Morphological Observation of Common Pennate Diatoms (Bacillariophyceae)

Common pennate diatoms in two estuaries of Kuching, Sarawak, Malaysia were documented based on samples collected from September 2008 till Febuary 2009. Plankton samples were subjected to acid wash before detailed morphological observations. All specimens were identifi ed to species level under transmission and scanning electron microscopy (TEM & SEM). During the study period, seven genera of pennate diatoms were commonly found in the samples, they are Amphiprora, Surirella, Delphineis, Navicula, Nitzschia, Cylindrotheca and Pleurosigma. Identifi cation of species was based on the raphe systems and poroid arrangement. A total of 16 species was documented with two species of Amphiprora (A. gigantea and A. alata), three species of Surirella (S. fl uminensis, S. fastuosa and S. norvegica), two species of Delphineis (Delphineis and D. kurtzii), one species of Navicula (N. distans), four species of Nitzschia (N. longissima, N. obtusa, N. panduriformis and N. cf. amphibia), one species of Cylindrotheca (Cylindrotheca closterium) and three species of Pleurosigma (P. angulatum, P. spencerii and P. normanii) described. This study represents one of the few studies on marine and brackish diatoms in the Malaysian waters