Commercial aquaculture in Nigeria: a vertically integrated approach in the commercial freshwater farming of tilapia in floating bamboo net-hapas and cages systems

Tilapia once termed "poor man's" fish, still remains as the highly-priced food fish in many developing countries. The good attributes of this fish prompt its use in intensive aquaculture vertically integrated systems (VIS) which embrace broodstock development, hatchery/nursery and growout phase. Based on the series of studies carried out at Kainji Lake Research Institute, in New Bussa, Nigeria using Oreochromis (Tilapia niloticus) in floating bamboo hapas/cages, the recommended intensive modular systems were estimated to be capable of producing 4 million Tilapia fingerlings and 729 tons fish (Market-size) annually. Cost-benefit analysis showed the venture to have high prospects. It is recommended that priority be given to Tilapia cage culture at the national level in order to contribute immensely towards increased fish production

Effects of land use and physicochemical water quality on grass shrimp, Palaemonetes pugio, and its parasitic isopod, Probopyrus pandalicola, in South Carolina, USA tidal creeks

Grass shrimp, Palaemonetes pugio, are a common inhabitant of US East and Gulf coast salt marshes and are a food source for recreationally and economically important fish and crustacean species. Due to the relationship of grass shrimp with their ecosystem, any significant changes in grass shrimp population may have the potential to affect the estuarine system. Land use is a crucial concern in coastal areas where increasing development impacts the surrounding estuaries and salt marshes and has made grass shrimp population studies a logical choice to investigate urbanization effects. Any impact on tidal creeks will be an impact on grass shrimp populations and their associated micro-environment whether predator, prey or parasitic symbiont. Anthropogenic stressors introduced into the grass shrimp ecosystem may even change the intensity of infections from parasitic symbionts. An ectoparasite found on P. pugio is the bopyrid isopod Probopyrus pandalicola. Little is known about factors that may affect the occurrence of this isopod in grass shrimp populations. The goal was to analyze the prevalence of P. pandalicola in grass shrimp in relation to land use classifications, water quality parameters, and grass shrimp population metrics. Eight tidal creeks in coastal South Carolina were sampled monthly over a three year period. The occurrence of P. pandalicola ranged from 1.2% to 5.7%. Analysis indicated that greater percent water and marsh coverage resulted in a higher incidence of bopyrid occurrence. Analysis also indicated that higher bopyrid incidence occurred in creeks with higher salinity, temperature, and pH but lower dissolved oxygen. The land use characteristics found to limit bopyrid incidence were limiting to grass shrimp (definitive host) populations and probably copepod (intermediate host) populations as well.