A new species in the genus Vachoniochactas from Colombia

A new species in the little known chactid genera Vachoniochactas has been described from Colombia, bringing the number of species in the genus up to four.

Vachoniochactas humboldti Florez, Botero-Trujillo & Acosta, 2008 [Chactidae]

This small scorpion (20-25 mm) is probably a leaf litter dweller.

The status of the genus is also discussed.

Reference:
Florez E, Botero-Trujillo R, Acosta LE. Descritpion of Vachoniochactas humboldti sp. nov. from Colombia, with complementary notes on the genus (Scorpiones, Chactidae). Zootaxa. 2008(1853):31-44.

Family Chactidae

How to keep Australian scorpions

Mark Newton, the editor of the great Aussi scorpion site, The spiral Burrow, has published a book about Aussi scorpions and their husbandery.

In addition to information about how to keep Aussi scorpions, the book also has a lot of general information about scorpions and their biology. The book has several color plates. ISBN number is 978-0-9804161-0-7.

I haven't received the book yet, but based on the information and previews on the book's promo page and my previous experiences with the author, I'm convinced that this will be a very interesting and informative book.

Australian scorpions are rarely available outside Australia due to the country's strict policy on animal exports, and this book is a great opportunity to get an insight into the scorpion fauna of Australia.

The book can be ordered from the book's promo page. PayPal payment is possible.

Are female scorpions better desert survivors than males?

It is well known that desert scorpions are among the best adapted arthropods inhabiting the warm and dry deserts of the world. Scorpions exhibit some of the lowest water-loss rates recorded for arthropods, and also have strategies for either tolerating increased haemolymph osmolarity or regulating the volum and consentration of the body fluid.

In a recent paper, Gefen (2008) shows that female Smeringurus mesaensis (Vaejovidae) actually is better than males in handling the though conditions in a desert environment. The females had larger hepatopancreas compared to males, and showed a considerably better osmoregulatory capacity. Females had higher hepatopancreas water content and higher mobilization rates of water from the hepatopancreas to the haemolymph during deccication.

Here is the abstract from the article:

The osmoregulatory and respiratory responses of male and female Smeringurus mesaensis (Vaejovidae) to prolonged desiccation were measured. No significant effect of sex on mass-loss rates (MLRs) was found. Still, females maintained their haemolymph osmolality when desiccated to 10% mass loss, whereas that of males increased significantly after loss of as little as 5% of initial mass. Females had a 3-fold larger hepatopancreas, significantly higher hepatopancreas water content and higher metabolic rates when adjusted to hepatopancreas-free dry mass. Thus, females not only store more water in the hepatopancreas but also mobilise it to the haemolymph at a higher rate during desiccation, thus maintaining haemolymph osmolality.

Gas exchange rates of both males and females decrease as desiccation progresses. An initial respiratory exchange ratio (RER) of 0.9 is followed by a significant increase at mass loss levels of 7.5% and higher. RER values greater than 1.0 may result from partial shift to anaerobic catabolism, which allows closure of the book lung spiracles for longer duration, thus minimising respiratory water loss.

The effects of gas exchange rates on rates of water mobilisation between body compartments and water loss to the environment suggest a trade-off between maintaining osmotic stability and conserving body water stores under stressful conditions.

Reference:
Gefen E. Sexual dimorphism in desiccation responses of the sand scorpion Smeringurus mesaensis (Vaejovidae). J Insect Physiol. 2008;54(5):798-805. [Subscription required for fulltext]

Taxonomical updates

Three new papers has recently been published with new species and taxonomical updates:

Teruel & Roncallo (2008):

Ananteris hasshy Teruel & Roncallo, 2008 (Buthidae) from Colombia (new species).

Teruel & Rodriguez (2008):

Didymocentrus armasi Rolando & Rodriguez, 2008 (Scorpionidae) from Cuba (new species).
Didymocentrus jaumei Armas, 1976 (Scorpionidae) from Cuba (restored species status).
Didymocentrus sanfelipensis Armas, 1976 (Scorpionidae) from Cuba (restored species status).

Lourenço, Qi & Goodman (2008):

Tityobuthus betschi Lourenço, Qi & Goodman, 2008 (Buthidae) from Madagascar (new species).
Tityobuthus chelbergorum Lourenço, Qi & Goodman, 2008 (Buthidae) from Madagascar (new species).
Tityobuthus mccarteri Lourenço, Qi & Goodman, 2008 (Buthidae) from Madagascar (new species).

This paper also has a historical review of the genus Tityobuthus and a redescription of Tityobuthus baroni (Pocock, 1890).

In other news:

Lourenco (2008) has described the male of Chaerilus agilis Pocock, 1899 from Malaysia.

Teruel (2008) has confirmed the occurence of Centruroides gracilis (Latreille, 1805) in Jamaica.

The gallery of the Scorpion Files has recently been updated with several new pictures of rarly seen species. A big thanks to all that have submitted pictures to the Scorpion Files!

