Technological aspects of processing of edible mussels, clams and crabs. Pt. 1. Spoilage during ice storage

Rate and pattern of spoilage of some of the economically important edible species of shell fishes Mytilus edulis (Mussel), Villorita cornucopia (Clam), Neptunus pelagicus (Crab) and Scylla serrata (Crab) have been discussed in this communication. Chemical indices used for objective evaluation of quality were water extractable nitrogen (WEN), non-protein nitrogen (NPN), free α-amino nitrogen (α - NH2 -N), glycogen, lactic acid and inorganic phosphorus in addition to the subjective tests. No significant difference in the spoilage pattern of the species during ice storage was observed and these species could be preserved in ice in organoleptic acceptable condition up to 8 days, 9 days, 8 days and 11 days respectively.

Growth of Skipjack Katsuwonus pelamis from Mozambique

Growth of skipjack, Katsuwonus pelamis in Mozambican waters was studied, using fork length data collected in 1983-1985, during an experimental pole-and-line/live-bait fishing program. Tentative estimates of growth parameters are FL∞=80 cm, K=0.6 yearˉ¹. Some evidence for seasonal growth is presented, along with a discussion of the limitations of the data set used in the investigation.

Nutrient salts in the United Arab Emirates waters (the Arabian Gulf and the Gulf of Oman)

This paper deals with the levels and distributions of nutrient salts in the United Arab Emirates waters. Water samples were collected bimonthly during 1994-1995 from the marine environment of the United Arab Emirates, which extends more than 800km along the Arabian Gulf and the Gulf of Oman. Concentrations of ammonium, nitrite, nitrate, phosphate, silicate, as well as total concentrations of total dissolved nitrogen, phosphorus, and silicon in the area were scattered in the ranges: (ND-6.32; mean: 0.84 µg-at N/l), ND-3.02; mean: 0.42 µg-at N/l), (ND-10.88; mean: 1.18 µg-at N/1), (ND-4.22; mean: 0.62 µg-at P/l), (1.14-28.80; mean: 6.52 µg-at Si/l), (1.52-39.58; mean: 12.28 µg-at N/l), (0.40-4.98; mean: 1.07 µg-at P/l), and (2.77-44.74; mean: 13.02 Si/l) respectively. Of inorganic nitrogen species, ammonium was the highest in the Arabian Gulf waters and nitrate was the highest at the Gulf of Oman. The dissolved inorganic nitrogen total species, phosphate and silicate amounted to 16.4, 47.6, 56.5% respectively, of the concentrations of nitrogen, phosphorus and silicon in the Arabian Gulf and 22.6, 64.4, 44.9% respectively, in the Gulf of Oman, indicating that more than 80% of nitrogen was present in organic forms. Distributions of nutrient in the two regions were higher in the summer season and lower in the winter season due to the oxidation of organic materials. Regional distributions revealed higher values for nitrite (1.3 times), nitrate (2.8 times), phosphate (2.2 times), total dissolved nitrogen (1.3 times), total dissolved phosphorus (1.6 times), and total dissolved silicon (1.3 times) in the Gulf of Oman compared to the Arabian Gulf, indicating more oligotrophic conditions at the Arabian Gulf Whereas no distinct patterns of distribution were observed in the Arabian Gulf waters, an increase in the seaward direction was measured at the Gulf of Oman. Vertical distributions indicated a general increase with depth in the two regions. The mean ratios for total concentrations of phosphorus, nitrogen, and silicon in the Arabian Gulf (1: 11.6: 12.6) and the Gulf of Oman (1: 10.1: 11.8) were lower than the Redfield ratio.