The postembryonic development of Centruroides ochraceus from Mexico

 

Happy New Year!

Wilson Lourenco and Eric Ythier have recently published some old observations of postembryonic development of Centruroides ochraceus (Pocock, 1898) (Buthidae) from Yucatan, Mexico. It is also suggested that parthenogenesis exists in this species.

Abstract:
Since general data on the biology of scorpions remain rare, we propose in this note some results on the postembryonic development of the buthid scorpion Centruroides ochraceus (Pocock, 1898), species distributed in the Yucatan peninsula, Mexico. The results were originally observed almost 40 years ago, based on some specimens collected by the senior author. A possible case of parthenogenesis is also suggested for this species.

Reference:
Lourenço WR, Ythier E. The postembryonic development of Centruroides ochraceus (Pocock, 1898) from Yucatan, Mexico (Scorpiones: Buthidae), with comments on parthenogenesis. Revista Iberica de Arachnologia. 2024(45):119-22. [Full text supplied by author]

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.

Abstract:
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.

References:
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!

 

Ovulation, fertilization and embryonic development in scorpions - a partial review

Yesterday I blogged about a new and interesting review on scorpion reproduction by professor Michael Warburg. Today, professor Warburg sent me another new review article that he as recently published on scorpion reproduction. The main topics of this publication is ovulation, fertilization and embryonic development in scorpions.

Abstract:
Ovulation, fertilization and both normal and arrested embryonic developments in scorpions, are reviewed and discussed. The importance of all three aspects in scorpion reproduction is discussed from both an evolutionary and an ecological outlook. The number of embryos varies within and among scorpion species and is not related to the female’s mass prior to parturition. There is a certain loss in embryo numbers and not all of them will become juveniles. The significance of this loss is discussed, and future avenues of research are suggested.

Reference:
Warburg MR. Ovulation, fertilization and embryonic development in scorpions: a partial review. African Entomology. 2012;20(1):60-8. [Subscription required for fulltext]

Thanks to professor Warburg for sending me this paper!

Reproduction in Chiromachus ochropus from Seychelles

There are too many scorpion species that we do not know anything about when it comes to their biology. because of this it is interesting to read the new paper from Lourenco, Leguin & Cloudsley-Thompson on the embryonic and post-embryonic development of Chiromachus ochropus (C. L. Koch, 1837) (Hemiscorpiidae) from Fregate Island, Seychelles.

Interestingly, this species can grow up to 120 mm i total length.

Abstract:
Observations have been made since the end of the 1990s on living scorpions of the species Chiromachus ochropus (C. L. Koch, 1837). These were collected by British biologists, on a field trip to Fregate Island, Seychelles. The total duration of embryonic development averaged 25 months. The moults necessary to reach the various juvenile instars and adulthood took place at average ages of 10, 242, 596, 925, 1763, 2310, 2661, 2957, 3313 and 3773 days. These developmental periods are remarkable longer than those previously observed in any other species of scorpions. Eleven instars were observed among the specimens that had been reared in captivity. This is unique among scorpions. Morphometric growth values of the different instars are significantly inferior to those in other species studied. A significantly larger size was observed in some of the females collected in the field, suggesting the occasional existence of at least one extra instar.

Reference:
Lourenco WR, Leguin E-A, Cloudsley Thompson JL. The embryonic and postembryonic developments of Chiromachus ochropus (C. L. Koch, 1837) (Scorpiones, Liochelidae) from Fregate Island, Seychelles. Entomol Mitt Zool Mus Hamburg. 2011;15(184):213-22.

Thanks to Wilson Lourenco and Gerard Dupre for sending me this paper!

Family Hemiscorpiidae