Isoelectrofocusing of organic esterases in the postnatally developing and adult ovoviviparous teleost, Poecilia reticulata.

In the ovoviviparous teleost, Poecilia reticulata, the esterases give rise to around 13 variants when separated by electrofocusing. These variants show histochemical characteristics (e.g. substrate utilization and sensitivity to inhibiting substances) which can be related to postnatal developmental stages and to adult sex. A few variants, moreover, appear to be typical of the stage examined (newborn, young, adult male and female). Very few variants can be classified by the criteria of Masters and Holmes (1975).