13 November, 2020

Life history aspects of the buthid scorpion Tityus forcipula from Colombia

 Knowledge of the life history of an animal is important and for scorpions there are very few life history studies that cover most of the lives of a species. In a recent article Michael Seiter and co-workers present a study of the embryonic and post-embryonic development of Tityus forcipula (Gervais, 1843) (Buthidae) from Colombia under different climate regimes in the laboratory (which may follow the climate changes the world is now experiencing).

The results showed that  T. forcipula reared under laboratory conditions was not able to thrive under constant higher temperatures. This may be an indication that this species will be vulnerable for an increase in temperature due to global warming.

Observations on the entire life history of scorpion species are uncommon, and these studies primarily focus on postembryonic development. So far, little is known on how changes in temperature or humidity could affect communities of scorpions. Here, we present data on the embryonic and postembryonic development of Tityus forcipula (Gervais, 1843), a scorpion living in the Colombian Central Cordillera that was subjected to different climate regimes. For a comparative approach, one group was raised under lower conditions (23–248C) and another group was raised under higher temperatures (25–278C, meaning a 2–38C increase). Our results clearly demonstrate that T. forcipule reared under laboratory conditions is not able to thrive under constant higher temperatures. A minority of the latter group (, 10%) reached adulthood, but never reproduced. Of the 43 specimens kept under lower temperatures (with a mild diapause), 21 females and 19 males reached maturity in the 5th instar; only one female and two males required an extra molt to mature. Tityus forcipula specimens reached maturity after 463 days of postembryonic development. The average for embryonic development was 208 days, with an average of 12 neonates per litter. Twenty-four different morphometric measurements were taken from all specimens for each exuvium of the juveniles and the adult stage. The results indicated a relationship albeit partly poorly developed, between the sexes, in several measured structures and the instars.

Seiter M, Friedl N, Cozijn MA. Life history aspects of the buthid scorpion Tityus forcipula (Gervais, 1843) with remarks on its thermal limits. The Journal of Arachnology. 2020;48(2):161-8.[Subscription required for full text]

Thanks to Michael Seiter and Michiel Cozijn for sending me their article!


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