Grazing under experimental hypercapnia and elevated temperature does not affect the radula of a chiton (Mollusca, Polyplacophora, Lepidopleurida)
Sigwart, J.D.; Carey, N. (2014). Grazing under experimental hypercapnia and elevated temperature does not affect the radula of a chiton (Mollusca, Polyplacophora, Lepidopleurida). Mar. Environ. Res. 102: 73-77. https://dx.doi.org/10.1016/j.marenvres.2014.05.004 In: Marine Environmental Research. Applied Science Publishers: Barking. ISSN 0141-1136; e-ISSN 1879-0291, more Also appears in:Kennedy, R.; Allcock, L.; Firth, L.; Power, A.M. (Ed.) (2014). Managing biodiversity in a changing ocean: Proceedings of the 48th European Marine Biology Symposium (EMBS), Galway, Ireland, 19-23 August 2013. European Marine Biology Symposia, 48. Marine Environmental Research, 102(Suppl.). 130 pp., more |  |
| Keywords | Climate Change > Climate Change General
Marine Sciences
Scientific Community
Scientific Publication
Lepidopleurida [WoRMS]
Marine/Coastal | | Author keywords | Lepidopleurida; chiton; Ocean acidification; radula; Biomineralisation; Grazing molluscs |
| Project | Top | Authors | - Association of European marine biological laboratories, more
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| Abstract | Chitons (class Polyplacophora) are benthic grazing molluscs with an eight-part aragonitic shell armature. The radula, a serial tooth ribbon that extends internally more than half the length of the body, is mineralised on the active feeding teeth with iron magnetite apparently as an adaptation to constant grazing on rocky substrates. As the anterior feeding teeth are eroded they are shed and replaced with a new row. The efficient mineralisation and function of the radula could hypothetically be affected by changing oceans in two ways: changes in seawater chemistry (pH and pCO2) may impact the biomineralisation pathway, potentially leading to a weaker or altered density of the feeding teeth; rising temperatures could increase activity levels in these ectothermic animals, and higher feeding rates could increase wear on the feeding teeth beyond the animals' ability to synthesise, mineralise, and replace radular rows. We therefore examined the effects of pH and temperature on growth and integrity in the radula of the chiton Leptochiton asellus. Our experiment implemented three temperature (~10, 15, 20 °C) and two pCO2 treatments (~400 µatm, pH 8.0; ~2000 µatm, pH 7.5) for six treatment groups. Animals (n = 50) were acclimated to the treatment conditions for a period of 4 weeks. This is sufficient time for growth of ca. 7–9 new tooth rows or 20% turnover of the mineralised portion. There was no significant difference in the number of new (non-mineralised) teeth or total tooth row count in any treatment. Examination of the radulae via SEM revealed no differences in microwear or breakage on the feeding cusps correlating to treatment groups. The shell valves also showed no signs of dissolution. As a lineage, chitons have survived repeated shifts in Earth’s climate through geological time, and at least their radulae may be robust to future perturbations. |
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