海底熱泉旁通常具有高濃度硫化氫釋放，而硫化氫會抑制生物的呼吸代謝，進而限制生物的生存。在此環境生存的生物，諸如深海熱泉中的螃蟹、貽貝、鬚腕類生物已知具備特殊的細胞解硫機制。然而，龜山島周遭的淺海熱泉組成，有別於典型的海底熱泉系統，在此區域棲息的硫磺怪方蟹(Xenograpsus testudinatus)對硫化物的耐受與適應機制，亦多屬推測並缺乏系統性的探討。
本論文研究目的旨在瞭解硫磺怪方蟹在其原生高硫環境是如何有效地進行硫化氫相關的解毒機制。實驗結果發現：怪方蟹血液具有亞磺酸(hypotaurine)與硫代牛磺酸(thiotaurine)的存在；在高硫環境中，怪方蟹第三、五對鰓的牛磺酸運輸蛋白(taurine transporter, TAUT，可運輸taurine、hypotaurine、thiotaurine)之表現量明顯高於無硫環境馴養的個體。以上結果皆暗示怪方蟹可能具備將S2-與hypotaurine代謝生合成thiotaurine，以降低硫毒性再進行運輸的適應能力。此外，本研究亦發現在原生高硫環境生存的怪方蟹鰓中，與硫運輸相關的表皮膜蛋白solute carrier family 26 member 11 (SLC26A11)基因與蛋白表現量均顯著高於無硫馴養的實驗個體。此結果暗示硫化氫氧化後形成毒性較低的硫酸根產物，可藉由鰓表皮細胞底膜的SLC26A11將硫酸根離子運輸至血液。根據以上結果我們推論：硫磺怪方蟹具有特殊的硫轉換機制，並在其鰓表皮上具有專一的硫相關運輸蛋白，可有效地降低生存在高硫環境中持續存在的毒性緊迫，以利在熱泉環境中生存。

The shallow-water hydrothermal vent system of Kueishan Island off the coast of Taiwan has been described as one of the most acidic vents in the world, discharging water with a high content of sulfur compounds. Sulfide is an inhibitor of cytochrome oxidase activity thus abolishes aerobic respiration. To survive in this toxic habitats, the vent crab, Xenograpsus testudinatus, may show a range of physiological feature to cope with sulfide-rich environment. In this study, we found the presence of hypotaurine and thiotaurine in the hemolymph, and transcript expressions of taurine transporter (taut) in the 3rd and 5th gill pair are significantly higher in native sulfidic environment than in non-sulfide treated seawater. Protein expression of TAUT in the 5th pair gill showed the similar appearance. These results inferred that X. testudinatus gills are capable to catabolize hypotaurine and S2- thus synthesize thiotaurine to reduce cellular toxicity. In addition, highly expressions of sulfur transport-related solute carrier 26A11 (SLC26A11), was found in gills of native habitants. It implies that sulfide may be oxidized to sulfate then transported by SLC26A11 in gill epithelium. Accordingly, X. testudinatus have evolved efficient sulfide detoxification mechanisms in gill epithelium to minimize sulfide-induced toxic stress under hydrothermal vent system.

Alper SL, Sharma AK. 2013. The SLC26 Gene Family of Anion Transporters and Channels. Molecular aspects of medicine 34:494-515.
Brand GL, Horak RV, Bris NL, Goffredi SK, Carney SL, Govenar B, Yancey PH. 2007. Hypotaurine and thiotaurine as indicators of sulfide exposure in bivalves and vestimentiferans from hydrothermal vents and cold seeps. Marine Ecology 28:208-218.
Cecile G, Helene L, Sandrine N, M.Sarradin P, C.Caprais J, Lallier FH. 1998. Determination of reduced sulfur compounds by high-performance liquid chromatography in hydrothermal seawater and body fluids from Riftia pachyptila. Analyst 123:1289-1293.
Chang CM. 2006. Sulfide tolerance and detoxification of the vent crab, Xenograpsus testudinatus. [thesis]. [Taipei, Taiwan]: National Taiwan University.
Chen CTA, Zeng Z, Kuo FW, Yang TF, Wang BJ, Tu YY. 2005. Tide-influenced acidic hydrothermal system offshore NE Taiwan. Chemical Geology 224:69-81.
