Photoreceptor physiology of two species of crab spiders (Araneae: Thomisidae)

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  Photoreceptor physiology of two species of crab spiders (Araneae: Thomisidae) Abstract Spiders are a diverse order of predatory arachnids with more than 53.000 described species, most of which have eight eyes. Many webless hunting spiders, most noticeably the jumping spiders (Salticidae) have been shown to have excellent eyes with high spatial resolution and colour vision. The family of crab spiders (Thomisidae) is also hypothesized to be visual hunters, employing a “sit and wait” or ambush hunting technique; however, little is currently known about their visual capacity. Here we use extracellular electrophysiology to examine the photoreceptor physiology of two crab spiders living in two different ecological niches.  Ozyptila praticola  (C.L. Koch, 1837) hunts on the ground in dim habitats whereas  Xysticus cristatus  (Clerck, 1757) hunts in the typical bright open grasslands. We test the hypotheses that (1) each species has special-purpose eyes, (2) that male...

Epidemiology of scorpion sting and snakebite cases in Qatar 2018-2022: A primary care-based study

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 Epidemiology of scorpion sting and snakebite cases in Qatar 2018-2022: A primary care-based study

ABSTRACT

Background: Envenomation caused by snakebites and scorpion stings is a neglected disease responsible for significant morbidity and mortality. In Qatar, little information is available on the epidemiological aspects of snakebites and scorpion stings. This study describes the demographic and epidemiological characteristics of patients treated for scorpion stings or snakebites at Qatar’s Primary Health Care Corporation (PHCC).

Methods: A retrospective data analysis was applied to investigate the number of scorpion stings and snakebites reported at the PHCC health centers between January 1, 2018, and December 31, 2022. The data were electronically extracted from the medical records of the registered population at PHCC.

Results: 581 scorpion stings and 21 cases of snakebites were reported between January 1, 2018, and December 31, 2022. The highest number of scorpion stings reported in 2020 was 141 cases. The distribution of scorpion stings was higher among males than females, with rates of 86% and 14%, respectively, and the highest number of cases occurred in the age group of 19–39 years. Among the total cases, Bangladeshi and Qatari were the most affected, with a rate of 41% and 14%, respectively. The western region had the highest incidence of scorpion stings, at 7.47 per 10,000 persons.

Conclusion: According to this research, the western region had the highest occurrence of scorpion stings cases, primarily among Bangladeshis and Qataris, particularly in the age group of 19–49 years. This study also found similar patterns in snakebite cases. Consequently, this study emphasizes the need for increased investment in antivenom and the training of healthcare professionals to address scorpion stings effectively.

Al-Kuwari, Mohamed & Bakri, Ahmad & Kandy, Mujeeb & Illiayaraja, Jeyaram & Abdulmajeed, Jazeel & Al-Abdulla, Yousef. (2023). Epidemiology of scorpion sting and snakebite cases in Qatar 2018-2022: A primary care-based study. Journal of Emergency Medicine, Trauma and Acute Care. 2023. 26. 10.5339/jemtac.2023.26.