Abstract
Linear regression between CPD and environmental UV-B dose in the intertidal sea anemone Actinia tenebrosa (A; filled circles) and the gastropod Diloma aethiops (B; open circles) from the Otago Harbour (New Zealand, S 45° 47′52.4″; E 170° 42′54.0″). Scale bars represent 10mm. [Display omitted]
•MAA concentrations, DNA damage and UV-B irradiances were compared in an intertidal sea anemone (Actinia tenebrosa) and gastropod (Diloma aethiops).•Maximum MAA concentrations and environmental UV-B irradiances were not positively correlated.•Instead, a six months lag-time in total MAA concentration was observed in A. tenebrosa, a situation that consequently did not provide efficient UV-protection during summer months.•MAA levels in D. aethiops did not change during temporal UV-B variation.•In addition to MAA, physical adaptations, such as an opaque shell, may be important to reduced DNA damage in the gastropod D. aethiops.
The photoprotective role of mycosporine-like amino acids (MAA) against the generation of DNA cyclobutane pyrimidine dimers (CPD) was studied in the sessile intertidal anemone Actinia tenebrosa and the mobile intertidal gastropod Diloma aethiops through 27months at a mid-latitude New Zealand location. MAA were sequestered by A. tenebrosa and D. aethiops from their diet, although maximum total MAA levels in both species were not correlated with seasonal variation in maximum ambient UV-B levels recorded at the collection site. Temporal changes in total MAA in A. tenebrosa showed a six months lag-time in their concentration regarding to the environmental UV-B levels. This lag period corresponded to an observed increase in CPD production from spring to summer; suggesting that MAA do not completely protect the anemone from UV-B during summer. For D. aethiops, total MAA concentrations did not change significantly during the study, although qualitative changes in MAA were apparent. A month lag-time in MAA concentration in D. aethiops and possibly the physical barrier that the shell confers to the animal, can explain reduced CPD levels in comparative terms with A. tenebrosa. Although MAA are used by invertebrates for photoprotection, contrasting mobility characteristics and the presence of physical adaptations can confer them important protection levels during temporal changes of UV-B at mid-latitude places of the Southern Hemisphere.