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.Cheers Rob McCormack
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.
Benson D. & Baird I. R. C. (2012) Vegetation, fauna and groundwater interrelations in low nutrient temperate montane peat swamps in the upper Blue Mountains, New South Wales. Cunninghamia 12, 267-307. Available from http://www.rbgsyd.nsw.gov.au/science/Scientific_publications/cunninghamia/contents_by_volume/volume_12#twelvefour
Davies, D.A.L. (1998). The genus Petalura: field observations, habits and conservation status (Anisoptera: Petaluridae). Odonatologica, 27, 287-305.
Fleck G. (2011) Phylogenetic placement of Petaluridae and basal Anisoptera families (Insecta: Odonata). Stuttgarter Beiträge zur Naturkunde A Neue Series 4, 83-104.
Hawking J. H. & Theischinger G. (2004) Critical species of Odonata in Australia. International Journal of Odonatology 7, 113-32.
NSW Scientific Committee. (1998) Giant dragonfly – endangered species listing. NSW Scientific Committee final determination. Available from http://www.environment.nsw.gov.au/determinations/GiantDragonflyEndSpListing.htm
NSW Scientific Committee. (2007). Petalura gigantea – endangered species listing amendment. NSW Scientific Committee determination to add Petalura litorea to Part 1 of Schedule 1 (Endangered species) of the Threatened Species Conservation Act. Available from http://www.environment.nsw.gov.au/listings/PetaluraGiganteaAmendment.htm
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
For the past 12 months AABio has been surveying the coastal creeks, streams and swamps of the Coffs Harbour City Council’s local government area. The surveys are now complete and the final report has been issued to Coffs Harbour City Council.
The focus of the survey is freshwater crayfish and crustaceans but all aquatic organisms are surveyed and recorded. We were specifically surveying for Tenuibranchiurus crayfish which are a rare and cryptic species in the area. Typically we would catch 150 C. cuspidatus for only one tenuie. We found abundant Cherax cuspidatus and Euastacus dangadi in the region plus numerous other crustaceans. So far we have found five different species of freshwater shrimp. Most species found are common and expected in the area, however we did make some startling discoveries.
We found some unusual species like limpets but of significance was the discovery of an extremely unusual freshwater crab. We were surveying a coastal creek flowing through a suburban Coffs Harbour area and finding long finned eels (Anguilla reinhardtii), intermediate spiny crayfish (Euastacus dangadi), plague minnows(Gambusia holbrooki), empire Gudgeons (Hypseleotris compressa), riffle shrimps (Australatya striolata), glass shrimp (Paratya australiensis), eastern river prawns, (Macrobrachium tolmerum), toebiters (Stenosialis australiensis), which were all common, abundant and expected. What was not expected was finding a freshwater crab! Not just any ordinary freshwater crab but something quite unusual. It’s a first for the ACP we hadn’t found these before. If in doubt I always contact the expert in that particular field. In this case its Peter Davie from the Queensland Museum, he’s the man for crabs and I asked him, “what this!” He advised it’s a River Swimming Crab, Varuna litterata. A marine crab known to occur in freshwater, being excellent swimmers and able to move with the currents along the coast. In Australia they have only been recorded from south east Queensland and north into Northern Australia (Qld Museum). They are also known to occur in India, East Africa and Japan. The discovery of this species this far south greatly increases the known distribution of the species. A specific research projects to acquire new knowledge on this species has been started with The Australian Crayfish Project www.austcray.com Eventually we will submit a scientific paper on the range extension. For an article with more photos, site locations, water quality data, etc. Go to: River Swimming Crab Article. http://www.austcray.com/2014/08/river-swimming-crab-herring-bow-crab-varuna-litterata-2/
Our thanks to Coffs Harbour City Council and specifically to Rachel Binskin, their Biodiversity Officer for their support of the research project and patience awaiting its completion. The project dragged on longer than expected.
Aquatic Biodiversity Survey and Baseline Mapping of Freshwater Crayfish and Aquatic Species of the Gosford Local Government Area
As Part of the Australian Crayfish Project and a sub project 100056 we have been conducting aquatic biological surveys the whole of the Gosford LGA. This project is major sponsored by Australian Aquatic Biological and receives sponsorship from Gosford City Council under their Ecological Research Grants scheme 2010. The project reached fruition in May 2012 with a total of ten aquatic biological catchments reports being issued to Gosford City Council.
The biological surveys were undertaken as part of both the broad Australian Crayfish Project (ACP) and Australian Aquatic Biological Survey (AABS) and a targeted sub-project on the Gosford LGA, Project 100056, Australian Aquatic Biological 2010.
Surveys of the Gosford LGA are completed on a catchment/drainage basis and a total of ten catchment areas were independently surveyed.
1 Wamberal Lagoon
2 Terrigal Lagoon
3 Avoca Lagoon
4 Cockrone Lagoon and Surrounds
5 Green Point to Kilcare & Bouddi NP – Coastal Streams
6 Erina Creek
7 Narara Creek 100056-7 Completed 67, 77, 78, 86, 87.
8 Point Clare to Mullet Creek
9 Mooney Mooney Creek
10 Mangrove Creek to Wisemans Ferry
This was a two year project that discovered much new information The primary aim of Project No. 100056 is to determine what freshwater crayfish occur where in the Gosford LGA. Primarily freshwater crayfish are the priority and the Gosford LGA represents a significant area for crayfish distributions, yet little is known on the distributions of crayfish in this area. Prior to the start of this research project only two species have recorded distributions within the LGA (Euastacus australasiensis and Euastacus spinifer) yet the extent of their distribution are unknown. Additionally, the area includes a number of coastal lagoons, lakes and streams all with independent catchments draining directly to the Tasman Sea that have been isolated from each other for millions of years and many containing unrecorded crayfish species.
The project also records information on all the other aquatic fauna found in the LGA as well as information on landforms and vegetation. All this is in order to facilitate the better conservation and management of the aquatic ecosystems of the Gosford LGA.
Note: For environmental and hygiene reasons (transfer of pests, diseases and weeds, etc.) each of the catchments are treated as individual systems and are surveyed separately with equipment and personnel being sterilized between catchments. A copy of our Hygiene Protocol and Code of Practice is available online at www.aabio.com.au
We managed to map the distributions of four freshwater crayfish species that occur in the Gosford LGA. Euastacus australasiensis, Euastacus spinifer, Cherax destructor and Gramastacus sp.