Physiological adaptions in winter active species of Urophonius

 

Scorpions are mainly known from warm regions and their adaptions to arid habitats are well studied. Less known and studied are scorpions that inhabit high altitudes or other habitats that experience sub-zero temperatures during the year. A special case among these are the two species Urophonius achalensis Abalos & Hominal, 1974 and U. brachycentrus (Thorell, 1876) (Bothriuridae) from Argentina that are unusual in that they actually are active during the winter (in periods with sub-zero temperatures).

C.Fernando Garcia and co-workers published last year a study investigating the possible physiological adaptations to different temperatures in the two winter active bothriurids. Their main conclusion is that the acclimatization to cold generates important lipidic metabolic variations in different organs and tissues.

Abstract:
Different organisms (mainly poikilotherms) are subject to environmental fluctuations that could affect their normal physiological functioning (e.g., by destabilization of biomembranes and rupture of biomolecules). As a result, animals regulate their body temperature and adapt to different environmental conditions through various physiological strategies. These adaptations are crucial in all organisms, although they are more relevant in those that have reached a great adaptive diversity such as scorpions. Within scorpions, the genus Urophonius presents species with winter activity, being this a peculiarity within the Order and an opportunity to study the strategies deployed by these organisms when facing different temperatures. Here, we explore three basic issues of lipid remodeling under high and low temperatures, using adults and juveniles of Urophonius achalensis and U. brachycentrus. First, as an indicator of metabolic state, we analyzed the lipidic changes in different tissues observing that low temperatures generate higher quantities of triacylglycerols and fewer amount of structural lipids and sphyngomielin. Furthermore, we studied the participation of fatty acids in adaptive homeoviscosity, showing that there are changes in the quantity of saturated and unsaturated fatty acids at low temperature (mainly 16:0, 18:0, 18:1 and 18:2). Finally, we observe that there are quantitative and qualitative variations in the cuticular hydrocarbons (with possible water barrier and chemical recognition function). These fluctuations are in some cases species-specific, metabolic-specific, tissue-specific and in others depend on the ontogenetic state.

Reference:
Garcia CF, Oviedo-Diego M, Laino A, Peterson G, Mattoni CI, Peretti AV, et al. Low temperatures induce physiological changes in lipids, fatty acids and hydrocarbons, in two rare winter scorpions of genus Urophonius (Scorpiones, Bothriuridae). J Therm Biol. 2021;96. [Sunscription required for full text]

Thanks to Andres Ojanguren-Affilastro for sending me their article!