Polysphondylium from forest soils of Tikal, Guatemala

Abstract

Seven of 35 different taxa of dictyostelid cellular slime molds recovered from forest soils of Tikal, Guatemala, belong to the genus Polysphondylium. Four of these are new species (P. acuminatum, P. asymetricum, P. colligatum, and P. tikaliensis). They inhabit the soil environment of the forest immediately surrounding the principal Mayan ruins together with three previously described species (P. violaceum, P. pallidum and P. pseudo-candidum). These species are part of the largest collection of dictyostelids obtained from soils of a single forest. The environmental conditions of this forest appear optimal for cellular slime mold coexistence, particularly for the Polysphondylia, since no other comparable area has yielded as many species of Polysphondylium. A morphophysiological comparative chart contrasts the new taxa with the other Polysphondylia present at Tikal; a key to species summarizes their taxonomy.

Key Words:

• dictyostelids
• systematics
• taxonomy
• tropical ecology