Ovarian and Hemolymph Ecdysteroids in the Terrestrial IsopodArmadillidium vulgare(Malacostracan Crustacea)

Abstract

Ovarian and hemolymph ecdysteroids inArmadillidium vulgarewere analyzed at four stages of ovarian maturation through the reproductive molt cycle using high-performance liquid chromatography and radioimmunoassay. The major ecdysteroids in the ovaries and hemolymph ofA. vulgarewere 20-hydroxyecdysone and ecdysone in free and conjugated forms. The concentration of ovarian ecdysteroids reached a maximal level in maturing ovaries during stage D (premolt period) of the molt cycle. At the end of stage D, a high level of ecdysteroids was detected in fully matured ovaries. On the other hand, hemolymph ecdysteroid titers in reproductive females showed a peak during stage D and declined rapidly to a low level at the end of stage D. No appreciable differences in the amounts of hemolymph ecdysteroids and in molecular species of them were apparent in females in reproductive and nonreproductive molt cycles. The amounts of hemolymph ecdysteroids were about fivefold higher in females than those in males. These ecdysteroids may have a role in controlling ovarian development in femaleA. vulgare.