Variations of manganese in the eggs of the Norway lobster, Nephrops norvegicus (L.).
The Norway lobster, Nephrops norvegicus, lives on sediments rich in manganese (Mn). Temporal fluctuations of Mn in the eggs of N. norvegicus was investigated, both in the field and in laboratory experiments. Female gonads and external eggs of different developmental stages were measured for Mn. The Mn concentration during oocyte maturation and throughout most of the embryogenesis (after fertilisation) remained stable around 5 µg Mn g(-1) dry wt. egg. At the end of the embryonic development (about 6 months after fertilisation) the Mn concentration of the egg started to increase and had at the time of hatching reached concentrations of 120 µg Mn g(-1) dry wt. egg. The egg shell was at this stage highly permeable and Mn was taken up by the embryo and egg shell in equal amounts.
Eriksson
SP
Göteborg University, Department of Marine Ecology, Kristineberg Marine Research Station, S-450 34, Fiskebäckskil, Sweden