maenas (intertidal zone) and Segonzacia mesatlantica - Station ...

More documents

Recommendations

Info

204 CHAPITRE 5. ADAPTATIONS RESPIRATOIRES DE S. MESATLANTICA TAB. 5.3 – Comparison of composition of sea water, hydrothermal fluid and hemolymph from various decapod species. Values are mean ± s.d. Species Group Location Na+ (mM) K+ (mM) Ca 2+ (mM) Mg 2+ (mM) S. mesatlantica a Brachyura Hydroth. vent 491 ± 33 10.7 ± 1.6 13 ± 1.1 23 ± 4 C. praedator a Brachyura Hydroth. vent 479.6 ± 43.7 8.7 ± 2.2 14.9 ± 6.2 21.6 ± 9.3 B. thermydron a Brachyura Hydroth. vent 431.6 ± 73.4 6.9 ± 1.7 9.3 ± 4.5 19 ± 9.6 R. exoculata a Caridea Hydroth. vent 403.4 ± 37.4 5.4 ± 1.1 4.6 ± 1.5 14.2 ± 6.4 C. chacei a Caridea Hydroth. vent 451.8 ± 1.2 9.6 ± 0.8 4.8 ± 1 6.2 ± 0.7 M. fortunata a Caridea Hydroth. vent 518 10.8 17.9 11 C. affinis a Brachyura Deep sea 504.8 ± 19.2 8.8 ± 0.7 14.8 ± 4.6 19.5 ± 2.1 C. maenas Brachyura Shallow water 506.8 ± 16.9 b 9.07 ±0.83 b 26 c 16.2-21.5 d -40 c Hydrothermal fluid (Lucky Strike) e 390 23.4 35.6 0 Standard deep-sea water e 468 10.2 10.3 52.9 Mix (10 % fluid for a 27°C mix) f 460.2 11.52 12.83 47.61 a Chausson (2001) b personal data c Truchot (1975) d Tentori et Lockwood (1990) e Charlou et al. (2000) f Chausson et al. (2004) 5.4.4 Discussion Hemolymph composition The measured inorganic ions concentrations show that S. mesatlantica hemolymph is almost isotonic to the surrounding sea water, except for Mg 2+ for which it is hypotonic. No particular difference is observed compared to other hydrothermal and deep-sea species and to shallow water crab species, except for the magnesium content which is generally lower in hydrothermal brachyurans compared to shallow water ones (Table 5.3). For Bythograea thermydron, a strong hyporegulation of Mg 2+ was observed over a large range of salinities (Martinez et al., 2001). Mg 2+ is an inhibitor of the neuromuscular activity in crustaceans (Katz, 1936) and a negative correlation between general level of activity and hemolymph Mg 2+ concentration has been observed in brachyuran crustaceans (Robertson, 1953). The lower Mg 2+ level in hydrothermal vent crustaceans is close to the level in the more active crabs such as C. maenas and P. marmoratus (Martinez et al., 2001) and is interpretable as a way to perform faster and more important locomotive activity in an environment in which rapid fluctuations can occur and force animals to move rapidly in response to a sudden stress (Chausson, 2001, Thiberge, 2006). Thus, the proximity to the vent source does not induce marked modification of hemolymph inorganic ion composition and hypo-regulation of Mg 2+ can be associated with the necessity for rapid locomotory responses. The animals experience rapid fluctuations of salinities when foraging in the mixing
