*4.1. General*

The UV-visible (UV-VIS) spectra were recorded with a Hitachi U-2001 (Hitachi High-Technologies Corporation, Tokyo, Japan) in diethyl ether (Et2O). The positive ion electro spray ionization time of flight mass (ESI-TOF MS) spectra were recorded using a Waters Xevo G2S Q TOF mass spectrometer (Waters Corporation, Milford, CT, USA). The 1H-NMR (500 MHz) spectra were measured with a Varian UNITY INOVA 500 spectrometer (Agilent Technologies, Santa Clara, CA, USA) in CDCl3 with TMS as an internal standard. HPLC was performed on a Shimadzu LC-6AD with a Shimadzu SPD-6AV spectrophotometer (Shimadzu Corporation, Kyoto, Japan) set at 470 nm. The column used was a 250 × 10 mm i.d., 10 ΐm Cosmosil 5C18- II (Nacalai Tesque, Kyoto, Japan) with acetone:hexane (3:7, v/v) at a flow rate of 1.0 mL/min, run time of 60 min. The optical purity of astaxanthin was analyzed by chiral HPLC using a 300 × 8 mm i.d., 5 ΐm Sumichiral OA-2000 (Sumitomo Chemicals, Osaka, Japan) with *n*-hexane/CHCl3/ethanol (48:16:0.8, v/v) at a flow rate of 1.0 mL/min [23]. 

## *4.2. Animal Specimens*

The sea angel *C. limacina* (30 specimens, 464 mg wet weight) was collected at Monbetsu bay, Monbetsu City, Hokkaido, Japan in December 2011. Another sea angel, *P. doliiformis* (60 specimens, 1041 mg wet weight), was also collected at Monbetsu bay in April 2013. The small sea snail 

*L. helicina* (6 specimens, 200 mg wet weight) was collected at Monbetsu bay in May 2013. Chum salmon, *O. keta* (3 specimens, five to six years of age), was collected at Monbetsu in September 2013. 

## *4.3. Analysis of Carotenoids*

The extraction and identification of carotenoids were carried out according to our routine methods [24]. Carotenoids were extracted from living or fresh animal specimens with acetone. The acetone extract was translated to an ether-hexane (1:1) layer by the addition of water. The total carotenoid contents were calculated employing an extinction coefficient of E1%cm = 2100 [25] at Ώ max. The ether-hexane solution was evaporated. The residue was subjected to HPLC on silica gel. Carotenoid compositions were estimated by the peak area of the HPLC on silica gel with acetone–hexane (2:8)–(4:6) monitored at 450 nm. 

Individual carotenoids were identified by retention time in HPLC, UV-vis (ether), ESI-TOF MS, and 1H NMR (500 MHz, CDCl3) in the case of pecetenolone. 

*4.4. Identification of Carotenoids* 

Ά-Carotene (**1**). ESI-TOF MS: *m/z* 536.4372 [M]+ (calcd for C40H56, 536.4382); UV-VIS: 425, 449, 475 nm. 

Echinenone (**2**). ESI-TOF MS: *m/z* 551.4271 [M + H]+ (calcd for C40H53O, 551.4253); UV-VIS: 460 nm. 

Canthaxanthin (**3**). ESI-TOF MS: *m/z* 565.4044 [M + H]+ (calcd for C40H53O2, 565.4046); UV-VIS 470 nm. 

Ά-Cryptoxanthin (**4**). ESI-TOF MS: *m/z* 553.4511 [M + H]+ (calcd for C40H53O, 553.4409); UV-VIS: (425), 450, 475 nm. 

Zeaxanthin (**5**). ESI-TOF MS: *m/z* 569.4353 [M + H]+ (calcd for C40H57O2,569.4359); UV-VIS: (425) 450, 475 nm. 

Adonixanthin (**6**). ESI-TOF MS: *m/z* 583.4139 [M + H]+ (calcd for C40H55O3, 583.4151); UV-VIS 460 nm. 

Idoxanthin (**7**). ESI-TOF MS: *m/z* 599.4090 [M + H]+ (calcd for C40H55O4, 599.4100); UV-VIS 460 nm. 

Astaxanthin (**8**). ESI-TOF MS: *m/z* 597.3942 [M + H]+ (calcd for C40H53O4, 597.3944); UV-VIS 472 nm, Chiral HPLC [13] revealed that astaxanthin fraction in sea angels was consisted of only (3*S*,3<sup>ȝ</sup>*S*) optical isomers. 

