• Animal cells and systems
• /
• v.1 no.1
• /
• pp.15-23
• /
• 1997

Two new species of poecilostomatoid copepods, each belonging to the genera Myicola (Myicolidae) and Conchyliurus (Clausidiidae), are described, based on specimens taken from the mantle cavity of the bivalve Dosinella penicillata (Reeve). The host bivalve was collected from the intertidal mud flat near Inchon in the Yellow Sea.

• Parasites, Hosts and Diseases
• /
• v.46 no.2
• /
• pp.101-104
• /
• 2008

Metacercariae of Acanthoparyphium marilae Yamaguti, 1934 (Digenea: Echinostomatidae) were discovered in an intertidal clam, Mactra veneriformis, in a southwestern coastal area of the Republic of Korea. A total of 128 metacercariae were detected from 10 clams examined. They were round, 320 m in average diameter, with 23 collar spines. They were fed experimentally to chicks, and 10 days later adult flukes were obtained. The adults were morphologically characterized by the head collar with a single row of 23 dorsally uninterrupted spines, without special end group spines, a round ventral sucker, 2 round and tandem testes, and vitellaria extending at lateral fields from the posterior extremity not beyond the middle level of the posterior testis. The most characteristic feature of this species was the limited distribution of vitellaria, which differs from Acanthoparyphium tyosenense Yamaguti, 1939, the metacercariae of which are encysted in the same mollusk species. This is the first report in which the metacercariae of this species were detected, and the intertidal bivalve, M. veneriformis, has been identified as a second intermediate host for A. marilae.

• The Korean Journal of Malacology
• /
• v.17 no.2
• /
• pp.95-104
• /
• 2001

To determine optimal conditions for measurement of the clearance rate in feeding experiment of an intertidal bivalve Glauconome chinensis, effects of starvation, extent of mixing at subsampling, and initial prey concentration were assessed. Experiments were conducted separately for each condition with different treatments. Two-way ANOVAs showed that there were significant differences in clearance rates among different starvation periods (p<0.001), extents of mixing (p = 0.005), and prey concentrations (p < 0.001). Starvation for 1 or 2 days gave rise to 2 to 3-fold increase in the clearance rate. After starvation for 5 days, the clearance rate decreased seriously, implying loss of physiological status. It is suggested that animals should be fed during acclimation. The differences of the clearance rates between gentle and vigorous mixings were significant, but the differences were smaller than that among different incubation times. It was found that vigorous mixing is not necessary. The effect of initial prey concentration was great. However, optimal prey concentration could not be determined at any fixed value. Experiments with multiple concentrations of algal prey are recommended. Optimal incubation time for measurement of the clearance rate of G. chinensis was determined to be 2-4 hours.

• The Korean Journal of Malacology
• /
• v.31 no.3
• /
• pp.221-232
• /
• 2015

Observations in beach, intertidal and upper subtidal environments in Peter the Great Bay (north-western East Sea) have shown that attached algae were found on empty shells of 13 species of epifaunal and infaunal bivalve mollusks. Thirteen algae species were identified on empty dislodged shells but more than 50 species are known to be epibiotic on living bivalves. The dislodgement of shells with attached algae takes place in semi-enclosed, low-energy areas, as well as those which are open and affected by strong wave action, indicating the large scale of this phenomenon. The significance of seaweed transportation of living mollusks and their empty shells in the coastal zone, involving both taphonomic and ecological processes, is stressed. Algae appear to be a taphonomic agent and play a similar role as compared to birds or hermit crabs, but they act passively and contribute to environmental mixing in death assemblages in coastal environments.

• Proceedings of the Malacological Society of Korea Conference
• /
• 2002.11a
• /
• pp.17-18
• /
• 2002

• The Korean Journal of Malacology
• /
• v.24 no.2
• /
• pp.81-87
• /
• 2008

Distribution, population structure, and growth of the bivalve Protothaca euglypta were investigated for clams collected from the northwestern part of the East Sea of Russia. This species is distributed in further northern area than it was found earlier. In the southern area, this clam is found in the intertidal zone, up to 8 m in depth. It is one of the most numerous infaunal species of bivalves, and protected to wave action in the gravel-pebble and sand with rubble biotope. Population density of P. euglypta reaches 500 $spc./m^2$, and biomass 2 $kg/m^2$. Size and age composition of the local settlements and allometric growth of P. euglypta depend on a biotope. The growth rate of P. euglypta considerably reduces in case of the northern boundary area, whereas life span increases.

