Differential distribution of genetic variants in triploid parthenogenetic Trichoniscus pusillus (Isopoda, Crustacea) in a heterogeneous environment

Based upon polymorphisms in the phosphoglucomutase and esterase loci, four different genotypes (i.e. clones) have been recorded in triploid parthenogenetic Trichoniscus pusillus. The distribution of genotypes was studied in five pairs of nearby sites where decaying beech leaves resp. spruce needles were the dominant constituents of the litter. Individual genotypes are associated with a particular type of litter and when nearby sites are compared, significant differences in the distribution of genotypes were observed in four out of the five cases. Since these nearby sites are within the potential range of each individual, it is concluded that different genotypes selectively exploit different subniches in a heterogeneous environment.