Fluoxetine can make marine organisms unhappy: a study on the sub-lethal effects on marine invertebrates

The environmental effects caused by selective serotonin reuptake inhibitor drugs have been investigated for marine organisms and coastal ecosystems but are scarce in neotropical organisms. This investigation aimed to evaluate the sublethal effects of fluoxetine on the embryonic development of the sea urchin Echinometra lucunter and the survival and swimming behavior of the brine shrimp Artemia sp. The organisms were exposed to four different concentrations of fluoxetine (30, 300, 3000 and 30000 ng L-1) and to a negative control (filtered seawater), following the respective standard testing protocols. We verified a significant reduction of the embryos development to pluteus larvae, starting from 3000 ng L-1 (54.0±10.9% normal larvae), in comparison with the controls (83.5±3.1%). The non-observed effect concentration (NOEC) was estimated at 300 ng L-1, and the lowest observed effect concentration (LOEC) was 3000 ng L-1. In the behavior tests with Artemia sp, no significant adverse effects were reported for mobility, swimming speed and inactivity time. These results show that Fluoxetine can interfere on the development of species like the sea urchin E. lucunter, but short term exposure did not affected the swimming behavior of the brine shrimp Artemia sp. Fluoxetine presents thus a potential to affect marine biota and disrupt the equilibrium of the coastal ecosystems

Seawater carbonate chemistry and physiology of the sea-bob shrimp Xiphopenaeus kroyeri (Decapoda, Penaeidae)

Climate changes are altering the chemistry of the oceans, and knowing their effects on the biology of animals is urgent. Since the physiological responses of crustaceans may be different given the seasons of the year, this work evaluated the synergistic effect of ocean acidification and seasonality on the physiology of the sea-bob shrimp, Xiphopenaeus kroyeri. Experimental groups were exposed for 5 days to two levels of pH, representing present-day mean ambient conditions (pH 8.0) and distant-future conditions (pH 7.3) during the summer and winter. Metabolism, nitrogen excretion, energy type and storage were determined, respectively, by oxygen consumption, ammonia excretion, atomic ratio O/N and hepatosomatic index. The reduction of pH resulted in a decrease of about 30% in the X. kroyeri metabolism during the summer and winter. Nitrogen excretion (reduction of 40%) and hepatosomatic index (increase of 120%) showed to be altered in animals exposed to reduced pH only throughout summer. Regardless of pH and seasons of the year, animals use mainly proteins as energy substrate and they do not show mortality. The increase of the hepatosomatic index, indicator of the accumulation of energy reserves, associated with metabolism reduction, suggests the suppression of activities that demand energy expenditure. The consequences of the physiological alterations observed may include decreases in growth and reproduction rate and displacement of populations to more appropriate conditions. The results might be associated with a set of factors resulting from the exposure to reduced pH, the synergy between pH and temperature, but also with a pattern of different physiological responses that may occur according to seasonality