Morphologic variations of periwinkle and profiles of periwinkle marketers and harvesters in two states in the Niger delta area of Nigeria

Abstract

Periwinkles are invertebrates rich in protein and omega-3 fatty acids. These make them relished delicacies. Three hundred and fifteen (315) individual periwinkles were hand-picked from mangrove swamp river banks and intertidal zones of Twon-Brass in Bayelsa State and Abonnema town of Rivers State. Shell length and the weight of both the meat and shell were taken with Veneer caliper and a sensitive electronic scale balance respectively. Information on the economics of production was gathered from market women and harvesters through the use of structured questionnaires. The present study indentified possible phenotypic differences among periwinkle harvested in Bayelsa and Rivers States base on shell length and meat weight differences. Periwinkle harvested in Rivers is bigger and heavier than those harvested in Bayelsa State. Prediction of meat and total weight of from shell length was done using regression analysis. The study also identified the involvement of the different age groups that form the work-force in the States; showing that there are more young adults and teenagers in the business of harvesting and sales than aged people. There are more men involved in the business than women. There is a decline in size, quantity and availability of periwinkle presently than in the past, a factor that could be attributed to over-harvesting.

Key Words: Bayelsa, Morphology, Niger Delta, Periwinkle, Rivers.