ABSTRACT
Parthenogenesis, a rare phenomenon in Chelicerates, apart from mites, is reviewed in scorpions, notably Tityus serrulatus Lutz & Mello from Brazil, Tityus columbianus (Thorell) from Colombia and Tityus metuendus Pocock from Peru and Brazil. Thelytokous parthenogenesis (with all-female broods) is most often observed. The only known exception to this is T. metuendus in which arrhenotoky (all-male broods) has been observed. In the present paper, current ideas regarding parthenogenesis in scorpions are summarized. The notion of geographic parthenogenesis ('parthénogenèse géographique'), coined by Vandel in 1928, is discussed. This rule is tentatively exemplified by a new case of parthenogenesis reported in a scorpion of the genus Tityus C. L. Koch, inhabiting 'Pico da Neblina' in Brazil / Venezuela.(AU)
Subject(s)
Parthenogenesis , Scorpions , HistoryABSTRACT
In this paper further information concerning the ecological and biogeographical aspects of scorpionism is presented. Some of the information already outlined in three previous publications (10,14,16) is assessed, and new data given concerning the pattern of distribution presented by Tityus serrulatus in Brazil. Some new ideas are also proposed regarding the possible evolutionary advantages and disadvantages of parthenogenesis versus sexuality in both the short-term and the long-term.
Subject(s)
Animals , Brazil , Residence Characteristics , Ecology , Parthenogenesis , Reproduction , Scorpions , Spider Bites/epidemiologyABSTRACT
Recently public health problems resulting from scorpion stings have shown an alarming increase in various tropical and subtropical countries such as Brazil, Mexico, Tunisia and Morocco. In some regions of Brazil, particularly in the States of Minas Gerais. Säo Paulo, Bahia, Goiás and the Federal District, more than 6000 scorpion stings with over 100 deaths were reported during a three-year period. In this paper, we attempt to demostrate the effects of human activities on the environment and their consequences on the distribution of dangerous species of scorpions. This topic is discussed in relation to the evolutionary ecology, life history strategies and asexual reproduction of scorpions.