Dr Jeffrey M Leis, Australian Museum, Sydney and IMAS
Ulrike Siebeck, University of Queensland, St Lucia
Danielle L Dixson, James Cook University, Townsville
Time and date: 1-2 pm, Wednesday the 12th of October
Venue: Seminar room, IMAS Taroona
Abstract:
Teleost reef fishes have a bipartite life history: a demersal adult phase with limited mobility and a dispersive, pelagic larval phase that lives in open water for several weeks to months before settling onto a reef. Larval dispersal is a biophysical process, so, behaviour of fish larvae influences dispersal outcomes, thus setting the scale of population connectivity. Orientation by small pelagic animals in a moving water column is challenging, and the sensory cues and systems used by larvae for orientation are poorly understood. The little existing research has focused on sound, smell and sight, but has revolutionized our view of the capabilities of these small fishes (5-30 mm). Larval fishes can hear reefs from several km and localize underwater sound sources, yet the physiological mechanisms used are unclear. Larvae can distinguish different reefs by scent, locate settlement habitat by scent, and avoid predator scents, but the scale over which can be done is unclear. Direct use of vision for orientation is limited by water clarity to a few 10s of m, but larval-fish visual orientation over very large scales using celestial cues or polarized light is implied by a few studies. Use of other cues by larval reef fishes, such as wave direction or magnetic fields has been hypothesized, but not studied. Several orientation cues operating over different spatial scales are likely used. An integrated approach combining laboratory work on electro-physiology & functional morphology and field work on sensory ecology are required to understand larval-fish orientation. Such understanding is essential to model and measure dispersal and population connectivity, and to manage living marine resources and marine protected areas.
Biography:
Jeff Leis is a Senior Principal Research Scientist in Ichthyology at the Australian Museum in Sydney. He has been fascinated by and studied Indo-Pacific fish larvae for 40 years. Jeff did his BSc in Zoology at the University of Arizona, where he got his ichthyological start in the Gulf of California, and his PhD in Biological Oceanography at the University of Hawaii, where he fell in love with coral reefs and their fishes. After 18 months in southern California, studying the impact of nuclear power stations on fish larvae, he departed the USA for a 2-year fellowship in Australia, and became a new Australian. Jeff’s research on fish larvae has provided a taxonomic base for their study in the Indo-Pacific, used them to reveal the relationships of fishes, and shown their behaviour can strongly influence dispersal in the ocean. He has been privileged to participate in the Australian Museum’s golden age, to collaborate with a wide variety of stimulating people, and to do field work in the most interesting places. Jeff’s research has helped to shine some light into the black box of larval-fish biology, and he has enjoyed every minute of it.