Articles
Impaired growth and erythrocyte nuclear lesions of immature Oreochromis niloticus exposed to waterborne crude oil: Persistent responses
Authors:
S. H. N. P. Gunawickrama,
LK
About S. H. N. P.
General Sir John Kotelawala Defence University, Kandawala Road, Ratmalana 10380
P. D. S. M. Panawala,
LK
About P. D. S. M.
Department of Zoology, Faculty of Science, University of Ruhuna, Matara 81000
K. B. S. Gunawickrama
LK
About K. B. S.
Department of Zoology, Faculty of Science, University of Ruhuna, Matara 81000
Abstract
Crude oil impact studies have largely been limited to marine setting and it hampers the understanding and predictability pertaining to freshwater environments following contamination episodes. Growth and erythrocyte nuclear abnormalities (ENA) were followed in freshwater fish Oreochromis niloticus experimentally exposed to crude oil (Arabian light) dispersed in water. Study comprised of a control (no crude oil in water), and two experimental groups with 5 µL/L and 25 µL/L crude oil dispersed in water (5 ppm and 25 ppm respectively), and involved continuous exposure of fish (35 fish/tank in triplicate) with static renewal over a 90-day period. Growth was estimated serially at 18-day intervals (n=40-60). Both exposure groups reduced (p<0.05) weight-based and length-based growth rates and specific growth rates. Giemsa-stained peripheral blood and head kidney smears on day 90 (n=6) showed increased (p<0.05) micronuclei, nuclear buds, fragmented apoptotic nuclei and other types of ENA frequencies (per 1000 RBC) in the fish exposed to 25 ppm crude oil. Moreover, crude oil induced ENA levels were quantitatively different (p<0.05) between the peripheral blood and head kidney. Results show that crude oil hampers growth and sustains elevated ENA of O. niloticus juveniles in freshwater environment.
How to Cite:
Gunawickrama, S.H.N.P., Panawala, P.D.S.M. and Gunawickrama, K.B.S., 2016. Impaired growth and erythrocyte nuclear lesions of immature Oreochromis niloticus exposed to waterborne crude oil: Persistent responses. Sri Lanka Journal of Aquatic Sciences, 21(2), pp.113–124. DOI: http://doi.org/10.4038/sljas.v21i2.7507
Published on
24 Jun 2016.
Peer Reviewed
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