Development of survivorship model for UV-B irradiated Catla catla larvae

Abstract

A survivorship model was developed for UV-B irradiated Catla catla (17 days) larvae with the help of Kaplan and Meier Product-Limit (PL) method. Larvae were exposed to UV-B radiation (145 lW cm -2 ) for three different exposure times: 5, 10 and 15 min on every other day. The mean survival time of fish was calculated for each treatment using uncensored and censored survival data during 74 days study period. The mean uncensored and censored survival data for the 5-min exposed fish were 7 and 43, respectively. In 10-min exposure period, the uncensored and censored survival data were 19 and 31, respectively. During maximum exposure of 15 min, the uncensored survival data was 20 and censored data was 30. The mean survival time of fish calculated using PL estimate in 5, 10 and 15-min exposure treatments were 69.61 ± 0.50, 65.25 ± 0.96 and 60.60 ± 1.55 days, respectively. The mean survival time showed a decreasing trend with the increase of exposure period. The survival time was significantly (P < 0.001) higher in 5-min exposure treatment than others. This is clear from the present study that the exposure of UV-B radiation affects the survival rate of surface feeder catla larvae.

Simulation study of natural UV-B radiation on Catla catla and its impact on physiology, oxidative stress, Hsp 70 and DNA fragmentation

“…In our earlier studies, an inverse relationship was found between the time of exposure to UV-B and survival rate of catla [32] and rohu Labeo rohita larvae [6,7]. Present study showed that UV-B radiation penetrated the tissue and affected catla even after proper pigmentation.…”

Effect of UV-B radiations on mortality and enzymes level in fish larvae of Tor tor and Schizothorax richardsonii on laboratory scale

“…Alemanni et al, (2003) also demonstrated an increase in oxygen consumption rate and restless behavior of juvenile rainbow trout (Oncorhynchus mykiss) due to the effect of UV radiations. Sharma et al, (2008) showed that fish survivorship model based on the exposure of UV-B radiation affects the survival rate of surface feeder fish, Catla catla larvae. UV radiations along with other ecological stressors are also harmful for fish species in aquatic ecosystem.…”

Impact of UV-B Radiation on the Physiology of Freshwater Carp Labeo rohita Larvae and Evaluation of UV-B Protective Properties of Seeds of Achyranthes aspera and Vitamin C

“…Photoprotective pigments (MAAs, carotenoids), antioxidant defense compounds (flavonoids, vitamins C and E), and cell cycle development genes are some molecules involved in UV radiation defense [10]. We have observed the damaging effect of UV-B on freshwater carp larvae in our earlier studies [31,33,34]. Dietary supplementation of antioxidant vitamin C and plant ingredient may be beneficial for fish larvae to face the challenge of exposure of harmful UV-B irradiation.…”

“…The embryos and larvae of many species are more sensitive to environmental stressors like UV-B compared to their later life stages [2,7]. Sharma et al [33] reported that exposure of UV-B affected the survival rate of catla, Catla catla larvae under laboratory conditions. UV-B radiation affected the skin and eyes of ayu, Plecoglossus altivelius larvae, and gills of catla larvae [31,32].…”