, commonly known as the Giant Dragonfly or Southeastern Petaltail is a very large dragonfly which may have a wingspan up to 13 cm. It is recorded from selected peat swamps, bogs and seepages (mires) along the coast and ranges of NSW from Nadgee Nature Reserve near the Victorian border, to near the Qld border in and around Basket Swamp National Park and Boonoo Boonoo State Forest. It has also been observed in nearby Girraween National Park in southeastern Qld.
It has been recorded in swamp habitats from near sea level to 1240 m elevation. Listed as endangered in NSW under the NSW Threatened Species Conservation Act 1995, with habitat loss and degradation identified as the main threats to the species.
In addition to the large size and widely separated dark eyes, the species (and genus) is characterised by a long pterostigma (darkened cell) towards the distal end of the leading edge of the wings, and large petaloid superior anal appendages in adult males. Adult females lack the conspicuous petaloid appendages and are somewhat bulkier than males.
The family is unique amongst dragonflies, in that larvae excavate burrows which extend below the water table in soft peaty soils in mires, seepages or along stream margins. The larvae (mudeyes) occupy and maintain these burrows for their entire larval period, generally surviving on creatures captured within the burrow system, or perhaps ambushed at the burrow entrance. Larvae may leave their burrows to hunt under favorable conditions, but this behaviour has not been confirmed. Petalurid dragonflies have very long larval stages, which are known to extend for at least five years in two overseas species. Extrapolation from recent studies by Ian and Dr John Trueman, suggest, respectively, a larval stage of at least six years, and possibly 10 or more, in P. gigantea. Ian was extremely skilled at locating burrows and he found 10:1 to what I did. I was desperately searching for an occupied burrow but only ever found those recently vacated.
After this extended larval stage they emerge (October-January) and climb the nearest shrub or sedgeland vegetation to undergo emergence, usually leaving their larval skin (exuvia) attached to their shrub or sedge emergence supports. Ian and I surveyed the Katoomba swamp and I was astounded at the number of exuvia we found amongst the sedges. Ian indicated that this was an unusually large emergence event for this swamp patch.
Adults live for a maximum of one summer flying season, which extends into February at least, with occasional late flying individuals having been observed on one occasion as late as mid-March in the Blue Mountains.
My thanks to Ian for a most enjoyable and informative day. I’ll certainly be keeping an eye out for Giant Dragonflies in the future.
Selected references for Petalura gigantea
Baird I. R. C. (2012) The wetland habitats, biogeography and population dynamics of Petalura gigantea (Odonata: Petaluridae) in the Blue Mountains of New South Wales. PhD thesis, University of Western Sydney, Australia. Available from http://handle.uws.edu.au:8081/1959.7/509925.
Baird I. R. C. (2013) Emergence behaviour in Petalura gigantea (Odonata: Petaluridae): confirmation of upright emergence. International Journal of Odonatology 16, 213-8. doi:10.1080/13887890.2013.798975
Baird, I.R.C. (2013). Larval habitat and behaviour of Phenes raptor (Odonata: Petaluridae): a review of current knowledge, with new observations. International Journal of Odonatology, 16, 79-91. doi:10.1080/13887890.2012.757723
Baird, I.R.C. (2014). Larval burrow morphology and groundwater dependence in a mire-dwelling dragonfly, Petalura gigantea (Odonata: Petaluridae). International Journal of Odonatology, 17, 101-121. doi:10.1080/13887890.2014.932312
Baird, I.R.C. (2014). Mate guarding and other aspects of reproductive behaviour in Petalura gigantea (Odonata: Petaluridae). International Journal of Odonatology, 17, 223-236. doi:10.1080/13887890.2014.979333
Baird I. R. C. & Burgin S. (2013) An emergence study of Petalura gigantea (Odonata: Petaluridae). International Journal of Odonatology 16, 193-211. doi:10.1080/13887890.2013.798580
Baird I. R. C. & Ireland C. (2006) Upright emergence in Petalura gigantea (Odonata: Petaluridae). International Journal of Odonatology 9, 45-50.
Theischinger G. (1975) Ein “Dreigespann” von Petalura gigantea Leach. Tombo 18, 45. (In German, with English summary).
Theischinger G. (1999) A new species of Petalura Leach from south-eastern Queensland (Odonata: Petaluridae). Linzer biologische Beiträge 31, 159-66.
Theischinger G. & Endersby I. (2009) Identification Guide to the Australian Odonata. Department of Environment, Climate Change and Water NSW, Hurstville, NSW.
Theischinger G. & Hawking J. H. (2006) The Complete Field Guide to Dragonflies of Australia. CSIRO, Collingwood, Vic.
Tillyard, R.J. (1909). Studies in the life-histories of Australian Odonata. 1. The life-history of Petalura gigantea Leach. Proceedings of the Linnean Society of NSW, 34, 256-267.
Tillyard, R.J. (1911). Studies in the life-histories of Australian Odonata. 4. Further notes on the life-history of Petalura gigantea Leach. Proceedings of the Linnean Society of NSW, 36, 86-96.
Ware, J.L., Beatty, C.D., Sanchez Herrera, M., Valley, S., Johnson, J., Kerst, C., May, M.L. & Theischinger, G. (2014). The petaltail dragonflies (Odonata: Petaluridae): Mesozoic habitat specialists that survive to the modern day. Journal of Biogeography, 41, 1291-1300. doi:10.1111/jbi.12273