32 Roselly de Lourges, *Cristoforo Colombo, Storia della sua vita*.

33 See § 3.8.

34 See § 6.9.

35 Such errors constitute a serious problem that were common in the period, so much so that in his great work on pure and applied mathematics, *General Trattato di Numeri et Misure* (1556- 60), Tartaglia felt it necessary to dedicate an entire chapter to the way in which numbers should

However, Navarrete had already formulated his condemnation of Vespucci in the Prologue to Volume III where he wrote,

The second Section contains the reports on the four journeys that it is presumed Amerigo Vespucci undertook, which were not published in Spain but rather in a hidden and cunning manner in various places in Europe (while the family of Columbus was on the island of San Domingo), succeeding in calling the new continent by a name that did not belong to it [...]; the artful caution with which the reports spread through foreign countries, always avoiding appearing in Spain and Portugal where it was not so easy to hide the truth: and later neither court sentences nor the force of the law were enough to remove the name *America* from the part of the world discovered by Christopher Columbus and the Spaniards who followed him in such an audacious and dangerous endeavour.36

No authentic substantial facts are cited in this severe accusation, while the fact that Columbus knew about Amerigo's third voyage and that its merits went unrecognised is ignored. Moreover, Navarrete held Vespucci responsible for what was published in Europe about his travels, but it would not have been difficult for him to ascertain that the *Mundus Novus* was published in faraway places and without Vespucci's knowledge, as he was on his fourth voyage at the time. Besides, King Manuel and the Spanish sovereigns had certainly been informed about these publications by their diplomats. Navarrete also ignored the fact that Amerigo had become a Spanish citizen, a citizen of the country whose values he meant to defend.

One can understand the distress of an erudite and patriotic man like Navarrete, writing at the time of the restoration following Napoleon Bonaparte's tyrannical seizure of power in Spain. One can understand the desolation of a man contemplating the ruin of his own country, from which the overseas colonies had just separated, and easily understand why he wished to glorify a distant period of wealth and power, wounded by a presumed usurpation. What one cannot understand are those who insist in wrongly denigrating Amerigo Vespucci, a man of great merits, with accusations that are easily disproven.

be written. In Amerigo's writings, this question is often extremely complicated, even though a source of ambiguities can be identified in the fact that the number 4, if not accompanied by other Arabic numbers, can often be mistaken for the Roman numeral X. For this reason, 4 is read as ten and 44 read as twenty: mine is a modest corrective for a multitude of errors.

36 "La Seccion II contiene las relaciones de los cuatro viages que supone haber hecho Américo Vespucio; las cuales nunca se han impreso en España; pero divulgadas oculta y artificiosamente por Europa (miéntrasla familia de los Colones residia en la isla de Santo Domingo) lograron apellidar al nuevo continente con un nombre que no le correspondia [...] la cautela artificiosa con que se propagaban por paises extrangeros, huyendo siempre de aparecer en España y Portugal donde no era tan fácil ocultar la verdad; ni en tiempos posteriores las sentencias judiciales ni la fuerza de las leyes, hayan bastado á privar del nombre de *América* a la parte del mundo que descubrió Don Cristóbal Colon y los españoles que le siguieron e imitaron en tan árdua y peligrosa carrera".

### 15 Epilogue (1515-1521)

Aphonso de Albuquerche was for some time in charge of a part of Tristan da Cunha's large fleet, but he soon became an independent captain and contributed to the knowledge of Asia as a daring sailor and soldier. He was the first European to have sailed his ships into the Red Sea and establish contact with the Negus of Abyssinia. He reached and explored the Persian Gulf, a mythical place that for many centuries had been unreachable. He consolidated the tenure of the base of Goa on the west coast of the Indian peninsula, modelling it in his own way; from there he went further to the east, taking possession of the Malacca, the peninsula that juts out towards the Equator. As a soldier he was bold, but often cruel and ruthless; at the same time, he was a skilled and clever diplomat. Having reached Canton in southern China he established trade contacts with the great Ming empire. The year was 1513.

