title: Functional diversity of the lateral line system among populations of a native Australian freshwater fish.
abstract: Fishes use their mechanoreceptive lateral line system to sense nearby objects by detecting slight fluctuations in hydrodynamic motion within their immediate environment. Species of fish from different habitats often display specialisations of the lateral line system, in particular the distribution and abundance of neuromasts, but the lateral line can also exhibit considerable diversity within a species. Here, we provide the first investigation of the lateral line system of the Australian western rainbowfish (Melanotaenia australis), a species that occupies a diversity of freshwater habitats across semi-arid northwest Australia. We collected 155 individuals from eight populations and surveyed each habitat for environmental factors that may contribute to lateral line specialisation, including water flow, predation risk, habitat structure and prey availability. Scanning electron microscopy and fluorescent dye labelling were used to describe the lateral line system inM. australis, and to examine whether the abundance and arrangement of superficial neuromasts (SNs) varied within and among populations. We found that the SNs ofM. australiswere present in distinct body regions rather than lines. The abundance of SNs within each body region was highly variable, and also differed among populations and individuals. Variation in SN abundance among populations was best explained by habitat structure and the availability of invertebrate prey. Our finding that specific environmental factors explain among-population variation in a key sensory system suggests that the ability to acquire sensory information is specialised for the particular behavioural needs of the animal.
authors.affiliation: School of Biological Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia.
authors.forename: Lindsey
authors.initials: L
authors.lastname: Spiller
authors.affiliation: School of Biological Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia.
authors.forename: Pauline F
authors.initials: PF
authors.lastname: Grierson
authors.affiliation: Centre of Excellence in Natural Resource Management, The University of Western Australia, Albany, Western Australia 6332, Australia.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Davies
authors.affiliation: School of Biological Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia.|UWA Oceans Institute, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia.
authors.forename: Jan
authors.initials: J
authors.lastname: Hemmi
authors.affiliation: School of Biological Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia.|UWA Oceans Institute, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia.
authors.forename: Shaun P
authors.initials: SP
authors.lastname: Collin
authors.affiliation: School of Biological Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia Jennifer.kelley@uwa.edu.au.
authors.forename: Jennifer L
authors.identifier: 0000-0002-8223-7241
authors.initials: JL
authors.lastname: Kelley
mesh_terms: D000818:Animals; D001315:Australia; D005260:Female; D005399:Fishes / Q000033:anatomy & histology*; D053403:Lateral Line System / Q000033:anatomy & histology* / Q000648:ultrastructure; D008297:Male; D033401:Microscopy, Acoustic; D008856:Microscopy, Fluorescence; D014872:Water Movements; D014904:Western Australia
keywords: Adaptation; Altered flow regimes; Population variation; Sensory evolution