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Corallium rubrum is the most famous and precious coral due to the intense characteristic red colour of its skeleton. We have determined the presence of carotenoids in natural samples of C. rubrum from Marseille, Riou, and investigated their chemical composition. Analysis was performed both on soft tissues and hard tissues including spicules and skeleton. Since hard tissues are made of a mineral fraction and an organic fraction obtained after demineralization, extraction was performed both with and without demineralization by EDTA. The extracts were analyzed by complementary methods of TLC, HPLC/DAD and HPLC/MS. The components were separated by RP-18 chromatography column using acetonitrile/methanol for HPLC/DAD and acetonitrile/water gradient for HPLC/MS analysis. Our results give the first evidence of the presence of canthaxanthin, 4,4′-diketo-β-carotene, as the major carotenoid in all samples. Spicules exhibited higher content in carotenoids than skeleton. Demineralization treatment improved the efficiency of carotenoid extraction by an average factor of 5 and showed that organic matrix contains canthaxanthin.

The epidermal tissues, ovaries, viscera, gut contents, and the diet of Holothuria atra (Jaeger), collected from the Great Barrier Reef (GBR), Australia, just prior to spawning, contained carotenoid pigments, mycosporine-like amino acids (MAAs) and three other metabolites in varying proportions. Mycosporine-glycine (mycosporine-gly), palythine, asterina-330, shinorine, mycosporine-2-gly, porphyra-334, and palythinol were present in the epidermal tissues. Mycosporine-gly was the major MAA in the epidermal tissues, gut contents and the diet, and the only MAA present in the ripe ovaries and the viscera. Gadusol, a metabolite with antioxidant properties, which co-occurs with MAAs, and in certain instances with trace amounts of 6-deoxygadusol in unfertilised and fertilised eggs and developing larvae of some marine invertebrates and vertebrates, was absent from H. atra. However, 6-deoxygadusol, with similar physical and chemical properties to gadusol, and the proposed biosynthetic precursor of MAAs, was present, but only in the ovaries. This is first report of the presence of this proposed biogenetic precursor of MAAs in significant amounts in a marine invertebrate. Approximately 90% of the total carotenoids of the epidermal tissues, ovaries and viscera of H. atra are highly oxidised, the main component being astaxanthin followed by canthaxanthin. These were the major carotenoids present in the ovaries and the total carotenoid content was highest in the ovaries. β-carotene, a common egg carotenoid, was present in trace quantities in the ovaries but, along with the xanthophylls lutein and zeaxanthin, it occurred in significant amounts in the gut contents and the diet of H. atra. Carotenoid patterns in the epidermal tissues and viscera were strikingly similar, containing β-carotene, canthaxanthin, astaxanthin, zeaxanthin, lutein, phoenicoxanthin and echinenone. The alkaloids homarine and isomeric trigonelline, (structurally unrelated to MAAs) and 6-deoxygadusol were present only in the ovaries and the viscera. It is suggested that these metabolites and pigments are either involved with photoprotection or reproduction, or associated with both processes. The origin, biogenetic relationships and the roles of these metabolites and pigments in H. atra are discussed.

Nyctiphanes australis contained, on a dry weight basis, an average of 52% crude protein and 5.0 to 9.5% lipid. The fatty acid profile of N. australis was markedly unsaturated, with a mean total ω3 fatty acid content of 48.6±2.4% of total fatty acids. N. australis contained high levels of the essential long-chain polyunsaturated fatty acids eicosapentaenoic (EPA, 20:5ω3) and docosahexaencic (DHA, 22:6ω3), ranging from 16.6 to 36.5% and 11.1 to 24.8%, respectively. The concentration of total carotenoids ranged from 137 to 302 μg g−1 dry wt, with no significant differences in concentrations found with season or life stage. The carotenoids were comprised of 79.5% astaxanthin and 20.5% canthaxanthin. The lipid and pigment compositions of N. australis suggest that the species could serve as a suitable feed source for cultured salmonids. Like other euphausiids, N. australis contained high levels of fluoride, with a seasonal range between 277 and 3507 μg g−1 dry wt. The high fluoride levels found in N. australis would not detract from its potential as a feed source for salmonids because ingested fluoride is largely absorbed by the skeleton.

