Cytotoxic and genotoxic responses of the RTgill-W1 fish cells in combination with the yeast oestrogen screen to determine the sediment quality of Lagos lagoon, Nigeria.

Economic advancements in developing countries have seen an increase in urbanisation and industrialisation with a rise in the levels of discharge of effluents and municipal waste into aquatic ecosystems. Unfortunately, aquatic environmental regulations in these countries are often rudimentary and the development of environmental monitoring programmes will help identify ecological risks. As an example, the current study assesses the pollution status of 11 sampling sites in Lagos lagoon, Nigeria.

Effects of dietary calcium on growth and oviposition of the African land snail Limicolaria flammea (Pulmonata: Achatinidae).

In an attempt to elucidate the role of calcium in the life of the edible Achatinid snail, Limicolaria flammea (Miller) I investigated short and long term effects of calcium added to the food. The short term experiments lasted for 18, 30 and 32 weeks respectively, while the long term experiment to determine life time utilization of calcium carbonate lasted for 15 months. In the short term experiments, hatchlings were divided into densities of one, ten and 50 snails.

An ultrastructural study of the seminal vesicle of the hermaphrodite duct of the land snail Limicolaria flammea (Müller) (Pulmonata: Achatinidae).

The seminal vesicle region of the hermaphrodite duct of the edible land snail, Limicolaria flammea (Müller) is described using light and electron microscopy. The lumen is lined with a single layer of epithelial cells surrounded by connective tissues and circularly arranged smooth muscle. Transmission electron microscopy reveals that there are two types of epithelial cells lining the lumen of the seminal vesicle duct.

Reproductive cycle of the mangrove prosobranch, Pachymelania fusca (Gmelin, 1791) var. quadriseriata (Gray) (Gastropoda: Melaniidae) in Lagos, Nigeria.

The reproductive activity of the mangrove prosobranch, Pachymelania fusca was studied monthly in the University of Lagos mangrove swamp, at the edge of the Lagos lagoon. The reproductive cycle was analysed from November 2003 to March 2005 by histological examination and macroscopic features of the gonads. Four gonadal stages are described: recently spawned, unripe, ripe and spawning gonads.

Gross morphology and ultrastructural study of albumen gland of the land snail Archachatina marginata ovum (Pfeiffer) (Pulmonata: Achatinidae).

The gross morphology of the albumen gland of the edible land snail Archachatina marginata ovum (Pfeiffer) was studied by measurement of the shell length of the snails and wet weight of albumen gland of specimens collected from wild. Additionally, the structure of the albumen gland was studied by light and electron microscopy. The gland is large during the breeding season and there is no correlation between its weigh and the shell length of the snail.

Thermal tolerance and evaporative water loss of the mangrove prosobranch Tympanotonus fuscatus var. radula L. (Cerithiacea: Potamididae).

Rate of weight loss and mortality, of the Nigerian periwinkle, Tympanotonus fuscatus var. radula L. were investigated during prolonged exposure to air for one month.