Growth morphology of the filtering apparatus of silver carp ( Hypohthalmichthys molitrix) : I. Gross anatomy state

Abstract

In planimetric studies on the filtering and respiratory parts of individual gill arches of the right-hand-side gill apparatus of 30 silver carps aged 1, 2 and 3 years it was found that: 1. (1) The area of the respiratory part increased from the first to the fourth gill arch in all age categories; the area of the filtering part increased from the first to the third arch. 2. (2) The total area of the filtering part of the right-hand-side filtering apparatus was 390, 1440 and 2130 mm 2 in 1-, 2- and 3-year-old silver carps. In 2- and 3-year-old fish the increase corresponded to 264.5 and 439.2% respectively. 3. (3) In the second year the growth rate of the filtering part is 10% higher than that of the respiratory part. In the third year the relative growth of the filtering part decreased while that of the respiratory part markedly increased. 4. (4) In 2- and 3-year-old fish the ratio between filtering and respiratory parts was 2:1 and 3:2, respectively.