Brief Ecology of Callinectes Amnicola, Parasite Invasion and Physiochemical Influence in Udu River, Warri, Delta State.

Nigeria's rivers, swamps, and mangroves are home to a variety of crabs. These environments support both freshwater and saltwater crabs, which play a significant role in the country’s biodiversity and contribute to the livelihoods of local communities. This study investigates the brief ecology of Nigerian crab species, focusing on Callinectes amnicola in the Udu River, Delta State. Crabs play a crucial role in nutrient recycling and support local economies through the fishing industry. However, their populations face threats from pollution, habitat destruction, overfishing, and parasitic infections. The study assessed the river's physicochemical parameters, identified crab species, and examined parasitic infestations. Water samples were collected from three stations, analyzing total dissolved solids (TDS), conductivity, pH, dissolved oxygen (DO), biological oxygen demand (BOD5), and temperature. Crabs were sampled and dissected for parasitic investigation. Results showed that physicochemical parameters were within safe limits, with TDS ranging from 62.8 to 78.2 ppm, conductivity from 128.4 to 155.1 µS/cm, and pH between 6.1 and 7.0. DO levels were optimal at 6.2 to 7.6 mg/L, while BOD5 values indicated moderate organic pollution. Only Callinectes amnicola was identified, with the highest density at Station 2. Parasitic analysis revealed Monocystis sp., Hysterothylacium sp., and Trichuris sp., with elevated loads in the gills and guts of crabs from Station 2. These findings highlight the stable water quality of the Udu River yet underscore the significant parasitic challenges faced by the crab population. Conclusively, while the river's ecological health appears stable, the presence of parasites poses a threat to crab species. Recommendations include establishing conservation efforts to protect crab habitats, implementing monitoring programs for physicochemical parameters and parasitic infections, and raising public awareness about sustainable fishing practices. By addressing these issues, stakeholders can help safeguard crab populations and their habitats, ensuring the ecological health of Nigeria's freshwater ecosystems.