Abstract
Fluctuating asymmetry (FA), often used as indicator of environmental stress, was evaluated in gill rakers and filaments of Labeo ogunensis from Ogun river, Southwest Nigeria. Mean length and weight of 13.68+1.28 cm and 59.40+17.48 g were respectively recorded. The gill rakers (t = -0.919) and filaments (t = -1.150) from both sides were not significantly different. The gill filaments recorded (0.31+2.42) higher incidence of fluctuating asymmetry (FA) compared with the gill rakers (0.21+1.58), signifying developmental interference in the population. Fish size and sex were observed to exert minimal influence on FA.Fluctuating asymmetry (FA), often used as indicator of environmental stress, was evaluated in gill rakers and filaments of Labeo ogunensis from Ogun river, Southwest Nigeria. Mean length and weight of 13.68+1.28 cm and 59.40+17.48 g were respectively recorded. The gill rakers (t = -0.919) and filaments (t = -1.150) from both sides were not significantly different. The gill filaments recorded (0.31+2.42) higher incidence of fluctuating asymmetry (FA) compared with the gill rakers (0.21+1.58), signifying developmental interference in the population. Fish size and sex were observed to exert minimal influence on FA.References
Adebisi, A.A. 1981 The physico-chemical hydrology of tropical seasonal river-upper Ogun river. Hydrobiologia 79: 157-165.
Bengtsson, B-E., Å. Bengtsson & M. Himberg. 1985 Fish deformities and pollution in some Swedish waters. Ambio 14(1): 32-35.
Felley, J. 1980 Analysis of morphology and asymmetry in bluegill sunfish (Lepomis macrochirus) in the Southeastern United States. Copeia 1: 18-29.
GESAMP. 1980 Monitoring biological variables related to marine pollution. Rep. Stud. 12: 8-10. 175
Graham, J.H., D.C. Freeman & J.M. Emleen 1993 Developmental stability: A sensitive indicator of populations under stress. In W.G. Landis, J.S.Hughes & M.A. Lewis. (eds.). pp. 136-158.
Environmental Toxicology and Risk Assessment, ASTM STP 1179, American Society for Testing and Materials, Philadelphia.
Hughes, G.M. 1995 Preliminary morphometric study of the gills of Oreochromis alcalicus grahami from Lake Magadi and a comparison with O. niloticus. J. Fish Biol. 47: 1102-1105.
Jobling, M. 1995 Environmental biology of fishes. Chapman and Hall London. pp. 93-136.
Kisia, S.M. & G.M. Hughes. 1992. Estimation of oxygen diffusing capacity in the gills of different sizes of tilapia, Oreochromis niloticus. J. Zool. (Lond.) 227: 405-415.
Lucky, Z. 1977. Methods For The Diagnosis Of Fish Diseases. Amerind Pub. Co. PVT. Ltd. New Delhi.pp. 74.
Milton, S.W. 1999. Statistical methods in the biological and health sciences. WCB/McGraw-Hill, London. pp. 390-434.
Palmer, A.R. & C. Strobeck. 1986. Fluctuating asymme try: Measurements, Analysis, Patterns. Ann. Rev. Ecol. Syst. 17: 391-421.
Sokal, R.R. & F.J. Rohlf 1987. Introduction to Biostatistics. W.H. Freeman, N.Y. pp. 49-120.
Sowunmi, A.A. 2004. Incidence of gill deformities and asymmetry in small fish population from Asejire reservoir, South-west Nigeria. West Afri. J. Appl. Ecol. (in press).
Van Valen, L. 1962. A study of fluctuating asymmetry. Evolution 16: 125-142.
Zacharov, V.A. & A.V. Yablokov. 1990. Skull asymmetry in Baltic Grey Seal: Effects of environmental pollu-tion. Ambio 19(5): 266-269
Comments
This work is licensed under a Creative Commons Attribution 4.0 International License.
Copyright (c) 2004 Revista de Biología Tropical