Feeding ecology of the mangrove oyster, Crassostrea gasar (Dautzenberg, 1891) in traditional farming at the coastal zone of Benin, West Africa

Alphonse Adite, Stanislas P. Sonon, Ghelus L. Gbedjissi

Laboratoire de Parasitologie & Ecologie Parasitaire, Département de Zoologie, Faculté des Sciences et Techniques, Université d’Abomey-Calavi, Cotonou, Bénin.
PRECOB, Unité de Recherches sur les Zones Humides (URZH), Département de Zoologie, Faculté des Sciences et Techniques, Université d’Abomey-Calavi, Cotonou, Bénin.

DOI: 10.4236/ns.2013.512151                

Abstract

Wild collection management and farming of the mangrove oyster (Crassostrea gasar) occurring widely at the Benin (West Africa) coastal zone require knowledge on the feeding ecology to explore energy sources and nutritional needs. Six hundred thirty (630) individuals of C. gasar have been sampled in the rearing site at the Benin coastal lagoon to investigate on the trophic ecology of this cultivated bivalve. The diet analysis revealed that C. gasar is a filter-feeder foraging mainly on phytoplankton (72.70%) and substrate particles (22.95%). This trophic specialization results from anatomical structure, mainly the presence of gills which facilitate the filtering of number of plankton taxa. Dominant phytoplanktons ingested comprised of Diatomophycea (33.52%), Chlorophycae (17.19%), Scenedesmacae (13.80%), Dictyosphaeriacae (3.79%), and Pleurococcacae (2.75%). Eight genuses of phytoplankton, Polycystis, Coelosphaerium, Protococcus, Botryoccocus, Crucigenia, Melosira, Cyclotella, and Gyrosigma dominated the diet of C. gasar with aggreated volumetric proportions reaching 69.06% of the diet. Higher occurrences were recorded mainly for Melosira occurring in 263 (41.75%) stomachs, substrate particles in 211 (33.49%), and Polycystis in 151 (23.97%). C. gasar exhibited a high niche breadths varying from 4.54 to 5.78, suggesting that this bivalve consumed a high variety of food items, thus exhibiting a degree of trophic plasticity. Diet overlaps (?_jk) among different size classes were high and varied from 0.71 to 0.98, indicating an ontogenetic diet shift pattern in C. gasar. Probably, to adapt to the benthic-muddy environment and to increase survival, C. gasar has evolved a specialized feeding mechanism and strategy to retrieve only needed nutrients for growth and to reject awful and nondigestible foods. Also, at the oyster rearing grounds, there is an evidence of shift in the food web structure leading to an increase of the biological productivity at the coastal zone. The output from this study is a valuable documentation for the sustainable development of oyster aquaculture, wild stock management and conservation. However, further scientific knowledge on nutritional needs, phytoplankton toxicity and habitat degradation, and improvement of farming techniques are required for an integrated oyster management.

Keywords

Conservation; Crassostrea; Diet Overlaps; Farming; Filter-Feeder; Food Web; Foraging Strategy; Phytoplankton

