MYCOSPORINE-LIKE AMINO-ACIDS IN 38 SPECIES OF SUBTIDAL MARINE ORGANISMS FROM MCMURDO SOUND, ANTARCTICA

Mycosporine-like amino acids (MAAs) that absorb UV radiation (310-360 nm) were investigated in 34 species of benthic marine invertebrates (f ourteen sponges, two cnidarians, one nemertean, four molluscs, one bry ozoan, two arthropods, eight echinoderms and two tunicates), two speci es of benthic fish and two species of red algae collected during the s pring of 1992 from McMurdo Sound. In addition, MAAs were measured in t he ripe ovaries, testes and brooded juveniles of four species of echin oderms. While 90% of the species had MAAs in their tissues, both quant itative and qualitative measurements reflected a general lack of UV pr otectants among these fauna. Eight MAAs were detected among the specie s examined, but only four of these (mycosporine-glycine, shinorine, po rphyra-334 and palythine) occurred in any appreciable number of the sp ecies. Palythinol only occurred in the sponge Isodictya erinacea and a sterina-330 and palythene only occurred in the red alga Iridaea cordat a. MAAs were detected in the ripe ovaries and testes of the sea urchin Sterechinus neumayeri and the ripe ovaries and brooded young of the s ea cucumber Cucumaria ferrari. Low levels and abundances of MAAs may r eflect a reduced need for UV protectants in marine organisms inhabitin g subtidal (>20 m depth) benthic environments that experience seasonal sea-ice cover. Low concentrations of MAAs may also be a function of d iet, since the majority of benthic species present in McMurdo Sound ar e not herbivorous.