Gestation period and litter size in Leiurus quinquestriatus

Luc Ross has recently published a research note on the gestation period and litter size in Leiurus quinquestriatus (Buthidae).

Abstract:
The following notes on gestation periods and litter size in seven specimens of Leiurus quinquestriatus are presented as observational data. Specimens of Leiurus quinquestriatus from southern Egypt and southern Israel were mated in the laboratory during 2007; afterwards, gestation periods and litter sizes of all females were recorded. Previous studies on this species reported that the gestation period ranged from 150 to 155 days and that litter size was between 12 and 99 offspring. In the present study, gestation periods in specimens from both geographic regions varied from 155 to 227 days and litter sizes were between 35 and 87 offspring. The current contribution expands on previously published data on gestation periods and supports previously reported litter size in Leiurus quinquestriatus.

Reference:
Ross LK. Notes on gestation periods and litter size in the arenicolous buthid scorpion Leiurus quinquestriatus (Ehrenberg, 1828) (Scorpiones: Buthidae). Journal of Venomous Animals and Toxins Including Tropical Diseases. 2009;15 (2):347-52.

Family Buthidae

Scorpion envenomations in children i Morocco

Even though most scorpions cause only mild and local symptoms, a few species do cause more serious symptoms in some parts of the world. And in most of these cases there are young children involved.

Scorpion stings are a public health problem in many countries in North Africa and the most serious cases usually involve Androctonus, Buthus and Leiurus. Abourazzak and co-workers have now published an epidemiological study looking on scorpion stings in children in Morocco. The results are quite alarming, showing that children are more vulnerable to scorpion stings than adults (e.g. that moderate or serious systemic symptoms were present in over 80% of the cases, which is a high number). This means that species causing mild cases in adults may cause more serious symptoms in adults.

Abstract:
Scorpion stings are a public health problem in Morocco, especially among children, who experience the most severe cases. Epidemiological and clinical findings on scorpion stings in Fez, Morocco, were evaluated in this investigation. Of 163 cases that required medical attention, 62.6% were male children. The mean age of patients was 4.8 ± 3.4 years. The mean time between stings and first medical attention was 3.36 ± 2.5 hours. Almost all cases occurred in the summer (94%) and extremities represented the most frequent sting sites (86.5%). Local pain, hyperemia, scarification, vomiting, sweating, restlessness, tachycardia and tachypnea were the observed clinical symptoms. Regarding severity, 55.2% of patients belonged to class III, followed by class II (26.4%) and class I (18.4%). None of our patients received antivenom; however, all of them were treated symptomatically depending on clinical manifestations.

Androctonus mauretanicus is probably the most medical significant species in Morocco, but members of the genus Buthus can also cause serious morbidity.

Reference:
Abourazzak S, Achour S, El Arqam L, Atmani S, Chaouki S, Semlali I, et al. Epidemiological and clinical characteristics of scorpion stings in children in Fez, Morocco. Journal of Venomous Animals and Toxins Including Tropical Diseases. 2009;15 (2):255-67

Water loss in scorpions living in arid environments

Scorpions are very common in many arid areas and many species are well adapted to a life in areas with high temperatures and low precipitation. One of the main adaptions to life in such harsh environments is to reduce loss of body water. Body water is lost to the environment mainly through the skin (cuticular water loss) and through respiration (respiratory water loss). In scorpions, the main loss of body water is through the respiration.

A recent study by Gefen, Ung & Gibbs (2009) looks into water loss in the North American species Hadrurus arizonensis (Caraboctonidae). See abstract for details about the study and its results.

Abstract:
Terrestrial arthropods lose body water to the environment mainly through transpiration. The aim of this study was to determine the fraction of respiratory losses from total transpiratory water loss in scorpions, as relatively high respiratory losses would indicate a fitness benefit from regulation of gas-exchange rate under stressful desiccating conditions. We measured metabolic rates and water-loss rates of Hadrurus arizonensis (Iuridae) at a range of ecologically-relevant temperatures. Calculation of respiratory water losses was based on increased metabolic and water-loss rates during nocturnal activity (assuming no change in cuticular resistance at a given constant experimental temperature). Respiratory losses accounted for 9.0 ± 1.7% of total transpiratory losses at 25 °C, doubled to 17.9 ± 1.8% at 30 °C and increased to 31.0 ± 2.0% at 35 °C (n = 5, 15 and 15, respectively). Furthermore, the relative importance of respiratory transpiration is likely to be higher at temperatures above 35 °C, which have been recorded even within the burrows of H. arizonensis. Measurements of cuticular lipid melting points do not provide evidence for increased cuticular resistance to water loss at higher temperatures. However, the relatively high fraction of respiratory water losses reported here for H. arizonensis supports the notion of respiratory regulation as an evolved mechanism for conserving scorpion body water stores under stressful conditions.

Reference:
Gefen E, Ung C, Gibbs AG. Partitioning of transpiratory water loss of the desert scorpion, Hadrurus arizonensis (Iuridae). J Insect Physiol. 2009 Jun;55 (6):544-8. [Subscription required for fulltext]

Family Caraboctonidae

A new fossil species in the genus Tityus from the Dominican Republic

A new species in the genus Tityus (Buthidae) has been described from a specimen in amber from the Dominican Republic.

Tityus hartkorni Lourenco, 2009 (Buthidae)

Abstract:
Tityus (Brazilotiyus) hartkorni sp. n., a new species of fossil scorpion belonging to the genus Tityus C. L. Koch and to the subgenus Brazilotityus Lourenço, is described from a specimen in amber from the Dominican Republic. The new species is clearly associated with the extant fauna of the Neotropical region. This discovery attests to a considerable degree of diversity in the Dominican amber-producing forests.

Please note that this species will not be listed in The Scorpion Files as I only list extant species.

Reference:
Lourenco WR. A new species of Tityus C. L. Koch, 1836 (subgenus Brazilotityus Lourenco, 2006) from the Dominican amber (Scorpiones: Buthidae). Euscorpius. 2009; (83):1-5. [Free fulltext]

Family Buthidae

A new species of Microtityus from Colombia

The genus Microtityus (Buthidae) is a group of small sized scorpions with a Neotropical distribution. Botero-Trujillo, Erazo-Moreno & Perez (2009) have now described a new species from Colombia:

Microtityus bivicentorum Botero-Trujillo, Erazo-Moreno & Perez, 2009 (Buthidae)

Abstract:
Microtityus bivicentorum sp. nov. is described based on two adult specimens of both sexes from a single locality near the city of Valledupar, northern Colombia. The new species is most similar to Microtityus desuzeae González-Sponga, 2001 and Microtityus joseantonioi González-Sponga, 1981 from Venezuela, and Microtityus franckei Botero-Trujillo & Noriega, 2008 from Colombia, with which it shares the absence of trichobothrium d2 on femur, Eb3 and Esb on pedipalp chela, and esb on fixed finger. With this description, the number of extant species of Microtityus is raised to 25, of which eleven are present in South America and two in Colombia. A map with the known distribution of M. bivicentorum sp. nov. and similar species is presented. Some remarks about the trichobothrial arrangement of M. joseantonioi are also included.

Reference:
Botero-Trujillo R, Erazo-Moreno MC, Perez GA. A new species of Microtityus Kjellesvig-Waering (Scorpiones: Buthidae) from northern Colombia. Zootaxa. 2009; (2120):27-38. [Subscription required for fulltext]

Family Buthidae