CONICET | Buscador de Institutos y Recursos Humanos

The aim of this study was to determine direct- and indirect effects of ultraviolet radiation (UVR) on survival, development, and bioaccumulation of UV-absorbing compounds through the diet of larvae and postlarvae of the Argentine red shrimp, Pleoticus muelleri. Mysis I larvae (MI) were incubated at a density of 200 L-1 in 4-L parabolic tanks under controlled temperature, pH and salinity conditions. Larvae were exposed to two radiation treatments: M-PAB uncovered containers exposed to the total radiation spectrum (UVR 280-400 nm + PAR 400-700 nm); and M-PAR, containers covered with Ultraphan film (opaque to UVR, Digefra, 50% transmission at 395 nm) to received only PAR. UVR was generated from Q-Pannel UVA-340 lamps, and fluorescent bulbs provided PAR. Additionally, two experimental dietary treatments were considered: A-PAB, consisting of Artemia salina nauplii supplemented with Pavlova sp. (microalgae commonly used in aquaculture and known to produce UV-absorbing compounds), both incubated under the PAB radiation regime; and A-PAR, consisting of nauplii of A. salina, and Pavlova sp., incubated under the PAR regime. All experiments were tested in triplicate groups. Larval quality index (Qi) was calculated. All treatments reached the postlarvae of 8 days (Pl8), except M-PAB treatment fed A-PAR, whose survival was 0 % in the transition from the MIII to Pl1 stages. The M-PAB treatment fed A-PAB, together with the M-PAR treatment fed A-PAB, presented the higher survival rates (70 and 75 %, respectively), congruently with a 37 and 41 % increase in size. Moreover, in both combinations, larvae presented Qi = 70 %. The induction of the synthesis of UV- absorbing compounds was detected spectrophotometrically in the microalgae, in A. salina, and in shrimp postlarvae subject to PAB treatments. We conclude that UV- absorbing compounds could bioaccumulate through the diet, possibly contributing to a photoprotective effect under UVR stress.