Parental Dietary β -Carotene Intake in Lytechinus variegatus Affects Early Development of Offspring Exposed to UV Radiation
Planktonic embryos utilize photo-protective mechanisms to minimize the deleterious effects of solar ultraviolet radiation (UVR) exposure. It was hypothesized that embryos from parents who received supplemental β-carotene in their diets would be more resistant to the effects of UVR than embryos from parents who received no supplementation. Adult Lytechinus variegatus broodstock with gonads in the growing phase were fed diets either with or without supplemental β-carotene for 5 months and subsequently induced to spawn. Fertilized eggs were collected from each feed treatment and exposed to differing intensities of UVA (0-4 J/m2) or UVB (0-100 mJ/cm2) radiation. Larval mortality counts and developmental status were recorded at 34 and 55 hours post-fertilization and compared between feed treatments. Embryos derived from sea urchins consuming supplemental β-carotene developed at a slower rate than those whose parents did not consume supplemental β-carotene. Increasing intensities of UVA and UVB radiation were positively correlated with larval mortality in both dietary treatments. UVB induced higher mortality than UVA. Larval mortality in the β-carotene supplemented treatment was significantly higher than the non-supplemented treatment. These data suggest that dietary supplements of carotenoid do not provide photo-protection and may enhance, through unknown mechanisms, the deleterious effects of UV exposure.