Proximate Composition and Mineral Contents of Edible Part of Four Species of Shellfishes from the Calabar River, Nigeria

Aims: To evaluate the proximate composition and mineral contents of edible part of four species of shellfishes (Callinectes amnicola, Thais coronata, Tympanotonus fuscatus and Egeria radiata) from the Calabar River, Nigeria.

Place and Duration of Study: Institute of Oceanography, University of Calabar, Nigeria, between October 2016 and May 2017.

Methodology: The proximate composition was analyzed following standard methods recommended by AOAC, while mineral contents were determined using Atomic Absorption Spectrophotometric (AAS) method.

Results: Protein and ash contents were highest in E. radiata (32.10 ± 0.06% and 3.80 ± 0.01%) and least in T. coronata (14.88 ± 0.01% and 2.57 ± 0.02%). Fat, fibre and moisture contents were highest in T. coronata (1.50 ± 0.01%, 0.06 ± 0.01% and 76.35 ±0.01%) and least in T. fuscatus (1.18 ± 0.01%), E. radiata (0.04 ± 0.01% and 61.20 ± 0.11%). Nitrogen-free extract was highest in C. amnicola (6.42 ± 0.25%) and least in E. radiata (1.50 ± 0.10%). Sodium content was highest in C. amnicola (108.34 ± 0.08 mg/100 g) and least in T. fuscatus (16.33 ± 0.01 mg/100 g). Calcium content was highest in T. coronata (188.42 ± 0.09 mg/100 g) and least in T. fuscatus (49.86 ± 0.01 mg/100 g). Copper, iron and manganese contents were highest in T.coronata (10.03 ± 0.02 mg/100 g, 14.83 ± 0.01 mg/100 g and 1.65 ± 0.01 mg/100 g) and least in C. amnicola (0.49 ± 0.01 mg/100 g), E. radiata (8.76 ± 0.01 mg/100 g) and T. fuscatus (0.21 ± 0.01 mg/100 g). All proximate composition and mineral contents except fibre content were significantly different (P < 0.05) among the four species.

Conclusion: The nutritional values of the four species of shellfishes studied are suitable for human consumption, and the species could have potential alternative for animal feed industries. Therefore, aquaculture activities related to shellfishes should be encouraged to reduce pressure and total dependence on wild stock.