Venezuelan arachnids. Two new species of the Tityus Genus (Scorpionida: Buthidae) and the chromatographic profile of venom as a possible taxonomical tool

Two new species of the Tityus genus are described. T. isabelceciliae n. sp lives on the northern central slope of the Cordillera de la Costa. It belongs to the discrepans group and is dangerous to man due to its high number, aggressive behavior, domiciliary habits, and high toxicity of its venom. T. isabelceciliae venom is similar to other Tityus in relation to the molecular weight range and the biological activity of its components. However, the proportions of each fraction in the venom pooled from many T. isabelceciliae differ from the proportions in other Tityus, indicating that these proportions may have a taxonomical value. The venom LD50 is 38.1 (36.3, 39.9) µg/g mouse (Death in 30 min, Dixon and Mood (14) sequential method, median and 95 per cent confidence interval, n=7). Venom production was 916 (625, 1213) µg protein per animal (n=38): females [944 (750, 1150) mg protein per animal, n=24] and males [824 (550, 112) mg protein per animal, n=14] did not differ in venom production (P>0.05). There was no correlation between animal total weight and venom production. T. rusmelyae n. sp. from the androcottoides group lives near the town of Humocaro Alto in the Lara State, Venezuela. The male specimens have clearly defined keels and granules. It differs from other species of this genus in that the prominent characteristics are observed in male specimens.

Arácnidos de Venezuela: una nueva familia: dos nuevos géneros y dos nuevas especies de opiliones laniatores / Arachnids of Venezuela: a new family: two new genera and two news species of laniator opilions

Se describe una nueva familia, dos nuevos géneros y dos nuevas especies de Opiliones Laniatores, los cuales son anoptalmos y hemiedáficos. Se caracterizan por la forma de los pedipalpos y de las II patas ambulatorias. Habitan bajo la corteza de tallos en descomposición. Se presentan tablas con los caracteres métricos y figuras ilustrativas de diversos caracteres morfológicos

Arácnidos de Venezuela: un nuevo género y dos nuevas especies de Schizomidae y redescripción de Schizomus simoni hansen y sorensen: 1905 del sistema montañoso de la Costa / Arachnids of Venezuela: a new genus and new species of Schizomidae and redescription of schizomus simoni hansen & sorensen: 1905 from coastal mountain range (Schizomida)

Se describe Stenoschizomus tejeriensis n. gen., n. sp, caracterizado por el dimorfismo sexual de los pedipalpos, una nueva especie del género Schizomus y se redescribe Schizomus simoni hansen y sorensen, 1905. Habitan en la región central del Sistema montañoso de la Costa. Se presentan tablas con caracteres métricos y dibujos ilustrativos

Aracnidos de Venezuela: Seis nuevas especies del género Tityus y redescripción de tityus pococki hirst, 1907 tityus rugosus (scenkel, 1932) N. Comb. y tityus nematochirus Mello- Leitao, 1940 (scorpionida : Buthidae) / Arachnids of Venezuela: Six new species of the genus tityus and redescription of tityus pococki hirst, 1907, tityus rugosus 1940 (scorpionida: Buthidae)

Seis nuevas especies del género tityus incrementan la escorpiofauna de Venezuela. Tityus pococoki hirst 1911 sustituye a tityus kraepelinianus Mello- Leit