22 June, 2016

Similarities in scorpion burrows imply similar function

Amanda Adams and co-workers have recently published an analysis of the burrow structures of three scorpion species in the family Scorpionidae (Scorpio palmatus (Ehrenberg, 1829) from Israel and Opistophthalmus setifrons Lawrence, 1961 and O. wahlbergii Thorell, 1876 from Namibia).

The following similar architectural structures of burrows were found for all three species:

1. Just below the entrance, all species had a horizontal platform.

2. All three species had at least two bends of the vertical tunnel going down.

3. The burrows of all species ended in an enlarged terminal chamber (usually larger for female occupants).

The article concludes that the similarity of the burrow structure has a common goal of managing the scorpions physical environment (keeping temperature and humidity stable and optimal) and providing protection from predators and cannibalistic conspecifics.

This is an interesting and readable article for those of you interested in scorpion ecology and scorpions adaption to their environment.

Many animals reside in burrows that may serve as refuges from predators and adverse environmental conditions. Burrow design varies widely among and within taxa, and these structures are adaptive, fulfilling physiological (and other) functions. We examined the burrow architecture of three scorpion species of the family Scorpionidae: Scorpio palmatus from the Negev desert, Israel; Opistophthalmus setifrons, from the Central Highlands, Namibia; and Opistophthalmus wahlbergii from the Kalahari desert, Namibia. We hypothesized that burrow structure maintains temperature and soil moisture conditions optimal for the behavior and physiology of the scorpion. Casts of burrows, poured in situ with molten aluminum, were scanned in 3D to quantify burrow structure. Three architectural features were common to the burrows of all species: (1) a horizontal platform near the ground surface, long enough to accommodate the scorpion, located just below the entrance, 2–5 cm under the surface, which may provide a safe place where the scorpion can monitor the presence of potential prey, predators, and mates and where the scorpion warms up before foraging; (2) at least two bends that might deter incursion by predators andmay reduce convective ventilation, thereby maintaining relatively high humidity and low temperature; and (3) an enlarged terminal chamber to a depth at which temperatures are almost constant (±2–4 °C). These common features among the burrows of three different species suggest that they are important for regulating the physical environment of their inhabitants and that burrows are part of scorpions’ Bextended physiology^ (sensu Turner, Physiol Biochem Zool 74:798–822, 2000).

Adams AM, Marais E, Turner JS, Prendini L, Pinshow B. Similar burrow architecture of three arid-zone scorpion species implies similar ecological function. The Science of Nature. 2016;103(7):1-11.[Subscription required for full text]

See also: Scorpions have similar tastes in burrow architecture

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