The sublethal effects of (2,4-Dichlorophenoxy) acetic acid (2,4-D) on narrow-clawed crayfish (Astacus leptodactylus Eschscholtz, 1823)

Abstract

2,4-D is a widely used phenoxy herbicide, potentially toxic to humans and biota. The objective of the present study was to reveal short term sublethal effects of 2,4-D on narrow-clawed freshwater crayfish (Astacus leptodactylus Eschscholtz, 1823), based on histology, total haemocyte counts, selected haemolymph parameters, and oxidative stress parameters. In the laboratory conditions crayfish specimens were exposed to 9 mg L -1 of 2,4-D for one week. Experiments were conducted under semi-static conditions in 20 L-capacity aquaria where 10 freshwater crayfish were stocked per aquarium. Exposure (experimental) and control groups were used and the experiments were repeated two times. No mortality and behavioural changes were recorded during the experiments. Total haemocyte counts decreased significantly, while haemolymph glucose levels increased (P<0.05), when compared to the control group. Haemolymph levels of calcium, chloride, sodium, potassium, magnesium, total protein, and lactate did not change. Exposure resulted with increased levels of malondialdehyde (MDA) only in hepatopancreas. However, results of gill FOX assay showed a significant decrease in oxidative stress parameters (P<0.05). MDA levels of gill and abdominal muscle tissues and FOX levels of hepatopancreas and abdominal muscle tissues did not change when compared to the control group. Significant histopathological alterations were observed both in hepatopancreas (multifocal deformations in tubule lumen) and gill tissue (melanisation of gill lamella). Exposure of crayfish even to a sublethal concentration of 2,4-D alters histopathology and lipid peroxidation due to stress. Biomarkers studied here seem to be useful for the assessment of adverse/toxic effects of pesticides on non-target, indicator aquatic organisms.KEY WORDS: haemolymph; herbicide; histology; oxidative stress; toxicity T h e f i r s t s u c c e s s f u l s e l e c t i v e h e r b i c i d e , 2,4-dichlorophenoxy acetic acid (2,4-D), was developed in 1946. It belongs to the phenoxy herbicide family and is still one of the systemic herbicides widely used to control many types of broadleaf weeds (1). It is used to control aquatic vegetation, in pasture and rangeland applications, in cultivated agriculture, forest management, home, and garden. It acts by sustaining high levels of the plant hormone auxin, which results in overstimulation of plant growth and death. In addition to this, it causes changes in the animal nervous system based on receptor interaction/interference of acetylcholine. Furthermore, it inhibits the acetyl cholinesterase (AChE) activity and increases the level of serotonin.Available data on 2,4-D toxicity on aquatic organisms mostly rely on the reports of its acute toxic effects observed in different fish species. Oruc and Uner (4) studied the combined effects of azinphosmethyl and 2,4-D on Oreochromis niloticus to clarify the mode of its action on the cellular defence system. Farah et al. (5) (8); for catfish (Clarias batrachus) by studying micronuclei and erythrocyte alt...

Ecological Toxicity of Cyantraniliprole against Procambarus clarkii: Histopathology, Oxidative Stress, and Intestinal Microbiota

“…Since the hepatopancreas is the main target organ for pollutants, such as pesticides, tissue damage in the hepatopancreas after cyantraniliprole exposure varied in a concentration-dependent manner. A similar phenomenon was observed in crayfish exposed to maduramicin, and toxicant-induced hepatopancreatic damage was observed in different crayfish species, such as Cherax destructor and Astacus leptodactylus. , P. clarkia intestines, possessing several longitudinal ridges with cuticula, are the main excretory organs, and they digest, absorb, and excrete exogenous pollutants, such as pesticides and heavy metals.…”

“…A similar phenomenon was observed in crayfish exposed to maduramicin, and toxicant-induced hepatopancreatic damage was observed in different crayfish species, such as Cherax destructor and Astacus leptodactylus. 32,33 P. clarkia intestines, possessing several longitudinal ridges with cuticula, are the main excretory organs, and they digest, absorb, and excrete exogenous pollutants, such as pesticides and heavy metals. In this study, the intestine of P. clarkii exposed to cyantraniliprole exhibited epithelial cell separation from the stratum corneum, bladder cell vacuolization, and fractured longitudinal muscles.…”

Comparative study on immunological responses in Scylla serrata and Litopenaeus vannamei upon WSSV infection

“…The total circulating haemocyte number is a known stress indicator, but this parameter varies non-specifically according to the environment, chemical and physico-chemical stress and the alteration in the number of haemocytes in crustaceans suggests that immune system is altered (Benli et al, 2016). Hence, the total haemocyte count (THC) is a useful indicator of crab's health.…”

Avaliação dos efeitos ecotoxicológicos da vinhaça e de agrotóxicos utilizados na produção da cana-de-açúcar sobre espécies aquáticas tropicais

“…No caso de herbicidas, por exemplo, que possuem um mecanismo de ação para as células vegetais, é difícil definir ação direta no nível molecular para outros seres vivos, porque existem vários mecanismos diretos e indiretos que podem ser ativados após a exposição (BUKOWSKA, 2006). Neurotoxicidade, genotoxicidade, histopatologia, dano bioquímico e ruptura endócrina (MARTINEZ-TABCHE; MADRIGAL-BUJAIDAR; NEGRETE, 2004;XIE et al, 2005;LAJMANOVICH et al, 2013;MENEZES et al, 2015;BENLI et al, 2016) são exemplos de efeitos de 2,4-D encontrados em organismos aquáticos.…”