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	South Australian Oyster Research Council (2010) The best oysters are pure: Nutritional facts, vitamins and mineral. http://www.coffinbayoysters.com.au
[2]	FAO (1982) Coastal aquaculture development perspectives in Africa and case studies from other regions. CIFA Technical Paper, CIFA/CPCA/T9.
[3]	Abiogba, O.E. and Henadou J. (2006) Contribution à l’étude des huitres exploitées au lac Nokoué: Etat des lieux. Mémoire pour l’obtention du Diplome d’Etude Agricole Tropicale, LAMS, Sékou.
[4]	Adite, A., Abou, Y., Sossoukpê, E. and Fiogbe, D.E. (2013) The oyster farming in the coastal ecosystem of Southern Benin (West Africa): Environment, growth and contribution to sustainable coastal fisheries management. International Journal of Development Research, 3, 87-94.
[5]	FAO (1976) Conférence technique de la FAO sur l’aquaculture, Kyoto, Japon, 26 Mai 2 Juin 1976. Rapport FAO Pêches, No. 188.
[6]	NOAA (2013) PMEL carbon program. http://www.pmel.noaa.gov/co2/story/What+is+Ocean+Acidification%3F
[7]	Global Biodiversity Information Facility (2013) GBIF backbone taxonomy. http://www.gbif.org/species/2286068
[8]	Miossec, L., Le Deuff, L. R.-M. and Goulletquer, P. (2009) Alien species alert: Crassostrea gigas (Pacific oyster). ICES Cooperative Research Report, No. 299, Copenhagen.
[9]	Abgrall, M.-J., Bastien-Daigle, S., Miron, G. and Ouellette, M. (2010) Potential interactions between populations of Softshell Clams (Mya arenaria) and Eastern Oysters (Crassostrea virginica) in temperate estuaries, a literature review. Canadian Technical Report of Fisheries and Aquatic Sciences, No. 2892.
[10]	PAZH (1999) Rapport sur le programme d’aménagement des Zones Humides. PAZH-MDR, Cotonou.
[11]	Adite, A., Kinkpe, R. K., Sossa, G. N., and Viaho, C. C. (2005) Données préliminaires sur l’ostréiculture traditionnelle à la lagune cotière du Bénin (West-Africa). Technical Report, PRECOB/FAST/UAC, Abomey-Calavi.
[12]	GCLME (2006) Guinea current large marine ecosystem report. GEF/UNIDO/UNDP/UNEP/US-NOAA, Cotonou.
[13]	Diedhiou, M. (2008) Contribution à l’étude de la qualité bactériologique des huitres fraiches dans l’aire marine protégée du petit Kassa (Casamance). Mémoire de DESS Pêche—Aquaculture, Université Cheikh Anta Diop, Dakar.
[14]	Quayle, D.B. (1980) Les huitres sous les tropiques: Culture et Méthode. I.D.R.C., Ottawa.
[15]	PADPPA (2010) Elaboration de la politique nationale des pêches et de l’aquaculture. Rapport final, PADPPA, Cotonou.
[16]	Morton, J.E. (1958) Mollusks: An introduction to their form and functions. Harper and Brothers Editor, New York.
[17]	Aron, M. and Grasse, P.P. (1962) Biologie animale. Edition Masson et Compagnie.
[18]	Mallet, N. (2005) Ecologie alimentaire de l’huitre Crassostrea gigas: Dynamiques des compositions isotopiques naturelles. Thèse de Doctorat, Université de La Rochelle.
[19]	Boehs, G., Lenz, T.M. and Villalba, A. (2009) Xenomas in Crassostrea rhizophorae (Ostreidae) from Camamu Bay, Bahia, Brazil. Brazilian Journal of Biology, 69, 457-458. http://dx.doi.org/10.1590/S1519-69842009000200032
[20]	Akoegninou, A., Oyede, L.M. and Toffi, M. (1993) La mangrove du Benin: Environnement physique, végétation, et essais de gestion. Document technique No 2, FAST-UNB, Abomey-Calavi.
[21]	Needham, G.J. and Needham, P.R. (1962) A guide to the study of fresh-water biology. Holden Day, San Francisco, California.
[22]	Winemiller, K.O. (1989) Ontogenetic diet shifts and resource partitioning among piscivorous fishes in the Venezuelan llanos. Environmental Biology of Fishes, 26, 177199. http://dx.doi.org/10.1007/BF00004815