References:
Teruel R, Roncallo CA. A new species of Ananteris Thorell, 1891 (Scorpiones: buthidae) from the Caribbean region of Colombia. Euscorpius. 2008(72):1-7. [Free fulltext]

Teruel R, Rodriguez TM. La subfamilia Diplocentrinae (Scorpiones: Scorpionidae) en Cuba. Quinta parte: el genero Didymocentrus Kraepelin 1905. Boletin Sociedad Entomológica Aragonesa. 2008(42):53-78. [No fulltext]

Lourenco WR, Qi JX, Goodman SM. The identity of Tityus baroni (Pocock, 1890) (Scorpiones, Buthidae) and description of three new species from Madagascar. Boletin Sociedad Entomológica Aragonesa. 2008(42):89-102. [No fulltext]

Lourenco WR. Description de mâle de Chaerilus agilis Pocock, 1899 (Scorpiones, Chaerilidae). Boletin Sociedad Entomológica Aragonesa. 2008(42):139-42. [No fulltext]

Teruel R. Confirmation of the occurence of Centruroides gracilis (Latreille 1805) (Scorpiones: Buthidae) in Jamaica. Boletin Sociedad Entomológica Aragonesa. 2008(42):370. [No fulltext]

Family Buthidae
Family Scorpionidae
Family Chaerilidae

Taxonomical changes in Vaejovidae

Soleglad & Fet has recently published several changes in the family Vaejovidae:

Hoffmannius Soleglad & Fet, 2008 is a new genus that accomodates 17 species previously placed in Vaejovis.

Kochius Soleglad & Fet, 2008 is a new genus that accomodates 10 species previously placed in Vaejovis + the new species Kochius kovariki Soleglad & Fet, 2008.

Thorellius Soleglad & Fet, 2008 is a new genus that accomodates four species previously placed in Vaejovis. In addition, two species are raised from subspecies to species rank: Thorellius atrox (Hoffmann, 1931) (previously Vaejovis intrepidus atrox Hoffmann, 1931) and Thorellius cristimanus (Pocock, 1898) (previously Vaejovis intrepidus cristimanus Pocock, 1898).

Wernerius Soleglad & Fet, 2008 is a new genus that accomodates two species previously placed in Vaejovis.

Details about the changes and the contents in the new genera can be found in The Scorpion Files' Vaejovidae Updates and the Vaejovidae family page.

The authors also establish a new subfamily (Smeringurinae) with two new tribes (Smeringurini and Paravaejovini). Check out the paper for further details.

References:
Soleglad ME, Fet V. Contributions to scorpion systematics. III. Subfamilies Smeringurinae and Syntropinae (Scorpiones: Vaejovidae). Euscorpius. 2008(71):1-115. [Free fulltext, but large file (30 MB)]

Family Vaejovidae

Foraging activity and behavior in Mesobuthus gibbosus

Kaltsas, Stathi & Mylonas have recently published a study on the foraging activity of Mesobuthus gibbosus on two greek islands (Crete & Koufonisi). Here is the abstract from the paper:

The foraging activity of Mesobuthus gibbosus was studied and analysed over 290 field samplings in Koufonisi island (central Aegean) and Crete (south Aegean) during the period of maximal activity of the species. The results showed that on both islands males and juveniles searched for prey mainly relatively near or far from their burrows (“sit-and-wait” strategy), whereas females foraged comparatively more than males and juveniles at the entrances of their burrows (“doorkeeping” strategy). Throughout the study, there was no evidence of two or more individuals foraging together. Re-emergence time after digestion lasts probably more than one month, because no individual was observed foraging twice in the 30 consecutive days of the study period. The individuals that followed the sit-and-wait strategy were larger in size compared to those of the same sex or age-class that used the doorkeeping strategy. The diet of the species was wide, including representatives of eight arthropod orders on Koufonisi and seven on Crete. Stinging was selective and prey selection was based on the age-class of the predator and the size of the prey compared to the size of the predator. The success of sit-and-wait foraging individuals was much more dependent on abiotic factors compared to scorpions using the doorkeeping strategy. Moon phase, air and soil temperature and air relative humidity were the abiotic factors which mainly influenced the foraging activity of these generally non-cannibalistic opportunistic ambush predators on both islands.

It is great to see some studies on scorpion behavior and ecology being published as there are too few of this kind these days when the main focus seems to be on taxonomy and scorpionism (scorpions of medical significance).

References:
Kaltsas D, Stathi I, Mylonas M. The foraging activity of Mesobuthus gibbosus (Scorpiones : Buthidae) in central and south Aegean archipelago. Journal of Natural History. 2008;42(5-8):513-27 [Subscription required for fulltext]

A species biography for Rhopalurus laticauda is published in The Scorpion Files

Michiel Cozijn has written another species biography for The Scorpion Files:

Rhopalurus laticauda (Thorell, 1876) species biography

The biography has been reviewed by a couple of experts on the genus, and should be interesting both professionals and hobbyists (the biography has a section on captive care).

Michiel has previously written biographies for the following species:

Babycurus gigas (Kraepelin, 1876)
Babycurus jacksoni (Pocock, 1890)

A big thanks to Michiel for supporting The Scorpion Files in this way!