• The Korean Journal of Ecology
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• v.20 no.5
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• pp.355-365
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• 1997

Macrozoobenthic community structure was studied on the mud-tidalflat around Mokpo coastal area, Korea, from September 1995 to May 1996. Ten sampling stations were chosen along the 1km transect with a 100 m intervals. Triple macrozoobenthos sampling were conducted with a stainless box core sampler (size $13{\times}22{\times}30$ cm) at each station on the seasonal basis. A total of 119 species of macrobenthos was sampled with a mean density 2,357 $ind./m^2$ and biomass of 180. 94 $g/m^2$ during the study period. Of these species, there were 51 species of mollusce (43%), 36 of crustaceans (30%), 27 of polychaetes (23%). Molluscs were density-dominant faunal group with a mean density of 1,804 $ind./m^2$, comprising of 75% of the total density of the benthic animals. It was followed by polychaetes with 347 $ind./m^2$ (15% of the total density). Molluscs were biomass-dominant faunal group with a mean biomass of 147.51 $g/m^2$ (82% of the total biomass). The number of species, abundance and biomass showed increasing trends toward the lower intertidal stations from the higher stations. Major dominant species were Musculista senhousia (bivalve), Capitellidae spp. (polychaetes) with a density of 1,640 $ind./m^2$ and 179 $ind./m^2$ , respectively. The density of M. senhousia was more than 63% of the total density of benthic organism on the tidal area. Small gastropod Cerithideopsilla umumriensis was another dominant epifaunal species between st.1 and 2 with a mean density of 100 $ind./m^2$. Cluster analysis showed that the benthic community could be divided into three stational groups, that is, upper, middle and lower groups by the exposure duration.

• The Korean Journal of Malacology
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• v.14 no.2
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• pp.121-130
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• 1998

Studies on the distribution and growth of the mud mussel, Musculista senhousia, were carried out in the mud-tidal flat near Mokpo from August 1996 to July 1997. The patch distribution of the mussel was observed in the middle part of the tidalflat during the study period. Annual mean density was 8,215${\pm}$1,394 ind./m2 and annual mean biomass was 1,966.43${\pm}$668.49 g TWwt/m2 in total wet weight, 760.04${\pm}$279.13 gMWwt/m2 in meat wet weight, 209.93 ${\pm}$ 49.41 gMDwt/m2 in meat dry weight, and 109.66${\pm}$58.78 gAFDW/m2 in ash-free dry weight. The monthly mean size of shell length varied from 11.00 mm to 16.97 mm. Relationship between shell length (SL) and shell height (SH) showed a positively significant regression (SH=0.482SL+0.791, R2=0.940, P<0.001). Regressions of total wet weight (TWwt) (TWwt=7.601${\times}$10-5SL3.052, R2=0.905, P<0.001), and meat wet weight (MWwt) (MWwt=1.127${\times}$10-5${\times}$SL3.404, R2=0.784, P<0.001) on shell length were positively allometric, with highly significant correlation coefficient. The relationships between SL and meat dry weight (MDwt), and AFDW were MDwt=9.813${\times}$10-6${\times}$SL2.928 (R2=0.421), and AFDW=1.015${\times}$10-5${\times}$SL2.922(R2=0.810), respectively. The condition factor of the mussel has been increased from March and formed a peak in July and August. It was sharply dropped in September. These results suggest that the gonadal development of the species commenced to be occurred in spring and that main spawning occurred between August and September.