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Vol. 51 No. 5, 2012
Spatiotemporal Variations in the Abundance, Biomass, Fecundity, and Production of Oithona brevicornis (Copepoda: Cyclopoida) in a West African Tropical Coastal Lagoon (Grand-Lahou, Côte d’Ivoire)
Raphael N’doua Etilé1,2,*, Maryse N’guessan Aka2, Aka Marcel Kouassi2, Marc Pagano3, and Valentin N’douba1
1Laboratoire d’Hydrobiologie, UFR Biosciences, Université de Cocody-Abidjan 22 BP582, Abidjan, Côte d’Ivoire
2Centre de Recherches Océanologiques (CRO), BPV 18, Abidjan, Côte d’Ivoire
3Mediterranean Institute of Oceanography, MIO, IRD, UMR 235, 13288 Marseille Cedex 09, France
Raphael N’doua Etilé, Maryse N’guessan Aka, Aka Marcel Kouassi, Marc Pagano, and Valentin N’douba (2012) Oithona brevicornis
is a very important zooplankton species in coastal and estuarine
aquatic ecosystems of West Africa and was recorded in very high
abundances in coastal lagoons of Côte d’Ivoire. To better
understand the functional role of this key species, spatio-seasonal
variations in O. brevicornis abundance, biomass, fecundity, and
production were investigated at 21 stations in Grand-Lahou Lagoon
during an annual cycle from Jan. to Dec. 2004. The abundance and
biomass showed more or less important spatiotemporal variations.
Two peaks were recorded for the mean spatial values in Feb.-Mar. and
Sept. During the long (LDS) and short dry seasons (SDS), all
developmental stages showed their weakest density and biomass in the
channel zone and near the mouth of the Boubo River. During the
long (LRS) and short rainy seasons (SRS), O. brevicornis
almost disappeared or showed very low abundances (< 1 individual/L)
in the northern part and near the channel. Spatiotemporal
variations in O. brevicornis
fecundity and production showed no particular pattern during the dry
seasons (LDS and SDS), while during the rainy seasons (LRS and SRS),
very low fecundity and production values were recorded at stations
influenced by river inputs. Correlation analyses showed that
temperature and salinity were the main variables explaining these
spatio-seasonal variations.
Key words: Oithona brevicornis, Biomass, Egg production, Tropical lagoon, West Africa.
*Correspondence: E-mail:nouda_et@yahoo.fr
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