Abstract: The activities of alkaline phosphatase and Ca2+ATPase in mud crab (Scylla serrata) collected from a soft-shell crab farm in Chantaburi Province, Thailand, in several stages of molting cycle were observed. The results showed that the activity of alkaline phosphatase in gill after molting was highly significant (p
Abstract: The efficiency of chitosan beads processed from 4
marine animal shells; white leg shrimp (Litopenaeus vannamei), mud
crab (Scylla sp.), horseshoe crab (Carcinoscorpius rotundicauda),
and cuttlefish bone (Sepia sp.), for the adsorption experiments of
ammonia and formaldehyde were investigated. The porosities of
chitosan from the shells looked like beads were distinctly examined
under SEM. The original pores of those shells on the surface areas
compose of evenly fine pores. The shell beads of cuttlefish bone and
horseshoe crab show the larger probably even porosity, while on
those white leg shrimp and mud crab contain various large and fine
pores. The best adsorption at pH 9 in 18 mg/l ammonia at 2 hours
yield on cuttlefish bone, horseshoe crab, mud crab and white leg
shrimp with the average percent of 59.12, 51.45, 45.66 and 43.52,
respectively. Within 30 minutes the formaldehyde absorbers (at pH 5
in 8 μg/ml) revealed 46.27, 26.56, and 18.04 percent capacities in
cuttlefish bone, mud crab and white leg shrimp beads; while 22.44
percent in the horseshoe crab at pH 7. The adsorption capacities and
the amounts of beads showed a positive correlation. The adsorption
capacity relationship between pH and the gas concentrations were
affected by these qualities of chitosan beads.