• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.1
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• pp.43-48
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• 2010

This study was designed to evaluate whether the addition of sediment improvements with natural materials to water tanks influenced the hematologic properties and muscle glycogen content of the blood cockle, Tegillarca granosa under laboratory conditions. Following a 10-d matured period of sediment improvements, blood cockles were subjected to 4 groups (0, 100, 300, $800\;g/m^2$) of sediment improvements for 14-d Only one individual died at $800g/m^2$ after 48-h Whole blood, hematocrit value and hemoglobin concentration of blood cockle were changed little by sediment improvements, however, both glucose and glycogen were increased more compared with those of the control groups.

• Journal of Aquaculture
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• v.19 no.2
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• pp.119-124
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• 2006

We investigated appearance tidal time and line of spats blood cockle, Tegillarca granosa. And we observed appearance individual numbers and shell growth of spats blood cockle, T. granosa on the several tidal lines and time for the highly valued aquaculture business. Most of the blood cockle spats distributed on the $2{\sim}3 $ hours tidal line. The shell growth was high on the $1{\sim}3$ hours tidal line. But we found small amount of spats on the $5{\sim}6$ hours tidal line. The shell length of spats became $4.7{\pm}1.0 mm$ in December, $5.2{\pm}1.2 mm$ in January, $5.4{\pm}0.9 mm$ in May, $8.5{\pm}0.8mm$ in June, $12.6{\pm}1.1 mm$ in July, $16.0{\pm}2.1 mm$ in August, $18.6{\pm}1.4 mm$ in September and $20.3{\pm}1.3 mm$ in October. As well, we could reconfirm of newly appearance blood cockle spats in the next October.

• The Korean Journal of Malacology
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• v.22 no.2
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• pp.135-141
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• 2006

This paper describes relative age and growth pattern of the blood cockle, Tegillarca granosa (Linnaeus) in Yeoja Bay, southern coast of Korea. The young shell of blood cockle that spawned from July to August reached 5.60 mm $({\pm}\;1.07)$ in shell height in October. Slow growing season was estimated to be from October to the next May with water temperature under $23^{\circ}C$. With warm water temperature in July to September, the growth was fast. The young shells reached 29 percentage of asymptotic shell height 11-15 months after spawning. Growth was estimated by von Bertalanffy growth function as follows. $I_t(sh_t)=46.1317\;(1-e^{-0.4997(t-0.5828)})$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.4
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• pp.251-256
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• 2005

For blood cockle Tegillarca granosa acclimated to winter and summer seasons, survival, temperature tolerance and physiological changes at different individual size were investigated for their temperature tolerances by increasing and decreasing temperature at a rate of 1, 2 and $3^{\circ}C/day$. The survival rate of adults and juveniles T. granosa acclimated to winter temperatures began to decrease from $32^{\circ}C$ and all experimental animals died between $37-39^{\circ}C$. In the case of animals acclimated to summer temperatures, the survival rates of adults and juveniles began to decrease from $35^{\circ}C$, and all died at temperatures between $40-44^{\circ}C$. The upper $LT_{50}$ was $27.72^{\circ}C$ for adults and $28.36^{\circ}C$ for juveniles. On the other hand, when the temperature was decreased from $4^{\circ}C\;to\;0^{\circ}C$ in order to investigate lower temperature tolerances, the survival rate of T. granosa was more than $70\%\;at\;2^{\circ}C$ for 25 days. Lower L T 50 was $2.09^{\circ}C$ for adults and $2.34^{\circ}C$ for juveniles. There was no effective difference in temperature tolerance between adults and juveniles. Filtration and respiration rates of T. granosa showed a similar aspect with increase and decrease of temperature. Filtration and respiration rates exhibited irregular conditions of a broken biological rhythm as the group acclimated to winter $(10 ^{\circ}C)$ and summer $(25^{\circ}C)$. In the case of decreasing temperature, filtration and respiration rates of T. granosa reduced to a minimum below $6^{\circ}C$

• The Korean Journal of Malacology
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• v.27 no.3
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• pp.205-211
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• 2011

