Eumelanin and pheomelanin pigmentation in mollusc shells may be less common than expected: insights from mass spectrometry ...

• Main Authors: Affenzeller, Susanne, Wolkenstein, Klaus, Frauendorf, Holm, Jackson, Daniel
• Format: Dataset
• Language: English
• Published: Dryad 2020
• Subjects: Eumelanin; pheomelanin; Shell Pigment; Liquid chromatography–mass spectrometry; colour pattern; Nautilus; Crassostrea gigas
• Online Access: https://dx.doi.org/10.5061/dryad.h70rxwddx; https://datadryad.org/stash/dataset/doi:10.5061/dryad.h70rxwddx

Background: The geometric patterns that adorn the shells of many phylogenetically disparate molluscan species are comprised of pigments that span the visible spectrum. Although early chemical studies implicated melanin as a commonly employed pigment, surprisingly little evidence generated with more recent and sensitive techniques exists to support these observations. Results: Here we present the first mass spectrometric investigations for the presence of eumelanin and pheomelanin in 13 different molluscan species from three conchiferan classes: Bivalvia, Cephalopoda and Gastropoda. In the bivalve Mytilus edulis we demonstrate that eumelanin mainly occurs in the outermost, non-mineralised and highly pigmented layer of the shell (often referred to as the periostracum). We also identified eumelanin in the shells of the cephalopod Nautilus pompilius and the marine gastropods Clanculus pharaonius and Steromphala adriatica. In the terrestrial gastropod Cepaea nemoralis we verify the presence of pheomelanin in a ... : Samples and standards Shells from 13 different mollusc species were obtained either commercially or by donation from the Natural History Museum Vienna or private collectors for ana- lysis (see Fig. 1 for images of samples used and Table 1 for previous literature and sample sources). For species previously reported to contain eumelanin in their shells (Crassostrea gigas, Mizuhopecten yessoensis, Clanculus pharaonius [21, 30, 33]) three replicates were analysed. For Mizuhopecten yessoensis the brown coloured left valve and for Cepaea nemoralis a morph with yellow background and multiple brown bands was analysed. For Mytilus edulis the periostracum was removed by scrub- bing the shell with sand for one shell valve, while the other valve remained intact. As Steromphala adriatica are very small, seven shells were combined into one sample. Samples contained 0.9 to 2.2 g of shell material each. For Lioconcha ornata 0.5g of shell material was available. Note that shells displaying multiple colours were not ...