Slime Molds in the Laboratory II: Moist Chamber Cultures

Abstract

In a previous article (see ABT, February 1982), I described the techniques involved in making field collections of the fruiting bodies of plasmodial slime molds, or Myxomycetes. Slime molds are common inhabitants of decaying plant material throughout the world. However, despite their abundance and widespread occurrence, relatively little use has been made of these fascinating and biologically enigmatic organisms in laboratory studies. There are a number of reasons why this is the case. First of all, because of their small size and the types of situations in which they occur, slime molds are easily overlooked in the field and thus are not familiar organisms to many biology instructors. Moreover, until the appearance of Farr's How to Know the True Slime Molds (1981), a fairly comprehensive and relatively nontechnical guide for the identification of slime molds simply did not exist. Also, the very fact that these organisms do not possess a particularly attractive common name probably hasn't helped matters! Although slime molds have considerable potential value in laboratory studies, as was pointed out in the previous article, some major constraints do exist in regards to making field collections of these organisms. First of all, since slime mold fruiting bodies tend to be most abundant during summer and early autumn for much of the United States, their period of max-. imum availability largely falls outside the academic year. Furthermore, many instructors who might otherwise make use of these organisms do not have access to the moist, forested areas where slime mold fruiting bodies are particularly abundant and thus most easily collected. However, laboratory studies of slime molds do not have to be restricted to material collected in the field (or purchased from a biological supply house). The purpose of this article is to describe a technique for obtaining slime molds (plasmodia as well as fruiting bodies) in the laboratory, using pieces of tree bark placed in moist chamber cultures. This technique is relatively easy to carry out and requires no special equipment. Moreover, it can be used at any time of the year and in any part of the country.