Locomotor Behavioral Response of Mosquitofish (Gambusia affinis) to Subacute Mercury Stress Monitored by Video Tracking System

• Published in: Drug and chemical toxicology (New York, N.Y. 1978) N.Y. 1978), 2007-01, Vol.30 (4), p.383-397
• Main Authors: Jakka, N. M., Gnaneshwar Rao, T., Venkateswara Rao, J.
• Format: Article
• Language: English
• Subjects: Agnatha. Pisces; Animal, plant and microbial ecology; Animals; Applied ecology; Behavior; Behavior, Animal - drug effects; Bioaccumulation; Biological and medical sciences; Chemical and industrial products toxicology. Toxic occupational diseases; Culicidae; Cyprinodontiformes - growth & development; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on vertebrates; Fundamental and applied biological sciences. Psychology; Gambusia affinis; Gill; Gills - drug effects; Gills - pathology; Lethal Dose 50; Medical sciences; Mercuric Chloride - pharmacokinetics; Mercuric Chloride - toxicity; Mercury; Metals and various inorganic compounds; Motor Activity - drug effects; Tissue Distribution; Toxicology; Video tracking system; Water Pollutants, Chemical - pharmacokinetics; Water Pollutants, Chemical - toxicity
• ISSN: 0148-0545; 1525-6014
• DOI: 10.1080/01480540701522551

Locomotor behavior is commonly affected by contaminants, and the pattern of fish swimming is a highly organized species-specific response. In the current study, we examined the locomotor behavioral response of the mosquitofish, Gambusia affinis, which was exposed to a sublethal concentration (LC5, 20 μg L) of mercuric chloride (HgCl2) for 28 days and monitored using a computer vision system. The EthoVision video tracking system for automation of behavioral studies at regular intervals revealed abnormal locomotor behavior such as reduction in swimming speed (cm s) and distance traveled per unit time. The effects of this metal on the gill morphology and bioaccumulation in different body parts were also investigated. High-resolution microscopy studies revealed abnormal gill morphology, with fusion of primary lamellae along with deep lesions and erosions in the secondary lamellae. The bioaccumulation concentrations in head, body, and viscera were determined by cold vapor atomic absorption spectrometric technique at regular intervals. The results indicated that the accumulation of mercury was the highest in viscera followed by head and body, with bioconcentration factors (BCFs) of 3.99, 2.18, and 1.57 and uptake rate constants (k1) of 17.91, 11.02, and 8.13, respectively. These observations indicate that alterations in fish behavior under subacute stress can provide important information useful in predicting the stress.