Carotenoid pigments were used as markers to investigate the sources of energy to two deep-sea hydrothermal vent communities. Specimens of the hydrothermal-vent brachyuran crabBythograea thermydron were collected at 2 500 m depth from the Rose Garden vent site in the Galapagos Rift Valley in February, November and December 1979, and 2 600 m depth on the East Pacific Rise at 21°N in May 1982. Four carotenoids (astaxanthin, canthaxanthin, echinenone and beta-carotene) have been identified as the pigments responsible for the red color of the eggs of the crabs from the Galapagos Rift site. Consistent with the fact that animals are unable to synthesize carotenoidsde novo, precursors were not present in the crabs' tissues, affirming that these pigments are of dietary origin. The number of ovigerous female crabs and the concentrations of carotenoids in the eggs suggest a readily available source of these pigments in the Galapagos vent environment. In contrast, the developing eggs ofB. thermydron from the 21°N vent site were cream-colored, with only trace quantites of carotenoids and fewer types of carotenoids. Analysis of carotenoid distribution in both females and males in these two populations indicates a very low level of carotenoids in the diet of the 21°N vent crabs, and reflects differences in trophic interactions and primary production at the two vent sites. The few types and low concentration of carotenoids inB. thermydron indicate a diet that is different from non-vent, deep-sea crustaceans. We hypothesize that the source of carotenoids are bacteria within the vent community, and not ultimately from photosynthetic production.

The carotenoids in the crustaceans Eupagurus bernhardus, Hyas coarctatus and Upogebia deltaura from the Gullmar fjord (Bohuslan, Sweden) were investigated. Their presence was determined by means of columnar and thin-layer chromatography. The following carotenoids were found — in E. bernhardus: s-carotene, canthaxanthin, lutein epoxy, 4-keto-4-ethoxy-s-carotene, zeaxanthin, astaxanthin and astacene; in H. coarctatus: cryptoxanthin, 4-keto-4-hydroxy-s-carotene, lutein (pure and epoxy), astaxanthin, and astacene; in U. deltaura: γ-carotene, canthaxanthin, gazaniaxanthin?, isozeaxanthin, cryptoxanthin, 4-keto-4-hydroxy-s-carotene, zeaxanthin, astaxanthin and astacene.

The author investigated the carotenoids in the jelly-fish Aurelia aurita (L.), from the Baltic Sea. By means of columnar and thin-layer chromatography, the following carotenoids were found to be present in that species: β-carotene, echinenone isocryptoxanthin, canthaxanthin, lulein, zeaxanthin, astaxanthin and astacene.

The authors investigated the carotenoids in the hermit crab, Clibanarius misanthropus (Risso), from the Black Sea. By means of columnar and thin-layer chromatography the following carotenoids were found to be present in that species; β-carotene, canthaxanthin, lutein, astaxanthin and some kind of polioxyxanthophill.

Investigations have been carried out on the carotenoids in the anthozoan coelenteratesAlcyonium digitatum (yellow and brown specimens) andPennatula phosphorea from the Gullmar fjord (Bohuslan, Sweden). The presence of the carotenoids was determined by means of columnar and thin-layer chromatography. The following carotenoids were found inA. digitatum: canthaxanthin, phoenicoxanthin and phoeniconone, isozeaxanthin, zeaxanthin, astaxanthin, and astacene;P. phosphorea contained canthaxanthin, isozeaxanthin, zeaxanthin, astaxanthin, and astacene.

Investigations have been made on the carotenoids in the marine amphipod Hyale perieri (Lucas) from the Black Sea. The presence of the carotenoids β-carotene, canthaxanthin, lutein, neoxanthin and astaxanthin was determined by means of columnar and thin-layer chromatography. It is highly probable that violaxanthin is also present in H. perieri.

Investigations have been carried out on the carotenoids in Leander (Palaemon) serratus (Pennant) and Nephrops norvegicus (L.) (Crustacea: Decapoda) from the Adriatic Sea. The presence of the carotenoids was determined by means of columnar and thin-layer chromatography. The following carotenoids were found: Leander serratus: β-carotene, echinenone, isocryptoxanthin, cryptoxanthin, canthaxanthin, lutein, isozeaxanthin, zeaxanthin, astaxanthin, and astacene; Nephrops norvegicus: β-carotene, lutein, zeaxanthin, astaxanthin, and astacene.