Segmental anomalies in Roncus aff. lubricus L. Koch, 1873 (Neobisiidae, Pseudoscorpiones), from Yugoslavia

Abstract

Malformations in the abdominal segmentation patterns were studied in two pseudoscorpion species of the genus Roncus L. Koch, inhabiting Yugoslavia. A total of 36 abnormal examples were found out of 4,825 specimens examined. All anomalous pseudoscorpions were dissected and subjected to the pathomorphological analysis. The frequency of the aberrant specimens was variable, depending on the locality, growth stage, sex, and species. The following malformations were noted: hemimery; partial atrophy (single and multiple); symphysomery (single and multiple); and combinations of different anomalies (combined hemimery and sclerite enlargement; combined hemimery and symphysomery; combined partial atrophy and symphysomery; combined partial atrophy and sclerite enlargement; combined atrophy or hemimery, symphysomery and sclerite enlargement; combined atrophy, symphysomery, helicomery and sclerite enlargement; and combined atrophy, helicomery and sclerite enlargement). Teratological variation of the abdominal sclerites has been confined mostly to adults and, to a lesser degree, to tritonymphs. In addition, some specific features of the relative distribution of various segmental deficiencies are considered. Finally, the probable causes of the genesis and development of segmental anomalies in the pseudoscorpions studied have been also discussed.