Epibionts can serve as valuable ecological indicators, providing information about the behaviour or health of the host. The use of epibionts as indicators is, however, often limited by a lack of knowledge about the basic ecology of these ‘hitchhikers’. This study investigated the growth rates of a turtle barnacle, Chelonibia testudinaria, under natural conditions, and then used the resulting growth curve to estimate the barnacle’s age. Repeat morphometric measurements (length and basal area) on 78 barnacles were taken, as host loggerhead turtles (Caretta caretta) laid successive clutches at Mon Repos, Australia, during the 2015/16 nesting season. Barnacles when first encountered ranged in size from 3.7 to 62.9 mm, and were recaptured between 12 and 56 days later. Fitting the growth measurements of these barnacles to a von Bertalanffy growth curve, we estimated the age of these barnacles as a function of their size. Length growth rate decreased over time in a non-linear fashion, while basal area growth rate showed a linear relationship with age. The average estimated age of barnacles at first capture was approximately 6 months (barnacle length 30.3 ± 1.8 mm). The largest and oldest individual had a length of 62.9 mm when first measured, and was estimated to be 642 days old. The finding that C. testudinaria may live for up to 2 years, means that these barnacles may serve as interesting ecological indicators over this period. In turn, this information may be used to better understand the movement and habitat use of their sea turtle hosts, ultimately improving conservation and management of these threatened animals.
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Barnes H (1955) The growth rate of Balanus balanoides. Oikos 6:109–113
Bjorndal KA, Schroeder BA, Foley AM, Witherington BE, Bresette M, Clark D et al (2013) Temporal, spatial, and body size effects on growth rates of loggerhead sea turtles (Caretta caretta) in the northwest Atlantic. Mar Biol 160:2711–2721
Bourget E, Crisp DJ (1975) An analysis of the growth bands and ridges of barnacle shell plates. J Mar Biol Assoc UK 55:439–461
Caine EA (1986) Carapace epibionts of nesting loggerhead sea turtles: Atlantic coast of USA. J Exp Mar Biol Ecol 95:15–26
Cheang CC, Tsang LM, Chu KH, Cheng I-J, Chan BKK (2013) Host-specific phenotypic plasticity of the turtle barnacle Chelonibia testudinaria: a widespread generalist rather than a specialist. PLoS One 8:e57592
Detjen M, Sterling E, Gómez A (2015) Stable isotopes in barnacles as a tool to understand green sea turtle (Chelonia mydas) regional movement patterns. Biogeosciences 12:7081–7086
Eckert KL, Eckert SA (1987) Growth rate and reproductive condition of the barnacle Conchoderma virgatum on gravid leatherback sea turtles in Caribbean waters. J Crust Biol 7:682–690
Ewers-Saucedo C, Arendt MD, Wares JP, Rittschof D (2015) Growth, mortality, and mating group size of an androdioecious barnacle: implications for the evolution of dwarf males. J Crust Biol 35:166–176
Flint M, Patterson-Kane JC, Limpus CJ, Work TM, Blair D, Mills PC (2009) Postmortem diagnostic investigation of disease in free-ranging marine turtle populations: a review of common pathologic findings and protocols. J Vet Diagn Invest 21:733–759
Frick MG, Ross A (2001) Will the real Chelonibia testudinaria please come forward: an appeal. MTN 94:16–17
Frick MG, Williams KL, Robinson M (1998) Epibionts associated with nesting loggerhead sea turtles (Caretta caretta) in Georgia, USA. Herpetol Rev 29:211–214
Frick MG, Williams KL, Veljacic DX, Jackson JA, Knight SE (2000) Epibiont community succession on nesting loggerhead sea turtles, Caretta caretta, from Georgia, USA. Science 64:185–188
Hayashi R, Tsuji K (2008) Spatial distribution of turtle barnacles on the green sea turtle, Chelonia mydas. Ecol Res 23:121
Killingley JS, Lutcavage M (1983) Loggerhead turtle movements reconstructed from 18O and 13C profiles from commensal barnacle shells. Estuar Coast Shelf Sci 16:345–349
Kitsos M-S, Christodoulou M, Arvanitidis C, Mavidis M, Kirmitzoglou I, Koukouras A (2005) Composition of the organismic assemblage associated with Caretta caretta. J Mar Biol Assoc UK 85:257–261
Limpus CJ, Limpus DJ (2003) Loggerhead turtles in the equatorial and southern Pacific Ocean: a species in decline. In: Bolten AB, Witherington BE (eds) Loggerhead sea turtles. Smithsonian Books, Washington DC, pp 199–209
Newman WA, Abbott DP (1980) Cirripedia: the barnacles. Intertidal invertebrates of California. Stanford University Press, Stanford
Pfaller JB, Alfaro-Shigueto J, Balazs GH, Ishihara T, Kopitsky K, Mangel JC, Peckham SH, Bolten AB, Bjorndal KA (2014) Hitchhikers reveal cryptic host behavior: new insights from association between Planes major and sea turtles in the Pacific Ocean. Mar Biol 161:2167–2178
Rasband WS (2015) ImageJ. U. S. National Institutes of Health, Bethesda. www.imagej.nih.gov/ij. Accessed 16 Oct 2015
Robinson NJ, Lazo-Wasem EA, Paladino FV, Zardus JD, Pinou T (2017) Assortative epibiosis of leatherback, olive ridley and green sea turtles in the Eastern Tropical Pacific. J Mar Biol Assoc UK 97:1233–1240
Sloan K, Zardus JD, Jones ML (2014) Substratum fidelity and early growth in Chelonibia testudinaria, a turtle barnacle especially common on debilitated loggerhead (Caretta caretta) sea turtles. Bull Mar Sci 90:581–597
Trager GC, Hwang J-S, Strickler JR (1990) Barnacle suspension-feeding in variable flow. Mar Biol 105:117–127
Vander Zanden HB, Bjorndal KA, Reich KJ, Bolten AB (2010) Individual specialists in a generalist population: results from a long-term stable isotope series. Biol Lett 6:711–714
von Bertalanffy L (1951) Metabolic types and growth types. Am Nat 85:111–117
Zardus JD, Hadfield MG (2004) Larval development and complemental males in Chelonibia testudinaria, a barnacle commensal with sea turtles. J Crust Biol 24:409–421
Zardus JD, Lake DT, Frick MG, Rawson PD (2014) Deconstructing an assemblage of “turtle” barnacles: species assignments and fickle fidelity in Chelonibia. Mar Biol 161:45–49
We thank Duncan Limpus, Lucy Pople, and the Mon Repos rangers and volunteers for field assistance. Sarah Engelhard for assistance in the lab, and Ron West, Chris Henderson and Michael Arthur for assistance with statistical analysis.
Conflict of interest
The authors declared that they have no conflict of interest.
All barnacles were collected from nesting loggerhead turtles following procedures approved by the Griffith University Animal Ethics Committee under permit ENV/06/15/AEC.
Responsible Editor: L. Avens.
Reviewed by: C. Ewers-Saucedo, N. Robinson and J. D. Zardus.
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Doell, S.A., Connolly, R.M., Limpus, C.J. et al. Using growth rates to estimate age of the sea turtle barnacle Chelonibia testudinaria . Mar Biol 164, 222 (2017). https://doi.org/10.1007/s00227-017-3251-5