Abstract
A total of 100 random samples, of retailed marine fish and shellfish, 25 of each (sardine,mullet,crab,shrimp) were randomly collected from different fish markets at Alexandria province are subjected to sensory , chemical and microbial analysis for safety and quality assessment .All samples examined for odour, color and consistency were apparently normal .The results showed that the mean values of pH for the examined samples of crab , mullet ,sardine and shrimp were 5.93±0.03, 5.9±10.03 , 5.93±0.03 and 5.97±0.03 mg/100g respectively; the mean values of Total volatile nitrogen were 14.10±0.75, 15.67±0.54, 12.80±0.52 and 14.83±0.65mg/100g ,respectively; the mean values of Thiobarbituric acid were 0.20±0.03, 0.17±0.01, 0.12±0.02 and o.22±0.04 mg/100g ,respectively; while, the mean values of Trimethylamine 3.76±0.15 ,4.16±0.16 , 4.23±0.23 and 3.61±0.14 mg/100g,respectively.The results of microbial analysis showed that the mean values of Aerobic mesophilic count were 6.2x106±1.3x106for crab, 2.2x106±0.80x106for mullet , 1.0x106±0.27x106for sardine , 1.9x106±0.36x106 cfu/g for shrimp; the mean values of Psychrophilic bacterial count were 4.4x106±0.8x106for crab, 9.7x105±2.2x105for mullet, 1.1x106±0.51x106for sardine , 3.2x106±0.6x106 cfu/g for shrimp ;the mean values of Hallophilic bacterial count were 3.7x106±0.58x106for crab, 4.1x106±1.6x106for mullet, 7.8x105±2.3x106for sardine, 3.0x106±0.5x106 cfu/g for shrimp; the mean values of Enterobacteriaceae count were 5.2x106±1.2x106 for crab, 8.3x106±3.4x106 for mullet, 5.4x106±2.6x106for sardine,1.2x106±0.2x106 cfu/g for shrimp;the mean values of mould and yeast count were 5.2x106±1.2x106for crab, 8.3x106±3.4x106, for mullet, 5.4x106±2.6x106 for sardine , 1.2x106±0.2x106 cfu/g for shrimp; the incidence of Staphylococcus aureus was 16% for crab, 44%for mullet ,24% sardine and 8% for shrimp; the incidence of Vibrio parahaemolyticus was 24%for crab ,44%for mullet ,28% sardine and 20% for shrimp.This study showed the degree of contamination of crab, mullet ,sardine and shrimp in addition the public health importance of such contaminates has been discussed.

Key words: Fish and shellfish ,sensory evaluation, chemical analysis, microbial analysis.