IIMYC   23581
INSTITUTO DE INVESTIGACIONES MARINAS Y COSTERAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
UV radiation effect on survival and growth and Quantification on free radicals in postlarval stages of the red shrimp Pleoticus muelleri
Autor/es:
JORGE L FENUCCI ; MARIA ALEJANDRA MARCOVAL; A.C DÏ¿½AZ; SUSANA VELURTAS
Lugar:
Sesttle, Washington
Reunión:
Conferencia; Aquaculture America 2014; 2014
Institución organizadora:
World aquaculture Society
Resumen:
The red shrimp Pleoticus muelleri is a commercially-important coastal species, distributed from Southern Brazil to Patagonia (23-50 �S). High latitudes in the S. Hemisphere, have experienced higher levels of UV-B radiation (280-315 nm), due to the progressive depletion of the ozone layer, one of the most important anthropogenic climatic changes. The larval period of marine organisms represents a key stage in their life cycle, upon which reduced growth and survival might translate into a potential decline in adult populations. The aim of this study was to determine the effect of ultraviolet radiation (UVR) on survival, development, growth, and to determine free radical scavenging properties in postlarval stages. The larvae came from the University Mar del Plata?s hatchery. Mysis III (MIII) incubated at a 25L-1 density in 5-L tanks under controlled conditions of temperature, pH, salinity, and fed with Artemia persimilis nauplii supplemented with Pavlova sp. They were exposed by triplicate to three radiation treatments: a) M-UVR: received the total radiation spectrum (UVR 280-400nm + PAR 400-700nm); b) M-PAR: covered with Ultraphan film (opaque to UVR, Digefra, 50% transmission at 395 nm) to receive only PAR. c) Controls: placed in semi-darkness. Additionally, two experimental dietary treatments were considered: a) A-UVR, live food incubated under the UVR radiation regime; and b) A-PAR, incubated under the PAR regime. Larval quality index (Qi) was calculated and antioxidant activity was quantified measuring the free-radical 2,2-diphenyl-1- picrylhydrazyl (DPPH) by electron paramagnetic resonance (EPR). All treatments reached the postlarvae of 8 days (PL8), except M-UVR treatment fed A-PAR, whose survival was 0% from the MIII to PL1 stages. The M-UVR treatment fed A-UVR, together with the M-PAR treatment fed A-PAR, 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 controls reached highest survival of 90%. The induction of the synthesis of UV-absorbing compounds was detected spectrophotometrically in A. persimilis, and postlarvae subject to UVR treatments. The DPPH signal on PL8 (Fig. 1) decayed drastically in M-UVR fed A-UVR treatment, within 5 min and after 1 h the DPPH remnant was about 20%.Moreover the controls and M-PAR fed A-PAR treatments decayed 80-90% at the same time. Fig 1. DPPH reaction kinetics in the tissue homogenates on PL8. We conclude that UV- absorbing compounds bioaccumulated through the diet could contribute to a photoprotective effect under UVR stress. The major antioxidant activity observed on postlarvae M-UVR fed A-UVR suggest that the mycosporine like-aminoacids provide an effective benefit on photophysiology of these consumers.