Abstract.A study was made from January 1988 to March 1989 of the penaid prawns in the Great Bitter Lake and Lake Timsah located in the central part of the Suez Canal.Two species of Red Sea origin were investigated, Metapenaeus stebbingi and Trachypenaeus curvirostris; the former is by far the commoner. Both species displayed seasonal breeding over the period April to October, with peaks in the early and late parts of the season. M. stebbingi had two main cohorts each year. A spring-spawned cohort survived 16 too, and attained modal sizes of 23 mm carapare length (CL) for females and 16 to 17 mm CL for males. The autumn-spawned cohort survived 13 too, and reached modal sizes of 20 mm and 15 mm CL for males and females, respectively. The reasons for the success of M. stebbingi in the Canal lakes, in contrast to other "Lessepsian" penaeids which have flourished in the Mediterranean Sea, have been considered. The main factors are that it is essentially a shallow-water species, with excellent tolerance of salinity variations and adverse environments. However, the Canal lake populations have smaller maximum sizes, and mature earlier, than those in open seas.

No abstract

The serpulid polychaete Spirobranchus tetraceros of Red Sea / Indo-pacific origin, recently has succeeded to establish a foothold in Alexandria Mediterranean waters. Worms were monthly scraped from submerged iron substrates at Abu Kir Bay during the period

A 63-day feeding study was conducted to evaluate the e¡ect of partial substitution (0%, 20%, 40% and 60%) of dietary ¢sh meal (FM) with soybean meal (SBM) on the growth performance and feed utilization of speckled shrimp, Metapenaeus monoceros juveniles. A total of 180 M. monoceros juveniles with an average weight of 0.67 AE 0.18 g were equally distributed over 12 glass aquaria (30 L each, triplicate per treatment). All aquaria were ¢lled with ¢ltered sea water (30^35 %, salinity). Four isonitrogenous (400 g kg À 1 crude protein) and isocaloric (20.5 MJ GE kg À 1 ) test diets were formulated. The control diet contained FM (D 1 ) as the main protein source. In the other diets, FM was partially replaced with 20 (D 2 ), 40% (D 3 ) or 60% (D 4 ) SBM. The results indicate that the diet in which 40% of the FM is replaced by SBM yields similar growth and production, and is as cost e¡ective, as the control diet.Mean values (AE SD) in the same row sharing the same superscript are not signi¢cantly di¡erent (P 0.05). D 1 , 100% FM; D 2 , 20% SBM; D 3 , 40% SBM; D 4 , 60% SBM; FM, ¢sh meal; SBM, soybean meal.Soybean meal for speckled shrimp S H Abdel Rahman et al.Mean values (AE SD) in the same row sharing the same superscript are not signi¢cantly di¡erent (P 0.05). D 1 , 100% FM; D 2 , 20% SBM; D 3 , 40% SBM; D 4 , 60% SBM; FM, ¢sh meal; SBM, soybean meal.Aquaculture Research, 2010, 41, e299^e306 Soybean meal for speckled shrimp S H Abdel Rahman et al. r 2010 The Authors Journal Compilation r 2010 Blackwell Publishing Ltd, Aquaculture Research, 41, e299^e306 e303Mean values (AE SD) in the same row sharing the same superscript are not signi¢cantly di¡erent (P 0.05). Ã $1 55.5 LE.ECR, economical conversion rate; FCR, feed conversion ratio; D 1 , 100% FM; D 2 , 20% SBM; D 3 , 40% SBM; D 4 , 60% SBM; FM, ¢sh meal; SBM, soybean meal.Soybean meal for speckled shrimp S H Abdel Rahman et al.

A quantitative survey of reef community structure was carried out within the Ras Mohammed Marine National Park in the southern Sinai. Ten transects were surveyed to a depth of 40 m around the southern tip of the Ras Mohammed Peninsula. Percentage cover of designated taxa was recorded within 9m 2 quadrats located at 5 m depth intervals. Sedimentation rates were recorded. Different taxa showed clear patterns of distribution related to depth and to site. These are related to variations in slope, water movement, sedimentation, and diving pressure. The implications of the results for the Marine Park management are summarised.