This study presents physiological rates of oxygen consumption, ammonia excretion, feeding rates, O/N ratio and assimilation efficiency of the blood cockle, Scapharca subcrenata, determined from specimens collected in Yeoja bay on the south coast of Korea. Physiological parameters were measured monthly under static, laboratory controlled conditions with ambient conditions, and measurements were performed seasonally in order to estimate scope for growth and its probable sources of variation. Oxygen consumption and ammonia excretion rates have been increased as temperature increased with the highest value of August, 2008. Feeding rate was the highest during April whereas the lowest was during August which is a period of gametogenesis with minimum biomass of phytoplankton around sampling area. Assimilation efficiency was not significantly different seasonally and O/N ratio decreased during July to August. The scope for growth was negative during high temperature months(July to August), reflecting the high temperature and low feeding rate, and had its highest positive values during spring and autumn. Data on the physiological parameters and scope for growth of Scapharca subcrenata obtained in this study will be used to assess the carrying capacity for blood cockle cultivation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.8
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• pp.579-592
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• 2020

This study was designed to assess the water quality and phytoplankton community including chlorophyll a in blood cockle (Tegillarca granosa) farms in May, August and November of 2017 in the northwestern Yeoja Bay, Korea. As a result, the seasonal characteristics of water types by water temperature and salinity were clear. Nutrients were abundant in silicate throughout the season, but phosphate was scarce in spring and summer, and nitrogen sources were scarce in autumn. The species composition of phytoplankton community was a very simple distribution, and the standing crop was also very low. The annual dominant species is dominated by the diatoms, with Skeletonema costatum-ls, Nitzschia longissima in spring, Pleurrosigma normanii, Coscinodiscus gigas in summer, and N. longissima, Pseudonitschia pungens, Chaetoceros curvisetus, Eucampia zodiacus in autumn. In summer the results were different from other coastal waters of Korea. The principal component analysis(PCA) and correlation analysis showed that the characteristics of water quality and biological environments differed according to the season. Furthermore, it was determined by the supply of materials through fresh water on land, seawater congestion caused by the refueling of surface sediments with lower depth, and the balance of biological production and mineralization of organic matters in blood cockle farms.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.299-309
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• 2019

This study was designed to assess the quality and quantity of food resources such as the chlorophyll a concentration (Chl-a), the particulate organic carbon (POC) and the particulate organic nitrogen (PON), on blood cocke (Tegillarca granosa Linnaeus) farms from May to November 2017 in the northwestern area of Yeoja Bay, Korea. The values of Chl-a, POC and PON were $1.69-7.68{\mu}g{\cdot}L^{-1}$ (average: $3.48{\mu}g{\cdot}L^{-1}$ in the surface), 0.88-2.58 mM (average: 1.97 mM) and 0.17-0.90 mM (average: 0.54 mM), respectively, and these values were higher in the spring and summer and lower in the autumn. Furthermore, Chl-a and POC had higher values on the bottom layer than those vales on the surface, while PON had higher values on the surface than those values on the bottom. The POC/PON ratio and POC/Chl-a ratio were 1.56-7.88 (average: 3.71 on the surface of the water) and 216-967 (average: 700 on the bottom of the water), respectively, with most of the carbon sources being sediment-accumulated particle organic matter, and the contribution by phytoplankton was assessed as being low. These results show that the food source of the blood cockle farms in the northwest area of Yeoja Bay seems to be abundant in quantity, but this is considered to be very poor in quality.

• The Korean Journal of Malacology
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• v.26 no.3
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• pp.171-177
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• 2010

We examined physiological responses related to the survival, oxygen consumption and filtration rate of the blood cockle, Tegillaarca granosa as a result of salinity changes. The 44-day $LS_{50}$ (median lethal salinity) at $10^{\circ}C$ for adult and juvenile was 15.8 (confidence limits 13.5-18.2 psu) and 16.2 (confidence limits 14.1-18.4 psu) psu respectively, whereas the 11-day $LS_{50}$ at $25^{\circ}C$ for adult and juvenile was 16.8 psu (confidence limits 12.9-21.2 psu) and 22.4 (confidence limits 20.5-24.7 psu) psu respictively. In conditions of decreasing salinity, Oxygen consumption and filtration rates decreased or varied irregularly as salinity decreased. The results of this study could prove important in investigating causes of mass mortality and managing shellfish aquaculture farms.