Polymorphism in Pseudoscorpions. II. Changes of abdominal segmentation pattern in Neobisium carpaticum Beier and Roncus pannonius Ćurčić, Dimitrijević and Karamata (Neobisiidae, Pseudoscorpiones).

Abstract

Polymorphism in abdominal sclerite pattern was studied in Neobisium carpaticum BEIER, 1935, and Roncus pannonius ĆURČIĆ, DIMITRIJEVIĆ et KARAMATA, 1992 (Neobisiidae, Pseudoscorpiones), both inhabiting Yugoslavia. A total of 58 examples of N. carpaticum and 57 specimens of R. pannonius, with changes of this pattern (1.53% and 0.87%, respectively) were found out of 3,794 and 6,570 specimens examined, respectively. Variation of sclerite pattern was confined mostly to adults and less to the subadult stages. In N. carpaticum, as many as 11 different single or combined changes in the sclerite pattern were noted; in R. pannonius, there were 14 types of such deviations. The most frequent variants in the two species were: partial atrophy, symphysomery, combined partial atrophy and symphysomery, and combined hemimery and sclerite enlargement; all other changes in the sclerite pattern were less frequent. Statistical analysis showed that only males of N. carpaticum and females of R. pannonius exhibit significant and marginally significant asymmetry in the changes of the sclerite pattern, respectively. Additionally, the adults (both females and males) of N. carpaticum exhibited marginal significance, while the adults of R. pannonius showed significant differences between the occurrence of changed abdominal segmentation on the left and right. The probable causes for this phenomenon were also discussed. Apart from some physical, mechanical, and chemical factors, it is assumed that both developmental and genetic factors cause the changes in the abdominal sclerite pattern.