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Anadara granosa is a bivalve blood cockle occurring abundantly in tropical estuarine intertidal sediments. The accumulation of Cd, Zn and Fe and their partitioning at the sub-cellular level in the cytosol has been investigated in the gills, digestive gland, body and foot of A. granosa from seven estuaries in the Gulf of Thailand. Cadmium and Zn were bioaccumulated predominantly in the gills with smaller concentrations distributed equally throughout the other tissues. Iron was present at relatively low concentrations in gills but was higher, and more evenly distributed, in the digestive gland, body and foot. The concentrations of metallothionein-like protein (MTLP) were found to be in the range 1–11 mg g−1 (dry weight) with the highest values being in the digestive gland at all sites. Partitioning of the metals in the cytosols between low molecular weight (LMW) compounds, MTLP and high molecular weight compounds (HMW) indicated that 16–39% of total Cd, 6.5–15% of total Fe and

A study on the reproductive cycle of the blood cockle Anadara granosa (Bivalvia: Arcidae) was conducted at three different areas in the northern region of the Strait of Malacca. A total of 1,920 samples of adult A. granosa (38–71 mm length) were collected from June 2009 until September 2010. Qualitative techniques (gonadal microscopic fresh smear test and histology analysis) as well as quantitative techniques (analysis of condition index and gonadal index) were used to predict monthly gonadal development stages of A. granosa. The gonadal index of A. granosa from Banda Aceh (Indonesia) (r = 0.469, P > 0.05) and Pulau Pinang (Malaysia) (r = 0.123, P > 0.05) did not show any correlation to their condition index, whereas the gonadal index of A. granosa from Lhokseumawe (Indonesia) (r = 0.609, P < 0.05) showed moderate positive correlation to the condition index. During the 16 month sampling period, four reproductive cycles were observed: each from three to six months. The process of releasing gametes is termed dribble spawning, and is the same in all populations. The principle component analysis (PCA) indicated that A. granosa reproduction was affected by interaction between internal physiological factors and indigenous environmental factors. In all sampling areas, phytoplankton density played a key role in the reproductive cycle in A. granosa. Information on the reproductive biology of this species is essential for species management and to improve the sustainability practices of the fisheries industry. These findings will provide basic information on the biology of the blood cockle A. granosa for stock management in the region.

The ark shell Anadara granosa is a species peculiar to the Ariake Sound. To determine why distribution of A. granosa in Japan is largely confined to this area, we examined feeding and growth of A. granosa as functions of environmental and biological variables. The results were compared with those of another ark shell Scapharca subcrenata, which is ubiquitous in Japan. Feeding experiments indicated that A. granosa is eurythermal and euryhaline, as is S. subcrenata, but is adapted to temperature slightly higher than S. subcrenata. Weight-specific clearance rate (CR) of A. granosa as a function of soft-body dry-weight (w) followed the power function of w (CR=2.7×w−0.37), with coefficient and exponent very close to those for S. subcrenata. Growth rate of A. granosa increased linearly with daily ration, similar to S. subcrenata. Thus, feeding and growth characteristics of A. granosa were comparable to those of S. subcrenata and no ‘peculiarities’ of the former were detected. Therefore, the factors that make A. granosa a species restricted to the sound are probably not directly related to feeding or growth characteristics.

Polonium-210 has been measured in the soft parts of Anadara granosa purchased at Kuala Selangor, West Coast of Malaysia in August 2001, April 2002 and September 2002. It is shown that 210Po is non-uniformly distributed within cockles of various sizes (i.e., 2.5, 3.0, 3.5 and 4.0 cm of shell length) and the concentration of 210Po in the soft parts of cockle was significantly different (p

Neutron Activation Analysis (NAA) and Inductively Coupled Plasma (ICP) spectrometry were used to determine the concentration of trace metals in marine bivalveAnadaragranosa. A total of 11 elements: Mg, Cl, Mn, K, Se, Br, Zn, Co, Fe, Rb, Cd and Cu were detected. Analyses were performed to examine the relationship between metal concentration and body weight. Results from both techniques show linear relationship between total metal concentration and body weight.

Declines in density of one natural, three artificially-seeded and eight experimental populations of Anadara granosa were monitored over periods ranging from seven to twelve months. For three of four large populations the decline in density has been adequately described by a model of the form N t=N 0·e zt where N t is density at time t, N o is initial density and z is the instantaneous mortality coefficient. The mean value of the latter was found to be-1.88·yr−1 with 95% confidence limits-1.54 to-2.25. The data obtained from the experimental populations demonstrated that mortality is unaffected by initial densities upto 2,500·m−2, but increases as shore elevation decreases due at least partly to greater access by predators at the lower levels. The data on mortality rates have been combined with previously-published information on growth rates in order to arrive at estimates of production. At one of the artificially-seeded sites the 95% confidence limits of estimates of mean production are 24 and 62 g dry tissue·m−2·yr−1 with an average value of 42 g·m−2·yr−1. Examination of the effects of shore elevation on production revealed that the latter is greatest at the uppermost shore level studied because down-shore increases in growth rate are more than offset by increases in mortality. Production per individual has been shown to decrease with increasing density. This latter fact has been used to estimate the maximum possible production which, for one site 250 cm above chart datum, lies between 49 and 72 g·m−2·yr−1 (95% confidence intervals). It has been demonstrated that for one of the culture sites variation about an estimate of mean mortality rate does not contribute as much to the variation of the final estimate of production as does the variation about the estimates of the mean values of the constants in a growth equation. As far as possible production of Anadara granosa has been compared with values reported for other marine and estuarine bivalve molluscs and it is concluded that A. granosa may be considered moderately to highly productive.