[23]	Simpson, E.H. (1949) Measurement of diversity. Nature, 163, 688. http://dx.doi.org/10.1038/163688a0
[24]	Krebs, C.J. (1989) Ecological Methodology. Harper & Row Publisher, New York.
[25]	Morgan, G.A. Grieggo, O.V. and Gloeckner, G.W. (2001) SPSS for windows: An introduction to use and interpretation in research. Lawrence Erlbaum Associates, Publishers, Mahwah, New Jersey.
[26]	Pianka, E.R. (1994) Evolutionary ecology. 5th Edition, Harper Collins College Publishers, New York.
[27]	Winemiller, K.O. and Kelso-Winemiller, L.C. (2003) Food habits of tilapiine cichlids of the Upper Zambezi River and floodplains during the descending phase of the hydrological cycle. Journal of Fish Biology, 63, 120-128. http://dx.doi.org/10.1046/j.1095-8649.2003.00134.x
[28]	Adite, A. (2007) Ecologie de Heterotis niloticus (Osteoglossiforme: Osteoglossidae) du Système fluvio-lacustre rivière So-lac Hlan (Sud-Bénin): Conservation et Intérêt pour l’aquaculture. Ph.D. Dissertation, Faculté des Scienes et Techniques, Université d’Abomey-Calavi, AbomeyCalavi,
[29]	Nunoo, F.K.E., Sossoukpe, E., Adite, A. and Fiogbe, D.E. (2013) Foods habits of two species of Pseudotolithus (scianidae) off (West Africa) near shore waters and implications for management. International Journal of Fisheries and Aquaculture, 5, 142-151.
[30]	Jimoh, A.A., Clarke, E.O., Whenu, O.O. and Adeoye, H.B. (2011) Foods and feeding habits of the African river prawn (Macrobrachim vollenhovenii, Herklots, 1857) in the Epe Lagoon, southwest Nigeria. International Journal of Fisheries and Aquaculture, 3, 10-15.
[31]	Newell, R.I.E. and Jordan, S.J. (1983) Preferential ingestion of organic material by the American oyster Crassostrea virginica. Marine Ecological Progress Series, 13, 47-53. http://dx.doi.org/10.3354/meps013047
[32]	Newell, R.I.E. and Langdon, C.J. (1996) Mechanisms and physiology of larval and adult feeding. In: Kennedy, V.S., Newell, R.I.E. and Eble, A.F., Eds., The Eastern Oyster Crassostrea virginica, Maryland Sea Grant College, College Park, Maryland, 185-229.
[33]	Jordan, S.J. (1987) Sedimentation and remineralization associated with biodeposition by the American oyster Crassostrea virginica (Gmelin). Ph.D. Thesis, University of Maryland, Maryland.
[34]	Zimmer-Faust, R.K. and Tamburri, M.N. (1994) Chemical identity and ecological implications of a waterborne, larval settlement cue. Limnology and Oceanography, 39, 1075-1087. http://dx.doi.org/10.4319/lo.1994.39.5.1075
[35]	Adite, A., Winemiller, K.O. and Fiogbe, D.E. (2005) Ontogenetic, seasonal, and spatial variation in the diet of Heterotis niloticus (Osteoglossiformes; Osteoglossidae) in the So River-Lac Hlan system, Benin, West Africa. Environmental Biology of Fishes, 3, 367-378. http://dx.doi.org/10.1007/s10641-004-5563-9
[36]	Adriaens, D., Aerts, P. and Verraes, W. (2001) Ontogenetic shift in mouth opening mechanisms in a catfish (Clariidae, Siluriformes): A response to increasing functional demands. Journal of Morphology, 247, 197-216. http://dx.doi.org/10.1002/1097-4687(200103)247:3<197::AID-JMOR1012>3.0.CO;2-S
[37]	Claessen, D., Van Oss, C., De Roos, A.M. and Persson, L. (2002) The impact of size-dependent predation on population dynamics and individual life history. Ecology, 83, 1660-1675. http://dx.doi.org/10.1890/0012-9658(2002)083[1660:TIOSDP]2.0.CO;2
[38]	Koen Alonso, M., Crespo, E.A., Garcia, N.A., Pedraza, S.N., Mariotti, P.A. and Mora, N.J. (2002) Fishery and ontogenetic driven changes in the diets of the spiny dogfish, Squalus acanthias, in Patagonian waters, Argentina. Environmental Biology of Fishes, 63, 193-202. http://dx.doi.org/10.1023/A:1014229432375
