Feeding innovations and the first coral-feeding fishes
Tubelip wrasses were probably the first modern fish group to feed on corals, an ability that has been linked to their unusual lips. However, the only detailed account of these lips is based on a qualitative description of one tubelip wrasse species. Here, we provide the first quantitative evaluation of the lips of a broad range of wrasses and offer insights into the functional role of lips in coral-feeding fishes. A phylogenetic principal components analysis of 27 morphological traits revealed a clear differentiation between the lips of three coral-feeding tubelip wrasse genera (Labrichthys, Labropsis, and Diproctacanthus) and 12 non-corallivorous genera. This separation among taxa was based primarily on the presence of a glandular lip epithelium in tubelip wrasses. Our findings support the hypothesis that mucus secretion in the lips of tubelip wrasses plays a key role in their coral-feeding ecology, and highlight the value of soft anatomy in enabling fishes to exploit novel trophic resources.
KeywordsCorallivory Fish lips Coral reefs Tubelip wrasses Labridae Functional morphology
We thank S. Reilly, L. Reilly, for support and technical advice; C. Goatley, C. Hemingson, T. Laubenstein, M. Mihalitsis, R. Morais, A. Siqueira, R. Streit, and S. Tebbett, for insightful discussions; and N. Konow and P. Wainwright for helpful comments on the manuscript. This study was funded by the Australian Research Council to D.R.B. (Grant No. CE140100020).
D.R.B. and V.H conceived the study. V.H. processed the samples, collected the data, performed the analyses, and prepared the figures. V.H. and D.R.B. wrote the manuscript.
Compliance with ethical standards
Conflict of interest
On behalf of all authors, the corresponding author states that there is no conflict of interest.
All procedures met the ethics guidelines of James Cook University (Approval No. A2181).
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