In vivo DNA damage in gill, haemolymph and muscle cells of whiteleg shrimp Litopenaeus vannamei on exposure to organophosphorus pesticide

Abstract

In response to growing worldwide market demand, intensive shrimp farming, particularly of whiteleg shrimp Litopenaeus vannamei, has expanded tremendously. The present study investigated induced DNA damage in gill (GL), haemolymph (HL) and muscle (ML) cells in juveniles of L. vannamei (length: 52.2 ± 6.4 mm; weight: 1.78 ± 0.5 g; mean ± SD) exposed to 2 sublethal (SL) concentrations, SL1 (0.36 µg l -1 ) and SL2 (0.18 µg l -1 ), of the organophosphorus pesticide chlorpyrifos (CPF) during 21 d of exposure (DoE). The magnitude of DNA damage (% tail DNA) as measured by the comet assay at specified intervals (3, 7, 14 and 21 DoE) was found to be tissue specific and time and dose dependent (p < 0.05). At the end of the experiment, at 21 DoE, % tail DNA damage was relatively higher at SL1 (53.61 ± 8.71, 49.36 ± 3.42 and 32.40 ± 4.97%) compared to SL2 (39.25 ± 3.90, 32.22 ± 4.21 and 22.66 ± 2.85%) in GL, HL and ML cells, respectively. No significant differences in water quality parameters were found among treated and control aquaria. The significant reduction in specific growth rates (% growth d -1 ) observed in exposed shrimps indicated that SL concentrations of CPF negatively impacted growth in L. vannamei juveniles. A very low 96 h median lethal concentration (1.44 µg l -1 ) indicated sensitivity of L. vannamei juveniles to CPF, suggesting that the species could be used as a bioindicator for assessing pesticide pollution. The study results highlight the implications of extending the farming of L. vannamei to low-salinity inland areas adjacent to traditional agricultural fields.

Sperm Quality Assessment of White Shrimp (Litopenaeus Vannamei) Broodstock using Comet Assay

“…This indicates that the degree of sperm DNA damage inversely correlates with the fertilization rate of the shrimp. This result is in agreement with previous reports showing that sperm DNA fragmentation is associated with fertility rate of the shrimp [47,48,61,62]. The studies provide evidence that DNA damage within sperm could potentially affect the ability of the sperm to properly fertilize an egg, leading to lower fertilization success.…”

“…Many studies have demonstrated that DNA fragmentation of germ cells from a number of invertebrates can be reliably detected using the comet assay [44][45][46][47][48]. Shrimp sperm integrity can be easily disturbed by various environmental factors and husbandry practices which may potentially impact fertilization success [49][50][51], therefore, the quality of sperm cannot be verified entirely by external morphological characteristics.…”