The effects of fipronil and the photodegradation product fipronil desulfinyl on growth and gene expression in juvenile blue crabs, Callinectes sapidus, at different salinities

Abstract

Endocrine disrupting compounds (EDCs) are now widely established to be present in the environment at concentrations capable of affecting wild organisms. Although many studies have been conducted in fish, less is known about effects in invertebrates such as decapod crustaceans. Decapods are exposed to low concentrations of EDCs that may cause infertility, decreased growth, and developmental abnormalities. The objective herein was to evaluate effects of fipronil and its photodegradation product fipronil desulfinyl. Fipronil desulfinyl was detected in the eggs of the decapod Callinectes sapidus sampled off the coast of South Carolina. As such, to examine specific effects on C. sapidus exposed in early life, we exposed laboratory-reared juveniles to fipronil and fipronil desulfinyl for 96h at three nominal concentrations (0.01, 0.1, 0.5μg/l) and two different salinities (10, 30ppt). The size of individual crabs (weight, carapace width) and the expression of several genes critical to growth and reproduction were evaluated. Exposure to fipronil and fipronil desulfinyl resulted in significant size increases in all treatments compared to controls. Levels of expression for vitellogenin (Vtg), an egg yolk precursor, and the ecdysone receptor (EcR), which binds to ecdysteroids that control molting, were inversely correlated with increasing fipronil and fipronil desulfinyl concentrations. Effects on overall growth and on the expression of EcR and Vtg differ depending on the exposure salinity. The solubility of fipronil is demonstrated to decrease considerably at higher salinities. This suggests that fipronil and its photodegradation products may be more bioavailable to benthic organisms as salinity increases, as more chemical would partition to tissues. Our findings suggest that endocrine disruption is occurring through alterations to gene expression in C. sapidus populations exposed to environmental levels of fipronil, and that effects may be dependent upon the salinity at which exposure occurs.

Lethal and sub-lethal effects of the insecticide fipronil on juvenile brown shrimp Farfantepenaeus aztecus

“…On the contrary, Goff et al . 33 found that juvenile blue crabs Callinectes sapidus exposed to different nominal concentrations of fipronil and fipronil desulfinyl resulted in significant increases in growth in all treatments compared to controls in a short-term (96-h) experiment.…”

“…Fipronil desulfinyl (a photodegradation product of fipronil) was detected in the eggs of the Atlantic blue crab Callinectes sapidus off the coast of South Carolina (the Eastern coast of the United States), and it may be one of the causes of C . sapidus decline to the lowest historical levels over the past decade 33 . In Texas, fipronil has been reported in several recent studies conducted by the U.S. Geological Survey (USGS) and U.S. EPA in different cities including Houston-Galveston 48 , Austin 49 , San Antonio 50 , and College Station 51 , in concentrations ranging between 0.021 μg/L and 0.075 μg/L.…”

“…Several studies tested the toxicity of fipronil on non-target aquatic crustaceans such as blue crab Callinectes sapidus 33 , Chinese mitten crab Eriocheir sinensis and giant river prawn Macrobranchium rosenbergii 34 , red swamp crayfish Procambarus clarkia 35 , 36 , white river crayfish Procambarus zonangulus 35 , grass shrimp Palaemonetes pugio 37 , 38 , water flea Daphnia pulex 39 , and estuarine mysid shrimp Americamysis bahia 24 . However, the number of species studied is still limited, and most focused on lethal effects.…”

Developmental exposure to environmentally relevant concentrations of bifenthrin alters transcription of mTOR and ryanodine receptor-dependent signaling molecules and impairs predator avoidance behavior across early life stages in inland silversides (Menidia beryllina)

“…We further tested a suite of potential dose-response functions among concentrations, because fitting curves better allows for insights into dose-response patterns and also provides increased statistical power compared to testing for pairwise differences between treatments with an ANOVA / Tukey post-hoc approach (Cottingham et al, 2005; Brander et al, 2016; Goff et al, 2017). Therefore, per methods developed in Brander et al, 2016 and applied in Frank et al (2018), five different dose-response curves (linear regression, quadratic, sigmoidal, 5-parameter unimodal, and 6-parameter uni-modal) were tested for the best-fit of observed responses at all three concentrations and the solvent control (MeOH).…”

Sol-gel TiO2/Carbon Paste Electrode Nanocomposites for Electrochemical-assisted Sensing of Fipronil Pesticide

“…various kinds of attention in utilization pesticide because of the contaminant effect against living things [1,2]. One of pesticide used in agriculture is fipronil which is categorized as persistent organic pollutants (POPs) waste [3]. POPs is phenol pollutant waste in low-concentration where accumulated in the aquatic environment and contacted with living things.…”