• Fisheries and Aquatic Sciences
• /
• v.6 no.2
• /
• pp.66-73
• /
• 2003

To understand the physiology of a suspension-feeding bivalve and its potential impacts on the dynamics of red tides on tidal flats, rates of clearance and ingestion of Glauconome chinensis were measured as a function of algal concentration, when the bivalve was fed on a nontoxic strain of red tide dinoflagellate Prorocentrum minimum, Cochlodinium polykrikoides or Scrippsiella trochoidea. With increasing algal concentration, weight-specific clearance rate increased rapidly at lower concentrations and after reaching the maximum at ca. 0.2 to 1.0 mgC/L, it decreased at higher concentrations. Maximum clearance rate was nearly equal for different algal species and ranged between 2.1 and 2.6 L/g/hr. Weight-specific ingestion rate also increased at lower algal concentrations but saturated at higher concentrations. Maximum ingestion rate was 2 to 10 fold different with different algal species: S. trochoidea (10.1 mgC/g/hr), P. minimum (3.9 mgC/g/hr), and C. polykrikoides (0.99 mgC/g/hr). Nitrogen and protein content showed that S. trochoidea is the best among the tested three red tide dinoflagellates. The maximum filtration capacity, calculated by combining the data on ingestion rate from laboratory experiments and those from the field for the density of the bivalve and the red tide dinoflagellates was 4.7, 1.4, and 25.3 tons/m2/day for P. minimum, C. polykrikoides, and S. trochoidea, respectively. It is hypothesized that the abundant suspension-feeding bivalves in tidal flats can effectively mitigate the outbreak of red tides.

• Fisheries and Aquatic Sciences
• /
• v.5 no.3
• /
• pp.183-190
• /
• 2002

To determine the effect of body size on the clearance rate and ingestion rate of small intertidal bivalves, Glauconome chinensis, feeding experiments were conducted on individuals of 12 different size classes, from 4 to 16 mm in shell length. Relationships between morphological parameters were also determined. The clearance and ingestion rates of G. chinensis responded similarly to their body size, ranging from 1.3 to 28.2 mL/hr/ind. and from 24.0 to 458.5, ${\mu}gC/hr/ind$., respectively. Both rates increased significantly (p<0.001) as shell length increased from 4 to 9 mm, although neither rate changed significantly when shell length was in the range from 12 to 16 mm. The weight-specific clearance rate $(CR_w)$ and ingestion rate $(IR_w)$ decreased with increasing body size, with values from 1.0 to 3.1 L/hr/g and from 17.9 to 51.3 mgC/hr/g, respectively. The $CR_w$ of G. chinensis was intermediate compared to those of larger bivalve species. The clearance rate (CR) relative to flesh dry weight (FDW) of G. chinensis were fitted well to the power function: $CR=0.43\times(FDW)^{0.71}\;(r^2=0.89)$. The exponent of fitting equation (0.71) of G. chinensis was higher than those of Mytilus edulis (Walne, 1972), Crassostrea gigas (Walne, 1972), and Placopecten magellanicus (MacDonald and Thompson, 1986).

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.23 no.6
• /
• pp.457-467
• /
• 1990

Sessile barnacle, Balanus trigonus Darwin, was collected from the intertidal rocks and the external shells of bivalve Mylius coruscus. The nauplius and cyprid larvae were cultured in a constant temperature cabinet at a temperature of $20^{\circ}C$ and a light regime of 14 h light and 10 h darkness. Larval development includes the six nauplius stages and a cyprid stage prior to settlement and metamorphosis to the young adult. Morphological characteristics including antennules, antennae and mandibles are described and illustrated. All nauplius larvae have trilobed labra typical in balanoides. The developmental time taken from newly hatched nauplius I to cyprid was $9\~13$ days and averaged 11 days.

• Journal of Aquaculture
• /
• v.8 no.2
• /
• pp.99-115
• /
• 1995

The food organisms of bivalve, Mactra veneriformis Reeve were investigated, from August 1993 to July 1994, at an intertidal sandflat area in shore of Kunsan. In the digestive track of M. veneriformis, total 60 genera (120 species) were found and consisted of both 52 phytoplankton genera (31 Diatoms, 7 Dinophyceae, 6 Chrysophyceae, 5 Cyanophyceae, and 3 Chlorophyceae) and 8 zooplankton genera (4 Radiolaria, 2 Ciliata, and 2 Crustaceae). The number of planktons species from digestive track readed the peak in March and October, and that in August is the lowest. The dominant planktons of the environment and the digestive track of M veneriformis are not coincidence. These planktons were roughly divided into two tropes as round and bar. The former was less than $200{\mu}m$ in diameter and the latter less than $20{\mu}m$ in diameter and $500{\mu}m$ in length.