The grass carp, a large herbivorous minnow from lowland rivers of eastern, is considered a long-term solution to control the over-growth of submersed aquatic plants. Particle & Surface Sciences are promoting the Micromeritics Elzone II, particle and cell size/count analyser, for this application.
Using grass carp to control aquatic vegetation is inexpensive. The grass carp, like most fish, are diploid. They possess two sets of chromosomes (one from each parent) and are capable of sexual reproduction. The potential of the diploid grass carp to reproduce naturally and over-populate ponds caused considerable controversy over its use as a biological control agent.
This risk led to the development of a method for the production of non-reproductive, triploid grass carp, that have three sets of chromosomes and are incapable of normal sexual reproduction and the production of viable offspring.
Concern exists, however, that induced polyploidy could result in a small percentage of some reproductive grass carp. The United States Fish and Wildlife Department have required anyone that produces and sells grass carp to perform inspection and 100% triploid certification to ensure that the grass carp are non-reproductive. Triploidy must be verified prior to stocking. This is done by measuring the volume of the nucleus of a red blood cell after the cell membrane has been chemically removed. The only way to accomplish this is with the ‘electrical sensing zone’ method (the analytical technique accepted by the U.S. Fish and Wildlife Department as well as other global agencies).
Micromeritics’ Elzone II 5390, distributed throughout Australia and New Zealand, is a particle and cell size/count analyser that utilises the ‘electrical sensing zone’ method (also known as the Coulter Principle) to determine the size, number, concentration, and mass of a wide variety of organic and inorganic materials. The Elzone II is a suitable inspection tool to quickly differentiate diploid from triploid grass carp. Fast analysis and low noise features have been designed into the Elzone II to specifically meet the needs of the grass carp industry. A real-time pulse display with automated cursors clearly distinguishes ploidy. Live histograms are also included.