抄録
We previously found that rheologic characteristics of blood from silkworm bred with mulberry change with the type of silkworm and the age of the silkworm. We have investigated here, the rheologic characteristics of blood from silkworm bred with artificial breeding, using a precision cone-plate type viscometer. Blood from artificial breeding silkworm showed non-Newtonian plastic flow with yield stress at a shear rate below 10 5 1, thereby suggesting that the blood has a structure arising from the interaction of blood constituents. Detailed rheologic analyses were performed using Casson's equation. Blood from mulberry-breeding silkworm showed a marked decrease in apparent viscosity at the initial stage of five age periods. However, blood from artificial breeding silkworm did not show these decreases in viscosity and more the viscosity was about twice that of blood from mulberry-breeding silkworm. Furthermore, blood from artificial breeding silkworm demonstrated a marked increase in apparent viscosity at the last stage of five age periods. These results clearly show that rheologic characteristics of silkworm bloods, accordingly the structure of blood, are strongly influenced by breeding. These findings may contribute to quantitative investigation of the biological process in silkworms.
