The clam Venerupis aurea (Gmelin, 1971) is one of the most commercially important bivalves in Lake Timsah, Suez Canal. Population dynamics for this clam was explored from August 2015 to September 2016 at two clam beds; Taawen site and Etap site of different sediment characters, population densities and fishing exploitation in the lake. The average density of the species at the exploited Taawen site (3,930 ind. m-2) was significantly higher (one way ANOVA, P = 5.15) than at unexploited Etap site (1,141 ind. m-2). Length frequency data were analyzed by FiSAT software for estimation of population parameters to evaluate the status of the stock. Asymptotic length (L8) was similar (36.57 mm) in the two beds. Growth coefficient (K) was higher in Etap site (0.36 yr-1) than in Taawen site (0.28 yr-1). The theoretical lifespan (Tmax) was higher in Taawen site (12.4 years) than in Etap site (9.7 years). Total mortality (Z) was estimated by length-converted catch curve at 0.81 and 0.98 yr-1, fishing mortality (F) at 0.11 and 0.22 yr-1 and natural mortality (M) at 0.70 and 0.76 yr-1 for Taawen site and Etap site, respectively. The estimated value of the exploitation rate (E) was higher in Etap site (0.23) than in Taawen site (0.14). The recruitment pattern was continuous with two major peaks in the two beds and was found to be correlated with the spawning pattern in the species. Recruited juvenile relative to the total population all over the study period was higher in Taawen site (34.50%) than in Etap site (20.47%). Overexploitation can only be mitigated by imposing stringent restrictions in terms of the minimum size for exploitation (12 mm shell length) and closed seasons during the spawning peak (September, December and April).

Egyptian beaches have extended over long distances and it has become necessary to look at how the exploitation of bivalves inhabiting these beaches. Onset of sexual maturity for 7 bivalve species in 4 sites of Egyptian waters was reported. Specimens were collected during summer and winter seasons. A total of 1870 individuals belonging to 4 families were examined under the microscope. The trend of decreasing size at maturity with increasing water temperature was reported. The trend of increasing size at maturity with decreasing latitude was much less clear in this study. The size at 50% maturity (SM50) varied between 9.2 mm SL (for Cerastoderma glaucum in summer) and 16.6 mm SL (for Venerupis aurea in winter), and showed an average value of 12.7 mm SL (± 2.4 S.D.) for 5 commercial clams.

The recruitment pattern of the venerid Venerupis aurea was monitored from August 2004 to September 2005 to investigate the feasibility of collecting natural spat for management or maricultural purposes. Three sites of varying adult densities were chosen in the southern region of Lake Timsah, Suez Canal, Egypt. Recruitment is used, herein, to refer to juveniles of generally less than 9 mm shell length. The separation between juveniles and adults was based on the size at onset of maturity. Recruitment of V. aurea was continuous throughout most of the year and varied significantly among the three sites. Monthly collections yielded an average of 687.1, 239.5, and 115.3 spat m-2 at sites I, II, and III, respectively. Higher abundance of recruits occurred during the period from November 2004 to March 2005. The average density of juveniles for this period (n = 5) was 1508.0, 293.6, and 262.4 ind. m-2 at the three sites, respectively. The data suggest that the survival of recruits is probably influenced by abiotic factors, particularly sediment composition, rather than by biotic factors such as adult-juvenile interactions. The growth in length for juveniles from site I is accompanied by growth in weight (isometric growth). At site II and III, weight increased relatively slower than length indicating negative allometric growth.