By Leena Khawar,Dr Muhammad Sohail Sajid
An ancient spider family, scorpions first emerged in the fossil record during the Silurian Period.
Eurypterids, enormous chelicerates that inhabited estuaries and coastal lagoons from the Ordovician Period to the Permian Period, are thought to be related by several arachnologists The fossilised Silurian and Devonian marine scorpions look strikingly like scorpions, except that scorpions are much smaller. 325 to 350 million years ago, arachnids walked onto land for the first time as air-breathing creatures. Scorpions have long piqued the interest of human cultures, with some considering them sacred and endowing them with special powers, while others regard them as dangerous and foreboding. There are several examples of scorpions in ancient cultures’ mythology and religious artefacts. These include representations on seals and magical tablets as well as amulets and boundary stones. Additionally, they were one of the 12 zodiac constellations, or signs, in Greek mythology. It is widely overestimated that scorpions are dangerously deadly despite the many prejudices and misconceptions about them that remain to this day. It is common knowledge that the majority of scorpions are not aggressive and inflict only slight, short-lived pain and discomfort when they sting. 40 to 50 species around the world, on the other hand, represent serious health threats. Human deaths can be caused by about 25 different species. Tropic and subtropical or desert regions of temperate zones are where most of them are found. Scorpion taxonomy has been unstable since the turn of this century. 1,077 species, 117 genera, and nine families of scorpions were listed by Sissom (1990) in his assessment of scorpion classification. More than 1,127 species of scorpions belong to the Buthidae family, which is the largest and most widespread among scorpion families. Although buthids can be found all over the planet, their variety is greatest in the Old World, particularly the Afrotropics and the southern Palaearctic. The majority of highly toxic scorpions are found in this family. ”
Morphology:
The prosoma (the phalothorax) and the opisthosoma (the abdomen) are the two major components of the scorpion body (abdomen). There are two distinct parts to the metasoma, one of which resembles the tail of a lizard (post-abdomen). In the back of the metasoma is a stinging structure known as the telson.
Ecology and Behaviour:
As a result of this, scorpions may thrive in a variety of environments, from deserts to grasslands to forests in both the temperate and tropical zones. It’s also worth noting that they can be found at sea level to 5,500 m above sea level, as well as in cave systems at depths of over 800 m. Their resistance to variations in temperature, cold, and even lengthy submersion in water is impressive, as is their ability to survive in harsh situations like famine and malnutrition for extended periods of time. There are many factors that contribute to these adaptations, such as behavioural thermoregulation and low metabolic rates, as well as great water conservation efficiency. When the scorpion’s body temperature rises, it retreats to the safety of burrows and other hidden areas during the daytime in order to cool off. While excreting nitrogenous wastes such as guanine, xanthine, and uric acid in virtually insoluble forms, they experience negligible water loss through their cuticle, spiracles, and book-lungs. Like their urine, their faeces are bone dry.
However, the big and important family Buthidae contains many species that can climb very well. Climbers include some of the most deadly scorpions, such as Centruroides scorpions. When it comes to food, scorpions prefer insects and spiders with soft bodies. Many spiders, including the solpugid and a variety of other species of scorpion as well as millipedes, centipede, gastropods, and other invertebrates, are common prey. In addition to lizards, snakes, and rodents, larger scorpions will hunt and eat other small vertebrates. Because of their limited vision, scorpions must rely on their sensory hairs and their capacity to detect ground vibrations in order to find, locate, and identify prey that is suitable for them to eat.
This is known as stilting, and it occurs when a pregnant female lifts the anterior half of her body and makes a birth basket with her pedipalps and the first two pairs of her legs.
Public Health Significance:
There are two sorts of reactions to a scorpion sting: localised, transient symptoms that last anywhere from a few minutes to a few hours, and systemic reactions. A wasp or bee sting is a good analogy for localised responses, which are characterised by acute pain and swelling at the sting site. It can take up to 72 hours for the swelling to subside, after which blood-filled blisters and haemorrhages appear near the sting site. Sloughing of the skin is possible, however the degree varies widely. Sweating and muscle cramps are some side symptoms that occur close to the sting location. Pain extends from the sting site up the affected limb in situations of buthid stings. The clinical signs and symptoms of systemic responses can range from moderate to life-threatening. Even minor systemic reactions are not always indicative of a significant disease. Swelling or skin darkening at the sting location is not always noticeable. It’s possible that an excruciating ache and burning could spread to nearby tissues, which will often throb and become numb as a result. Often, these systemic reactions last less than an hour and are not considered dangerous.
Neurologic effects might cause excessive sweating and salivation, restlessness, anxiousness, respiratory and cardiovascular issues, mental confusion, and even convulsions in more severe systemic reactions. Autonomic, sympathetic, and neuromuscular reactions have been observed in bee sting patients due to the toxin’s effects on these systems. Deaths from scorpion stings are most often attributed to heart failure. Respiratory failure, especially in patients with upper respiratory infections, may also be a factor. Envenomation frequently results in death within a few days. When symptoms lessen within the first 2-12 hours after a sting, there’s a significant chance of recovery. As far as medicinal importance goes, the Indian red scorpion is the most important scorpion in India.
Control and Prevention:
Pesticides are generally not suggested for controlling or preventing scorpions from entering houses. As an alternative, it is possible to adopt adequate steps to prevent scorpions from invading homes or to drastically minimise their chances of doing so. Raising the floor at least 20 centimetres above the ground will deter people from entering.
The near surroundings of residences can be deterred from attracting scorpions by cutting back vegetation that touches the building and eliminating heaps of firewood, lumber, bricks, and other objects that provide shelter. Protective netting around the bed provides comparable protection from mosquitoes. It is highly recommended that you shake out your clothes and shoes before wearing them. Sealing or barricading off entrance points is the only practicable way to prevent their entry.
Authors
Leena Khawar
(DVM, M.Phil. Parasitology)
University Of Agriculture Faisalabad
Dr Muhammad Sohail Sajid
Associate Professor, Department of Parasitology
University Of Agriculture Faisalabad