DitteL AI, Perovich G, Epifanio CE. 2008. Biology of the Vent Crab Bythograea thermydron: A Brief Review. Journal of Shellfish Research 27:63-77.
Evans DH, Claiborne JB. 2005. The Physiology of Fishes, Third Edition. Boca Raton, FL: Taylor & Francis.
Freire CA, Onken H, McNamara JC. 2008. A structure–function analysis of ion transport in crustacean gills and excretory organs. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology 151:272-304.
Goffredi S, Childress J, Desaulniers N, Lee R, Lallier F, Hammond D. 1997. Inorganic carbon acquisition by the hydrothermal vent tubeworm Riftia pachyptila depends upon high external pCO2 and upon proton-equivalent ion transport by the worm. The Journal of Experimental Biology 200:883-896.
Goffredi SK. 2010. Indigenous ectosymbiotic bacteria associated with diverse hydrothermal vent invertebrates. Environmental Microbiology Reports 2:479-488.
Gorodezky LA, Childress JJ. 1994. Effects of sulfide exposure history and hemolymph thiosulfate on oxygen-consumption rates and regulation in the hydrothermal vent crab Bythograea thermydron. Marine Biology 120:123-131.
Hügler M, Petersen JM, Dubilier N, Imhoff JF, Sievert SM. 2011. Pathways of Carbon and Energy Metabolism of the Epibiotic Community Associated with the Deep-Sea Hydrothermal Vent Shrimp Rimicaris exoculata. PLOS ONE 6:e16018.
Henry R, Lucu C, Onken H, Weihrauch D. 2012. Multiple functions of the crustacean gill: osmotic/ionic regulation, acid-base balance, ammonia excretion, and bioaccumulation of toxic metals. Frontiers in Physiology 3.
Hu MY, Guh YJ, Shao YT, Kuan PL, Chen GL, Lee JR, Jeng MS, Tseng YC. 2016. Strong Ion Regulatory Abilities Enable the Crab Xenograpsus testudinatus to Inhabit Highly Acidified Marine Vent Systems. Frontiers in Physiology 7:14.
Hwang JS, Dahms HU, Alekseev V. 2008. Novel nursery habitat of hydrothermal vent crabs. Crustaceana 81:375-380.
Inoue K, Tsukuda K, Koito T, Miyazaki Y, Hosoi M, Kado R, Miyazaki N, Toyohara H. 2008. Possible role of a taurine transporter in the deep‐sea mussel Bathymodiolus septemdierum in adaptation to hydrothermal vents. FEBS letters 582:1542-1546.
Kelley JL, Arias-Rodriguez L, Patacsil Martin D, Yee MC, Bustamante CD, Tobler M. 2016. Mechanisms Underlying Adaptation to Life in Hydrogen Sulfide–Rich Environments. Molecular Biology and Evolution 33:1419-1434.
Koito T, Morimoto S, Toyohara H, Yoshida T, Jimbo M, Maruyama T, Miyazaki N, Inoue K. 2010. Decline in taurine transporter mRNA and thioautotrophic bacterial 16S rDNA levels after transplantation of the hydrothermal-vent mussel Bathymodiolus septemdierum to a non-vent position. CAHIERS DE BIOLOGIE MARINE 51:429-434.
Lee A, Beck L, Markovich D. 2000. The Human Renal Sodium Sulfate Cotransporter (SLC13A1; hNaSi-1) cDNA and Gene: Organization, Chromosomal Localization, and Functional Characterization. Genomics 70:354-363.
Markl J, Decker H. 1992. Molecular structure of the arthropod hemocyanins. In. Blood and tissue oxygen carriers: Springer. p. 325-376.
Markovich D. 2012. Slc13a1 and Slc26a1 KO Models Reveal Physiological Roles of Anion Transporters. Physiology 27:7-14.
Mateos M, Hurtado LA, Santamaria CA, Leignel V, Guinot D. 2012. Molecular Systematics of the Deep-Sea Hydrothermal Vent Endemic Brachyuran Family Bythograeidae: A Comparison of Three Bayesian Species Tree Methods. PLOS ONE 7:e32066.
Morri C, Bianchi CN, Cocito S, Peirano A, Biase AMD, Aliani S, Pansini M, Boyer M, Ferdeghini F, Pestarino M, et al. (Morri1999 co-authors). 1999. Biodiversity of marine sessile epifauna at an Aegean island subject to hydrothermal activity: Milos, eastern Mediterranean Sea. Marine Biology 135:729-739.