[39]	Steingrimsson, S.O. and Gislason, G.M. (2002) Body size, diet and growth of landlocked Brown Trout, Salmon trutta, in the subarctic River Laxa, North-East Iceland. Environmental Biology of Fishes, 63, 417-426. http://dx.doi.org/10.1023/A:1014976612970
[40]	Barbarino Duque, A. and Winemiller, K.O. (2003) Dietary segregation among large catfishes of the Apure and Arauca Rivers, Venezuela. Journal of Fish Biology, 63, 410-427. http://dx.doi.org/10.1046/j.1095-8649.2003.00163.x
[41]	Garcia-Berthou, E. (1999) Food of introduced mosquitofish: Ontogenetics diet shift and prey selection. Journal of Fish Biology, 55, 135-147. http://dx.doi.org/10.1111/j.1095-8649.1999.tb00663.x
[42]	Garcia-Berthou, E. and Moreno-Amich, R. (2000) Food of introduced pumpkinseed sunfish: Ontogenetic diet shift and seasonal variation. Journal of Fish Biology, 57, 29-40. http://dx.doi.org/10.1111/j.1095-8649.2000.tb00773.x
[43]	Bowen, S.H. and Allanson, B.R. (1982) Behavioral and trophic plasticity of juvenile Tilapia mossambica in utilization of the unstable littoral habitat. Environmental Biology of Fishes, 7, 357-362. http://dx.doi.org/10.1007/BF00005570
[44]	Steward, K.D. (2005) The American oyster. Underwater world 14, Fisheries and Oceans, Canada.
[45]	Shumway, S. (1996) Natural environmental factors. In: Kennedy, V.S., Newell, R.I.E. and Eble, A.F., Eds., The Eastern Oyster Crassostrea virginica. Maryland Sea Grant College, College Park, 467-513.
[46]	Thompson, R.J., Newell, R.I.E., Kennedy, V.S. and Mann, R. (1996) Reproductive processes and early development. In: Kennedy, V.S., Newell, R.I.E. and Eble, A.F., Eds., The Eastern Oyster Crassostrea virginica, Maryland Sea Grant College, College Park, 335-370.
[47]	Wildish, D.J. and Saulnier, A.M. (1993) Hydrodynamic control of filtration in the giant scallop. Journal of Experimental Marine Biology and Ecology, 174, 65-82. http://dx.doi.org/10.1016/0022-0981(93)90251-I
[48]	Wildish, D. and Kristmanson, D. (1997) Mechanisms of seston capture and benthic populations and flow. In: Wildish, D. and Kristmanson, D., Eds., Benthic Suspension Feeders and Flow, Cambridge University Press, Cambridge, 270-312.
[49]	Kennedy, V.S., Newell, R.I.E. and Eble, A.F. (1996) The eastern oyster Crassostrea virginica, Maryland Sea Grant College, College Park.
[50]	Baldwin, B. S. and Newell, R.I.E. (1991) Omnivorous feeding by plantotrophic larvae of the Eastern Oyster Crassostrea virginica. Marine Ecological Progress Series, 78, 285-301.
[51]	Baldwin, B.S. (1995) Selective particles ingestion by oyster larvae (Crassostrea virginica) feeding on natural seston and cultured algae. Marine Biology, 123, 95-107. http://dx.doi.org/10.1007/BF00350328
[52]	Newell, C.R. (1979) Food Resources and Energy Partitioning. In: Newell, C.R., Ed., Biology of intertidal animals, Marine Ecological Surveys Ltd., Faversham, 331389.
[53]	Haven, D. and Morales-Alamo, R. (1966) Aspects of biodeposition by oysters and other invertebrate filter feeders. Limnology and Oceanography, 11, 487-498. http://dx.doi.org/10.4319/lo.1966.11.4.0487
[54]	White, M.E. and Wilson, E.A. (1996) Predators, pests, and competitors. In: Kennedy, V.S., Newell, R.I.E. and Eble, A.F., Eds., The Eastern Oyster Crassostrea virginica, Maryland Sea Grant College, College Park, 559-579.
[55]	Milewski, I. and Chapman, S. (2002) Oysters in New Brunswick: More than a harvestable resource. Conservation Council of New Brunswick, Fredericton, NB.