5.4. MANUSCRIT : RESPIRATORY ADAPTATIONS OF S. MESATLANTICA 205 zone and the average experienced ionic concentrations must be quite close to those of deep-sea water on the whole. Measured organic ions levels are high compared to shallow water species. The observed range for L-lactate concentration is similar to those for other decapods, but a high basal level is evidenced by the average value of 4 mM even in normoxia acclimations. This indicates that a basal level of anaerobic metabolism may be triggered at all times in S. mesatlantica. Values of 5.57 ± 1.07 mM lactate were recorded for freshly caught B. thermydron and 3.47 ± 0.5 mM in 24-48h maintained individuals (Sanders et Childress, 1992), showing that high basal levels of lactate are found also for this hydrothermal vent crab. The maximum observed value of 12 mM for S. mesatlantica is inferior to the 31.1 mM found in hypoxic B. thermydron (Chausson, 2001), but this could be due to a hypoxia not severe enough in our study. Higher levels could possibly be detected in tougher conditions. For urate levels, a very high variability was observed between individuals. Urate levels measured in hydrothermal vent crustaceans are generally high. The highest values measured here are well above those observed for shallow water species and were always found in acclimated crabs, whatever the condition was. Urate is a typical modulator present under stress in decapods (Bridges, 2001) ; the urate response to acclimation indicates that the repressurization process in itself can be a stress, maybe due to the rapid rise of pressure. This calls for control experiments with progressive increase of the pressure. The hemolymph protein content is high for S. mesatlantica, as observed for other hydrothermal crustacean species. This results in a higher oxyphoric capacity of the blood since hemocyanin is the main protein present, as in other brachyurans/decapods. For an average value of 117 µg/µl Hc for S. mesatlantica, the oxyphoric capacity is 1.56 mM O 2 compared to 0.97 mM O 2 for Carcinus maenas (average value of 73 µg/µl Hc for 32 individuals, personal observation). A very high variabwility was observed between individuals as in other species. The hemocyanin content is in contradiction with previous results from Chausson (Chausson et al., 2004). In this study, a high protein concentration was also observed but only 30 % of protein was identified as hemocyanin. Our results are in accordance with the protein content but not on the hemocyanin content. Since the authors could not detect other protein by FPLC, we hypothesize that the difference comes from the determination of hemocyanin content in the previous study. Hemocyanin structure As previously described by Chausson and Sanglier (Sanglier et al., 2003, Chausson et al., 2004), S. mesatlantica presents a typical decapod hemocyanin structure comprised mainly of dodecamers and hexamers of ˜75 kDa subunits. The subunit diversity observed here is higher than previously described with 8 major subunits and 8 minor subunits detected by denaturing ESI-MS. Only 4 subunits
Page 1 and 2:
THESE DE DOCTORAT DE L’UNIVERSITE
Page 3:
i Résumé / Abstract Réponse adap
Page 6 and 7:
iv SOMMAIRE 4.2 Objectifs de l’é
Page 8 and 9:
2 CHAPITRE 1. INTRODUCTION Les éco
Page 10 and 11:
4 CHAPITRE 1. INTRODUCTION 1.1 Mili
Page 12 and 13:
6 CHAPITRE 1. INTRODUCTION Les prin
Page 14 and 15:
8 CHAPITRE 1. INTRODUCTION TAB. 1.1
Page 16 and 17:
10 CHAPITRE 1. INTRODUCTION et cycl
Page 18 and 19:
FIG. 1.5 - Localisation des princip
Page 20 and 21:
