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Archive for May, 2015

Day active jack jumper, Myrmecia croslandi has three spectral classes of photoreceptors.

Day-active jack jumper, Myrmecia croslandi has three spectrally distinct types of photoreceptors

Bees and wasps are known to be trichromats (three classes of photoreceptors). Ants were thought to be the only hymenopterans to be dichromats, being sensitive to UV and green wavelength of the spectrum. Several behavioural experiments have suggested that ants do use colour vision, but it has been unclear whether ants are dichromats, trichromats or tetrachromats. Teaming up with electrophysiology experts Yuri Ogawa, Jan Hemmi, Marcin Falkowski at UWA and visual ecologist Jochen Zeil at ANU we show from intracellular and extracellular recordings that ant photoreceptors have three spectral sensitivities, sensitive to UV, blue and green wavelength – that allows for trichromacy. Interestingly, this holds good for ants active during both day and night. We argue that colour vision may have evolved in the context of landmark guidance, since the evolution of trichromacy in insects predates the evolution of flowers.

See: Ogawa Y, Falkowski M, Narendra A, Zeil J, Hemmi JM. 2015. Three spectrally distinct photoreceptors in diurnal and nocturnal Australian ants. Proceedings of the Royal Society B 282: 20150673.

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We are seeking expressions of interest for two postdoctoral positions to examine the neurobiology of insect navigation. Both positions are for three years and will be based at Macquarie University, Sydney.

A section through the brain of a nocturnal Queen Bull ant, Myrmecia pyriformis. Ca: calyx, Pe: peduncle, Cb: central body; Lo: lobula, Me: medulla, La: lamina; Al: antennal lobe

Cross section of the brain of a Bull ant queen, Myrmecia pyriformis. Ca: calyx, Pe: peduncle, Cb: central body; Lo: lobula, Me: medulla, La: lamina; Al: antennal lobe

1. Postdoctoral Research Associate (Macquarie University salary Level A6, three-year position): The role will involve development of a research program in electrophysiology and neuropharmacology of ants to determine the brain regions involved in navigation. It will require skills in intracellular recording, and/or calcium imaging, brain morphometrics, extracellular recording, and the creative capacity to develop electrophysiological and neuropharmacological methods in a new system. The position would allow for associate supervision of graduate students.

2. Postdoctoral Research Assistant (Macquarie University salary Level H6 step 1, three-year position at 0.8 full time equivalent): The role would involve conducting experiments in ant behavioural pharmacology in both the laboratory and the field. It will require skills in field research, quantitative analysis of animal behaviour, neuropharmacology, insect brain histology and 3D reconstruction. The position would be funded at 80% of full-time equivalence (four days a week), with an additional opportunity to take up undergraduate teaching duties to supplement the salary. The position would allow for associate supervision of graduate students.

If this sounds intriguing, fun and fascinating, contact me: ajay.narendra [at] mq.edu.au. More details on these positions are available on our lab page.

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