Analysis of ontogenetic growth trends in two marine Antarctic bivalves Yoldia eightsi and Laternula elliptica: Implications for sclerochronology
Palaeogeography, Palaeoclimatology, Palaeoecology
Open access. Under a Creative Commons license: https://creativecommons.org/licenses/by-nc-nd/4.0/
There is an increasing use of marine species as palaeoclimate recorders for the marine realm. These archives provide novel baseline records of past oceanographic variability in regions devoid of instrumental observations. Here we report results of a study of the ontogenetic growth pattern of two Antarctic marine bivalve molluscs: Yoldia eightsi and Laternula elliptica from West Antarctic Peninsula populations using negative exponential detrending technique and multi-taper method spectral analysis. Our data show that the growth of both Y. eightsi and L. elliptica follows a general negative exponential trend over their longevity. However, our analyses also identified an innate 9.06 year periodic endogenous growth rhythm in the growth increment pattern of Y. eightsi and two innate periodic growth rhythms, 5 and 6.6 year period, were found in L. elliptica. We hypothesize that the Y. eightsi endogenous growth rhythm may be related to the reallocation of energetic resources between somatic growth and gametogenesis although more biological data are required to test this hypothesis. Further work into L. elliptica biology is required to understand the possible meaning of the innate growth rhythms found for this species. The identification of growth rhythms is important not only for their biological significance but also in sclerochronological analysis because of their importance in developing palaeoenvironmental reconstructions.
We want to give our most sincere thanks to the BAS scuba divers who collected the Y. eightsi specimens. I also want to thank the President's Research Scholarships from Cardiff University for funding this research. We also want to express our gratitude to Prof. Mike Bentley from Durham University, who highlighted the scientific interest of Y. eightsi for climate research. Last but not least we want to thank Dr. Alan Wanamaker Jr. from Iowa State University and an anonymous reviewer who contributed to improve the quality of the paper significantly with their comments and suggestions.
This is the final version of the article. Available from Elsevier via the DOI in this record.
Vol. 465, part B, pp. 300 - 306