ABSTRACT
The effect of salinity on the survival and growth of Callinectes amnicola (De Rocheburne) from the Lagos Lagoon, Nigeria was monitored in the laboratory for 22 weeks. The crabs were euryhaline and tolerated a salinity range of 5 to 25‰ and had 90% survival at 15 and 20‰. The highest gain in weight (173.0%) and carapace width (56.1%) was obtained at salinity of 15‰. The highest specific growth rate (1.98) was obtained at 15‰, while the lowest specific growth rate (-0.28) was recorded at 35‰. The condition factor of the crabs showed a fairly consistent pattern at the different salinity levels with values ranging from 5.7 to 7.3. Complete moulting was obtained at salinity of 15‰ in the 12th week of the experiment. The crab with carapace width of 6.8cm increased to 8.1cm (19.1%) after moulting.
ABSTRACT
Annelids collected from eight stations in the western part of Lagos Lagoon between May, 1996 and February, 1998 were reported. Rainfall, salinity and sediment type influenced distribution of annelids, which were either dry season species, wet season species or euryhaline species. A total of fifty-five species were collected, thirty-one not recorded in earlier studies. Pollution indicators, Polydora sp., Capitella capitata, Nereis sp. and Tubifex sp. were collected in both dry and wet seasons.