(a) FIG. 1.6 - Fonctionnement d’u
Page 22 and 23:
16 CHAPITRE 1. INTRODUCTION TAB. 1.
Page 24 and 25:
18 CHAPITRE 1. INTRODUCTION FIG. 1.
Page 26 and 27:
20 CHAPITRE 1. INTRODUCTION Différ
Page 28 and 29:
Page 30 and 31:
24 CHAPITRE 1. INTRODUCTION le mili
Page 32 and 33:
26 CHAPITRE 1. INTRODUCTION Capacit
Page 34 and 35:
28 CHAPITRE 1. INTRODUCTION TAB. 1.
Page 36 and 37:
30 CHAPITRE 1. INTRODUCTION 700 600
Page 38 and 39:
32 CHAPITRE 1. INTRODUCTION férent
Page 40 and 41:
34 CHAPITRE 1. INTRODUCTION (a) (b)
Page 42 and 43:
Page 44 and 45:
Page 46 and 47:
40 CHAPITRE 1. INTRODUCTION 1 P 50
Page 48 and 49:
42 CHAPITRE 1. INTRODUCTION presque
Page 50 and 51:
44 CHAPITRE 1. INTRODUCTION affecte
Page 52 and 53:
Page 54 and 55:
Page 56 and 57:
50 CHAPITRE 1. INTRODUCTION fure co
Page 58 and 59:
52 CHAPITRE 1. INTRODUCTION amélio
Page 60 and 61:
54 CHAPITRE 1. INTRODUCTION 1.5 Que
Page 62 and 63:
56 CHAPITRE 2. ESI-MS ET MALLS APPL
Page 64 and 65:
Page 66 and 67:
Page 68 and 69:
Page 70 and 71:
Page 72 and 73:
Page 74 and 75:
Page 76 and 77:
Page 78 and 79:
The Structural Analysis of Large No
Page 80 and 81:
Page 82 and 83:
Page 84 and 85:
Page 86 and 87:
Page 88 and 89:
Page 90 and 91:
Page 92 and 93:
Page 94 and 95:
Page 96 and 97:
Page 98 and 99:
Page 100 and 101:
Page 102 and 103:
Page 104 and 105:
Page 106 and 107:
Page 108 and 109:
102 CHAPITRE 2. ESI-MS ET MALLS APP
Page 110 and 111:
104 CHAPITRE 3. STRUCTURE DE L’HC
Page 112 and 113:
Page 114 and 115:
Page 116 and 117:
Page 118 and 119:
Page 120 and 121:
Page 122 and 123:
Page 124 and 125:
Page 126 and 127:
Page 128 and 129:
Page 130 and 131:
Page 132 and 133:
Page 134 and 135:
Page 136 and 137:
Page 138 and 139:
Page 140 and 141:
134 CHAPITRE 4. PLASTICITÉ PHÉNOT
Page 142 and 143:
Page 144 and 145:
Page 146 and 147:
Page 148 and 149:
Page 150 and 151:
Page 152 and 153:
Page 154 and 155:
Page 156 and 157:
Page 158 and 159:
Page 160 and 161: 154 CHAPITRE 4. PLASTICITÉ PHÉNOT
Page 172 and 173: Dénaturant Natif
Page 178 and 179: 172 CHAPITRE 5. ADAPTATIONS RESPIRA
Page 222 and 223: 216 CHAPITRE 6. CONCLUSION ET PERSP
Page 233 and 234: Annexe A Détermination des masses
Page 235 and 236: 229 10000 h280 .M h) h280−h337 80
Page 237 and 238: Annexe B Détermination des distrib
Page 239 and 240: 233 Modèle 2 : 2 sous-unités lég
Page 241 and 242: 235 1 0.9 0.8 6 s-u aléatoires 2 s
Page 243 and 244: Bibliographie Adair, G. S. The hemo
Page 245 and 246: BIBLIOGRAPHIE 239 Catalina, M. I.,
Page 247 and 248: BIBLIOGRAPHIE 241 Farmer, C. S., J.
Page 249 and 250: BIBLIOGRAPHIE 243 Hourdez, S. Adapt
Page 251 and 252: BIBLIOGRAPHIE 245 Mangum, C. P. Sub
Page 253 and 254: BIBLIOGRAPHIE 247 Rainer, J., C. P.
Page 255 and 256: BIBLIOGRAPHIE 249 Svedberg, T. et I
Page 257 and 258: BIBLIOGRAPHIE 251 Vanin, S., E. Neg
Page 259 and 260: Liste des figures 1.1 Cycle des mar
Page 261:
LISTE DES FIGURES 255 4.17 Profils
Page 265 and 266:
Table des matières Résumé Sommai
Page 267 and 268:
TABLE DES MATIÈRES 261 4.3.5 Spect
Page 269 and 270:
TABLE DES MATIÈRES 263 Table des m
show all

maenas (intertidal zone) and Segonzacia mesatlantica - Station ...

Create successful ePaper yourself

Delete template?

Save as template?