Specialized adaptations allow vent-endemic crabs (Xenograpsus testudinatus) to thrive under extreme environmental hypercapnia
| Autor: | Alex R. Quijada-Rodriguez, Dirk Weihrauch, Pung-Pung Hwang, Yung Che Tseng, Pou Long Kuan, Garett J. P. Allen |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
Brachyura lcsh:Medicine Kidney 010603 evolutionary biology 01 natural sciences Article Hypercapnia Stress Physiological Hemolymph Animals Xenograpsus testudinatus lcsh:Science Multidisciplinary Chemistry 010604 marine biology & hydrobiology Respiration lcsh:R Environmental Exposure Hydrogen-Ion Concentration Adaptation Physiological Crystallography Physiological Adaptations lcsh:Q WHOLE ANIMAL Hydrothermal vent |
| Zdroj: | Scientific Reports Scientific Reports, Vol 10, Iss 1, Pp 1-13 (2020) |
| ISSN: | 2045-2322 |
| Popis: | Shallow hydrothermal vent environments are typically very warm and acidic due to the mixing of ambient seawater with volcanic gasses (> 92% CO2) released through the seafloor making them potential ‘natural laboratories’ to study long-term adaptations to extreme hypercapnic conditions. Xenograpsus testudinatus, the shallow hydrothermal vent crab, is the sole metazoan inhabitant endemic to vents surrounding Kueishantao Island, Taiwan, where it inhabits waters that are generally pH 6.50 with maximum acidities reported as pH 5.50. This study assessed the acid–base regulatory capacity and the compensatory response of X. testudinatus to investigate its remarkable physiological adaptations. Hemolymph parameters (pH, [HCO3−], $${\text{P}}_{{{\text{CO}}_{2} }}$$PCO2, [NH4+], and major ion compositions) and the whole animal’s rates of oxygen consumption and ammonia excretion were measured throughout a 14-day acclimation to pH 6.5 and 5.5. Data revealed that vent crabs are exceptionally strong acid–base regulators capable of maintaining homeostatic pH against extreme hypercapnia (pH 5.50, 24.6 kPa $${\text{P}}_{{{\text{CO}}_{2} }}$$PCO2) via HCO3−/Cl− exchange, retention and utilization of extracellular ammonia. Intact crabs as well as their isolated perfused gills maintained $${\text{P}}_{{{\text{CO}}_{2} }}$$PCO2tensions below environmental levels suggesting the gills can excrete CO2 against a hemolymph-directed $${\text{P}}_{{{\text{CO}}_{2} }}$$PCO2 gradient. These specialized physiological mechanisms may be amongst the adaptations required by vent-endemic animals surviving in extreme conditions. |
| Databáze: | OpenAIRE |
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