Table 1.

Experimental Raman data/cm⁻¹ of blue C. sapidus claw cuticle obtained with different laser lines (532, 632.8, 785, 830, 1064 nm) comparatively showed with the theoretical calculated Raman modes of ATX and ncb-ATX.

Raman experimental data/cm−1 of blue C. sapidus cuticle					Calculated Raman modes/cm−1: free ATX, ncb-ATX	Vibrational assignment
532  nm	632.8  nm	785  nm	830  nm	1064  nm
			154	155	—	Calcite (T)
	281	282	284	281	—	Calcite (L)
712	712	712	714	712	—	v4(CO32−) in calcite
—	—	880	—	—	875, 882	ATX δ(CH2)
—	—	—	—	892	—	α-chitin
953sh	953sh	953sh	—	955	923, 929	ATX ν(C-C) + ρ(CH2) + (CH3), α-chitin, v(PO42−)
963	963	963	963	963sh	972sh, 972sh	ATX ν4(C-C) + ρ(CH2) + (CH3), α-chitin, v(PO42−)
1004	1004	1003	1004	1004	992, 997	v3 ATX, ncb-ATX ρ(C-CH3), Phe
—	—	—	—	1038	—	proteins (Phe)
1086	1088	1086	1087	1086	—	v1(CO32−) in calcite
1154	1154	1154	1154	1154	1154, 1154	ATX and ncb-ATX v2(C-C), α-chitin
1190	1190	1197	1190	1190	1186, 1189	ATX, ncb-ATX ν(C-C)
	1205	1203	1206	1202	—	α-chitin
	1234	1234	1234	1234	—	proteins (amide III)
1265	1264	1263	1263	1263	1262, 1269	ncb-ATX, ATX ρ(C-H), α-chitin
1301	1305	1304	1303		1314, 1307	ncb-ATX in crustacyanin
				1325	—	α-chitin
1385	1375	1374	1375	1375	1384, 1384	ATX, α-chitin
				1412	—	α-chitin
1444	1453	1442	—	1448	1444, 1425	ATX, ncb-ATX δasym(CH2,3), α-chitin
1492	1492	1492	1492	1492	absent, 1494	v1(C=C)out-of-plane in
ncb-ATX
1514	—	1514	1514	1514	1508, absent	ATX, v1(C=C)in-plane
		1517		1517sh	absent, 1522	ncb-ATX v1(C=C)in-plane
—	1603	1604	—	—	absent, 1609	ATX, ncb-ATX v(C=C)out-of-plane +
	1621	1619	—	1621	—	Proteins (Trp, Tyr, Phe) + v(C=O),), α-chitin
—	—	1657	—	1655	—	α-chitin, proteins (amide I), α-chitin
—	—	‘—	—	1746	—	Calcite (2v2)
2117	2117	absent	absent	absent	—	v2 + v4 in ATX, ncb-ATX
2158	2158	absent	absent	absent	—	v2 + v3 in ATX,ncb-ATX
2308	2308	absent	absent	absent	—	2v2 in ATX, ncb-ATX
absent	2448	absent	absent	absent	—	v1 + v4 in ncb-ATX
2518	absent	absent	absent	absent	—	v1 + v3 in ATX
absent	2646	absent	absent	absent	—	v1 + v2 in ncb-ATX
2668	absent	absent	absent	absent	—	v1 + v2 in ATX
3028	absent	absent	absent	absent	—	2v1 in ATX
—	—	2877	—	2878	—	α-chitin v(CH2,3)
—	—	2937	—	2934	—	α-chitin v(CH2,3)
—	—	2969	—	2965	—	α-chitin v(CH2,3)

Bands assignment is provided according to our computational chemistry results and literature^{11,12,15,17,24,33}.

Abbreviations: ATX-astaxanthin, ncb-ATX - non-covalently bound astaxanthin, v = stretching, ρ = rocking, δ = bending, T, L -lattice modes in calcite, sh- shoulder.