Assessment of Biochemical Compositions and Mineral Contents of Carapace of Some Important Commercially Crustaceans and Mollusks Organisms from Egyptian and Saudi Arabia Coasts as a New Animal Feed

Abstract

Carapace of commercial crustaceans species (mantis shrimps ; Erugosquilla. massavensis, the penaeid shrimps ; Peaneus. semisulcatus ; Metapenaeus monoceros and blue crab; Portunus pelagicus ) and commercial mollusks (cuttlefish ; Sepia and bivalve mollusks; Cardium edule) were chosen for this study to assess carbohydrates, protein, lipids and to estimate their Fe, Cu, Co, Hg, Pb and Cd contents, as an attempt to use the carapace of marine invertebrates organisms as a cheap protein animal feed. Additionally, to investigate the interrelation between the exoskeleton of these marine animals and water pollution. In the terms of nutritive quality, the present results show that the carapace of both sex of E. massavensis was the richest nutritive source compared to that of all studied samples. Furthermore, the recorded data indicate that the exoskeleton of all studied crustaceans organisms and the internal shell of cephalopod mollusks had higher nutritive contents than the exoskeleton of bivalve mollusks. Concerning with heavy metal bioaccumulation, the present study show that the carapace in both sexes of E. massavensis accumulated higher percentages of the determined metals than those of other studied crustaceans species. On the other hand, Sepia spp. exhibited the lowest levels of the studied metals comparable to crustaceans and C. edule species. While, all species of C. edule accumulated the higher concentrations of Fe, Co, Pb and Cd in their shells than those in all studied crustaceans species. In this respect, the values of Metal Pollution Index (MPI) of studied essential elements in all studied species were higher than that of non- essential elements. Moreover, the highest values of essential and non-essential elements were recorded in all E. massavensis and C. edule samples respectively. While, the lowest level was detected in Sepia spp. followed by crab species. This primary work is an attempt to pursue further research in this line and will also be useful in the preparation of value added sea foods; the findings of the current study may help to select the appropriate species for animal feed. Moreover, the present study suggests that the exoskeleton of crustaceans and bivalves mollusks can be used as indicator of water pollution and this suggest their tendency to detoxification mechanism of heavy metals as a mean of protection. This in turn suggests that a close monitoring program is need to ensure the safety of these crustacean and mollusks species as a food source for animals.