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

Table 1 The shells of 13 different mollusc species investigated in this study

Class	Species	Eumelanin	Pheomelanin	Previous reports of eumelanin and methods used
Bivalvia	C. gigas¹	–	–	[30] UV and IR spectroscopy
Bivalvia	L. ornata³	–	–	–
Bivalvia	L. tigrina³	–	–	–
Bivalvia	M. yessoensis³	–	–	[33] UV spectrophotometry and HPLC–UV
Bivalvia	M. edulis²	+	–	–
Bivalvia	P. maximus³	–	–	–
Cephalopoda	N. pompilius⁴	+	–	–
Gastropoda	C. nemoralis⁵	+	+	[7, 20] solubility tests
Gastropoda	C. pharaonius⁶	~ + ^*	–	[21] HPLC–UV
Gastropoda	C. marmoreus³	–	–	–
Gastropoda	C. tigris³	–	–	–
Gastropoda	H. asinina⁷	–	–	–
Gastropoda	S. adriatica⁸	+	–	–

A “+” signifies the presence of oxidation products of eumelanin or pheomelanin in our HPLC–MS analyses, a “- “signifies we could not detect any melanin oxidation products. ¹purchased from food market (Vienna, March 2018), ²purchased from grocery store (Göttingen, March 2018), ³purchased from Conchology Inc. (www.conchology.be), ⁴Donation from M. Hundertmark private collection, ⁵collected at botanical gardens of Georg-August University of Göttingen (September 2017), ⁶Donation from Natural History Museum Vienna (1 sample) and purchased from Schnecken und Muscheln (www.schnecken-und-muscheln.de) (2 samples), ⁷Donation from D. J. Jackson private collection, ⁸collected from Jackson group aquarium (December 2017–March 2018). ^*Eumelanin was detected in one out of three samples

ISSN: 1742-9994