서해연안 조간대에 서식하는 두졸망둑 Tridentiger trigonocephalus의 섭식생태

Feeding Habits of the Tridentiger trigonocephalus from the Coast Intertidal Zone in the West Coast of Korea

In order to know the food chain of a coastal organism community, the feeding habits of the Tridentiger trigonocephalus from the coast intertidal zone, Dodun-ri, So-myon, Sochon-gun, Chungnam in the West Coast of Korea were studied. T trigonocephalus were collected in the Dodun-ri from July 1993 to June 1994, and the habitat environment was investigated monthly. The feeding habits were studied through analyzing stomach contents of the T. trigonocephalus. The results were as follows; 1. The water temperature, sediment temperature, salinity, seawater pH, sediment pH, sediment water content and sediment organic content (or this studied period were in the range 5.0~34.8℃, 4.2~30.4℃, 23.30~28.01% 7.8~8.2, 8.3~9.2, 46.2~67.3% and 1.46~2.23%, respectively. 2. The major food item of the T. trigonocephalus was copepods and the food composition rate of copepods was 50.92%. 3. Ratio of stomach contents weight of T. trjgonocephalus was 2.43%(mean), fullness of stomach was increased twice a day in the morning and the afternoon. 4. The most abundant species in major food items was Acartia sp. in spring, that was Acartia sp. in summer, that was Calanus sinicus in autumn and that was Paracalanus parvus in winter. 5. Degree of overlapping expressed by Horn's index between seasons on the food items was above 0.6 between spring and summer. spring and autumn. summer and autumn. and the all of rest between seasons were below 0.6. 6. Degree of overlapping expressed by Horn's index between the body length groups on food items was above 0.6 in all fishes, there were little differences between the body length groups. 7. The composition of major food items according to the body length showed mostly the order of occurrence rate of copepods, decapods, molluscs and Cirripedia larvae ete.. As fishes grow longer. the occurrence rates of amphipods. Polycheata larvae, isopods, cumacens and stomatopods ect, were raised gradually. 8. The index of diversity of food items according to the body length was 4.214(mean), that was repeated increase and decrease irregularly by increment of the body iength. 9. The index of importance in the major food items was 0.354(Acartia sp.), 0.296 (Calanus sinicus) and O.188(Paracalanus parvus), the most important food organism was copepods in the T. trigonocephalus studied in this period.