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A Checklist of Planktonic Algae off Lagos Coast - Jsrd.org

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80 D. I. Nwankwo. andl.C. Onyema<br />

DISCUSSION<br />

From the study there were comparatively fewer numbers <strong>of</strong> species for this study viz a viz other<br />

seasonal microalgal investigations in the coastal waters <strong>of</strong> Nigeria (Nwankwo, 1988b; Nwankwo et al.,<br />

2003, Onyema et al., 2003). Comparatively, higher abundance and diversity <strong>of</strong> planktonic algal species<br />

was recorded for the dry season (November ‐ April) than in the wet season (May ‐October). For<br />

instance species <strong>of</strong>Coscinodiscus, Chaetocerus, Biddulphia, Ditylum and Ceratium occurred more<br />

frequently in the dry season. A good number <strong>of</strong> the species encountered for this study have been<br />

recorded in marine situations elsewhere (Subramanyan, 1946, Newell and Newell, 1966; Wimmpenny,<br />

1966).<br />

Furthermore, the occurrence <strong>of</strong> din<strong>of</strong>lagellates species such as Ceratium furca, Ceratium fusus,<br />

Ceratium tripos and diatoms such as Chaetoceros convolutus, Cerataulina bergonii and<br />

Coscinodiscus centralis among other diatoms have also been reported to impose anoxia, clogging and<br />

damage <strong>of</strong> fish gills under bloom conditions in the same region (Nwankwo et al., 2003 a,b).<br />

The occurrence <strong>of</strong> the cyanobacteria Trichodesmium thiebautii was observed only in warm,<br />

stratified, relatively nutrient poor waters in the dry season. Nwankwo et al., (2003b) have reported that<br />

Trichodesmium thiebautii blooms in the coastal waters <strong>of</strong> south‐western Nigeria and clogging <strong>of</strong> fishing<br />

nets in bloom conditions have also been reported in the same region for this cyanobacterium<br />

Species <strong>of</strong> Oscillatoria and Phormidium encountered during the study are likely immigrant forms from<br />

land brought in with floodwaters during the rains.<br />

REFERENCES.<br />

Chinda, A.C and Pudo, J. (1991). "A preliminary checklist <strong>of</strong> algae found in plankton <strong>of</strong> Bonny<br />

River in Niger Delta, Nigeria". Fragmflor. Geobot.36 (1): 112‐126.<br />

Desikachary, T.V. (1959). Cyanophyta. Indian Council <strong>of</strong> Agric. Research, New Delhi. 686pp. Egb<strong>org</strong>e,<br />

A.M.B. (1973). "A preliminary check list <strong>of</strong> the phytoplankton <strong>of</strong> the Oshun river,<br />

Nigeria". Freshwater Biol. 4: 177 ‐ 191. Foged, N. (1966). "Freshwater diatoms from Ghana".<br />

Biologiske Skrifter Det Kongelige Dansfe<br />

Videnskabernes Selskab. 15(1). 160pp F.A.O. (1969). Fisheries Survey in the Western and Mid‐<br />

Western Regions <strong>of</strong> Nigeria. FAO/Sf:<br />

74/NIR 6. 142pp. Fox, M. (1957). "A first list <strong>of</strong> marine algae from Nigeria". Jour. Linn. Soc.<br />

London. LV (365):<br />

615‐631. Hendey, N.I. (1958). "Marine diatoms from West African Ports". Journal <strong>of</strong> Royal<br />

Microscopic,<br />

Society. 77: 28‐88.

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