Diatoxanthin (**9**). ESI-TOF MS: *m/z* 567.4225 [M + H]+ (calcd for C40H55O2, 567.4202); UV-VIS: (426), 451, 478 nm. 

Pectenol A (**10**). ESI-TOF MS: *m/z* 583.4173 [M + H]+ (calcd for C40H55O3, 583.4152); UV-VIS: (426), 451 478 nm. 

Pectenol B (**11**). ESI-TOF MS: *m/z* 583.4170 [M + H]+ (calcd for C40H55O3, 583.4152); UV-VIS: (426), 451, 478 nm. 

Pectenolone (**12**). ESI-TOF MS: *m/z* 581.3983 [M + H]+ (calcd for C40H53O3, 581.3995); UV-VIS: 460 nm; 1H-NMR (CDCl3, 500 MHz) Έ 1.15 (H3-16<sup>ȝ</sup>, s), 1.20 (H3- <sup>17</sup><sup>ȝ</sup>, s), 1.21 (H3-17, s), 1.32 (H3-16, s), 1.45 (H-2ȝΆ, dd, *J* = 12, 11), 1.82 (H-2Ά, d, *J* = 13, 13), 1.84 (H-2ȝ΅, ddd, *J* = 12, 4, 1.5), 1.92 (H3-19<sup>ȝ</sup>, s), 1.95 (H3-19, s), 2.07 (H-2ȝΆ, dd, *J* <sup>=</sup> 18, 10), 2.15 (H-2΅, dd, *J* = 13, 6), 2.43 (H-4ȝ΅, ddd, *J* = 18, 6, 1.5), 3.68 (OH-3, d, *J* = 2), 3.99 (H-3<sup>ȝ</sup>, m), 4.32 (H-3, ddd, *J* = 13, 6, 2), 6.22 (H-7, d, *J* = 16), 6,28 (H-14<sup>ȝ</sup>, d, *J* = 11), 6.30 (H-10, d, *J* = 11), 6.30 (H-14, d, *J* = 11), 6.36 (H-12<sup>ȝ</sup>, d, *J* = 15), 6.43 (H-8, d, *J* = 16), 6.45 (H-12, d, *J* = 15), 6.45 (H-10<sup>ȝ</sup>, d, *J* = 11), 6.53 (H-11<sup>ȝ</sup>, dd, *J* = 15, 11), 6.63 (H-15 and H-15<sup>ȝ</sup>, m), 6.65 (H-11, dd, *J* = 15, 11). 

4ȝ-Hydroxypectenolone (**13**). ESI-TOF MS: *m/z* 597.3942 [M + H]+ (calcd for C40H53O4, 597.3944); UV-VIS: 460 nm. 

7,8-Didehydroastaxanthin (**14**). ESI-TOF MS: *m/z* 595.3789 [M + H]+ (calcd for C40H51O4, 595.3787); UV-VIS: 474 nm. 

Alloxanthin (**15**). ESI-TOF MS: *m/z* 565.4028 [M + H]+ (calcd for C40H53O2, 565.4046); UV-VIS: (426), 451 478 nm. 

4-Ketoalloxanthin (**16**). ESI-TOF MS: *m/z* 579.3851 [M + H]+ (calcd for C40H51O3, 579.3838); UV-VIS: 460 nm. 

4ȝ-Hydroxy-4-Ketoalloxanthin (**17**). ESI-TOF MS: *m/z* 595.3801 [M + H]+ (calcd for C40H51O4,595.3787); UV-VIS: 469 nm. 

7,8,7<sup>ȝ</sup>,8<sup>ȝ</sup>-Tetradehydroastaxanthin (**18**). ESI-TOF MS: *m/z* 593.3649 [M + H]+ (calcd for C40H49O4,593.3631); UV-VIS: 476 nm. 

Diadinoxanthin (**19**). ESI-TOF MS: *m/z* 583.4173 [M + H]+ (calcd for C40H55O3, 583.4151); UV-VIS: 420, 433, 470 nm. 

Fucoxanthin (**20**). ESI-TOF MS: *m/z* 659.4333 [M + H]+ (calcd for C42H59O6,659.4312); UV-VIS: 445, 470 nm. 