Nakamura-Kusakabe I, Nagasaki T, Kinjo A, Sassa M, Koito T, Okamura K, Yamagami S, Yamanaka T, Tsuchida S, Inoue K. 2016. Effect of sulfide, osmotic, and thermal stresses on taurine transporter mRNA levels in the gills of the hydrothermal vent-specific mussel Bathymodiolus septemdierum. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology 191:74-79.
Ng NK, Davie PJF, Schubart CD, Ng PKL. 2007. Xenograpsidae, a new family of grapsoid crabs (Crustacea: Brachyura) associated with shallow water hydrothermal vents. The Raffles Bulletin of Zoology 16:233-256.
Ng NK, Huang JF, Ho PH. 2000. Description of a new species of hydrothermal crab, Xenograpsus testudinatus (Crustacea: Decapoda: Brachyura: Grapsidae) from Taiwan. National Taiwan Museum Special Publication Series No. 10:191-199.
Nicholls P, Kim JK. 1982. Sulphide as an inhibitor and electron donor for the cytochrome c oxidase system. Canadian journal of biochemistry 60:613-623.
Olson KR, Straub KD. 2016. The Role of Hydrogen Sulfide in Evolution and the Evolution of Hydrogen Sulfide in Metabolism and Signaling. Physiology 31:60-72.
Ponsard J, Cambon-Bonavita M-A, Zbinden M, Lepoint G, Joassin A, Corbari L, Shillito B, Durand L, Cueff-Gauchard V, Compère P. 2013. Inorganic carbon fixation by chemosynthetic ectosymbionts and nutritional transfers to the hydrothermal vent host-shrimp Rimicaris exoculata. The ISME Journal 7:96-109.
Pruski AM, Aline FM. 2003. Stimulatory effect of sulphide on thiotaurine synthesis in three hydrothermal-vent species from the East Pacific Rise. Journal of experimental biology 206:2923-2930.
Pruski AM, De Wit R, Fiala-Médioni A. 2001. Carrier of reduced sulfur is a possible role for thiotaurine in symbiotic species from hydrothermal vents with thiotrophic symbionts. Hydrobiologia 461:15-23.
Pruski AM, Médioni AF, Prodon R, Colomines JC. 2000. Thiotaurine is a biomarker of sulfide‐based symbiosis in deep‐sea bivalves. Limnology and Oceanography 45:1860-1867.
Sanglier S, Leize E, Dorsselaer AV, Zal F. 2003. Comparative ESI-MS study of∼ 2.2 MDa native hemocyanins from deep-sea and shore crabs: from protein oligomeric state to biotope. Journal of the American Society for Mass Spectrometry 14:419-429.
Tarasov VG, Gebruk AV, Mironov AN, Moskalev LI. 2005. Deep-sea and shallow-water hydrothermal vent communities: Two different phenomena? Chemical Geology 224:5-39.
Thimgan MS, Berg JS, Stuart AE. 2006. Comparative sequence analysis and tissue localization of members of the SLC6 family of transporters in adult Drosophila melanogaster. Journal of experimental biology 209:3383-3404.
Tobler M, Henpita C, Bassett B, Kelley JL, Shaw JH. 2014. H2S exposure elicits differential expression of candidate genes in fish adapted to sulfidic and non-sulfidic environments. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology 175:7-14.
Vetter RD, Wells ME, Kurtsman AL, Somero GN. 1987. Sulfide detoxification by the hydrothermal vent crab Bythograea thermydron and other decapod crustaceans. Physiological Zoology 60:121-137.
Vincourt J-B, Jullien D, Amalric F, Girard J-P. 2003. Molecular and functional characterization of SLC26A11, a sodium-independent sulfate transporter from high endothelial venules. The FASEB Journal 17:890-892.
Vismann B. 1991. Sulfide tolerance: Physiological mechanisms and ecological implications. Ophelia 34:1-27.
Yang SH, Chiang PW, Hsu TC, Kao SJ, Tang SL. 2016. Bacterial Community Associated with Organs of Shallow Hydrothermal Vent Crab Xenograpsus testudinatus near Kuishan Island, Taiwan. PLOS ONE 11(3): e0150597.