Standard Talk (15 mins) Australian Society for Fish Biology Conference 2022

Field-based behaviour of Lorentz’s grunter, Pingalla lorentzi: flee, fight and refuge (#39)

Brendan C Ebner 1 2 , Alastair Freeman 3 , David Bellwood 4 , Sean Doody 5 , Gavin Butler 1
  1. Primary Industries, NSW Fisheries, Grafton, NSW, Australia
  2. TropWATER, James Cook University, Atehrton, QLD, Australia
  3. Aquatic Species Group, Department of Environment and Science, Atherton, Queensland, Australia
  4. College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
  5. Department of Biological Sciences, University of South Florida–St. Petersburg, St Petersburg, Florida, USA

Grunters of the family Terpontidae are important agents in tropical and subtropical freshwater ecosystems of the Australian continent and in a subset of lakes and streams of other Pacific islands. There has been progress in select aspects of grunter science in recent times (i.e. taxonomy; feeding ecomorphology, behaviour, diet; sound communication), but negligible attention given to a wider array of their behaviours and ecology. During surveys (including by baited underwater video) in the Jardine River catchment and adjacent smaller catchments on Cape York Peninsula, observations were made of a little studied endemic species, Lorentz’s grunter. Notable behaviours included fleeing and posturing behaviour in the presence of predators and intraspecific displays and aggression. This research serves to showcase benefits of direct observation in wild fish assemblages in clear water (aquifer-fed) ecosystems. We integrate these observations and our fish assemblage survey data into a conceptual model of the ecology of Lorentz’s grunter focussing on predator-prey and intraspecific-competitive interactions. The conceptualisation captures context of aquatic community composition as mediated by local aquatic habitat features (e.g. low turbidity/high visibility, fringing macrophyte and rock bars). In turn, this conceptualisation becomes usable information for furthering societal understanding and discourse including for potentially protecting the near pristine catchments in Apudthuma country. We also use this process to discuss prospects and challenges for informing the protection and recovery of fishes elsewhere, including recovering species in heavily modified landscapes, such as in the temperate/subtropical Murray-Darling Basin, in the biogeographic range of the critically endangered silver perch, Bidyanus bidyanus.