He was named Governor of Portuguese India. He went south of Malaysia to the mythical islands of Sumatra and Java, in short, great swathes of Asia opened up before the man who was now aiming for the Spice Islands. But when he returned to the base of Goa in December 1515, he had a terrible news waiting for him: King Manuel had deprived him of the office of Governor, giving his command to a rival of his, Lopo Soares de Albergaria.

Feeling destroyed, Albuquerque wrote a memorial in which he assured the King of his loyalty, asked clemency for his son Brás who had helped him with great courage, and begged the King to transfer all the honours and rewards that were due to himself to Brás and a little later, on December 16, he died of a broken heart.

On January 23, 1516, King Ferdinand of Aragon died. In his will he had ordered that Cardinal Jiménez de Cisneros should assume the office of regent. The cardinal carefully arranged for the succession of Carlos of Habsburg, grandson of Ferdinand and of Maximilian I, Emperor of the Holy Roman Empire, and Carlos in September 1517 became King Carlos I of the whole of Spain at the age of 17.

The very young ruler neglected to summon the *Cortes* to legitimise his access to the throne, and apparently he took his mother Queen Juana from the convent – a prison in which she had been locked up; he had not seen her since he was seven.

**Figure 15.1** A hundred years after the success of Christopher Columbus, in this representation of the Earth's surface (1592) divided into two hemispheres, Levius Hulsius has placed six medallions in which he shows the principal discoverers of the New World: Columbus, Vespucci, Magellan and the three men who circumnavigated the world, Juan Sebastián Elcano, Francis Drake and Thomas Cavendish

Carlos I became familiar with his royal duties, and soon gave orders to the *Casa de la Contratación* to resume the organisation of a fleet that would reach the mythical Moluccas, which were rich in many treasures. He had heard about them during his adolescence, and he knew that his parents had taken care of the project. The urge to restart the trip was given, probably, both by his mother and by two people who had left Portugal following disagreements with King Manuel, who as he aged became increasingly bitter with his subjects and closed with his secrets: the cosmographer and astronomer Ruy Faleiro and Ferdinand Magellan. The Fugger bank said it was ready to participate in the financing of the project.

Resources were not lacking. In addition, the succession to Emperor Maximilian, now blind and very ill, was approaching. The office of emperor, however, was not hereditary but elective, and Carlos I of Spain succeeded in earning the esteem of the German Prince-electors with the gold of Spain and was unanimously elected Holy Roman Emperor. Moreover, he was of the same opinion as his grandfather Ferdinand of Aragon (and Machiavelli) that 'nothing makes a prince so well esteemed as undertaking great enterprises and setting a fine example'.

He then restored the *Casa de la Contratación* for the implementation of the plan to reach the Moluccas by crossing the strait that would take the name of Magellan. It was the third time that this attempt was repeated, and this time it ended successfully, albeit at a very high price.

Knowledge Hegemonies 1 **212** Amerigo Vespucci: The Historical Context of His Explorations and Scientific Contribution, 211-214

Five brigantines, two of about 130 tons, two 90-ton whalers and a 60 ton caravel, loaded with enough food (biscuits, smoked meat and more) for two years for a crew of 234 men, took part in the enterprise. Two stops were planned in the New World: the first in the great gulf of Rio de la Plata and the second in the Gulf of San Julian at 49°S, where the fleet piloted by Vespucci had stopped in 1501.

It was a programme based on the one that failed ten years earlier, but with the explicit goal that the latitude of the Moluccan islands would be checked to determine whether, according to the Treaty of Tordesillas, they belonged to Spain or Portugal. The task of establishing the correct coordinates was entrusted to Ruy Faleiro, a Portuguese man who was also very angry with his country; he, however, fell ill before leaving and was replaced by Andrés de san Martin.

Another innovation was that the crew was not exclusively Spanish but international, including many Portuguese people and sailors from the Venetian and Genoese Republics.

During the ocean crossing, the first tensions began to emerge between Magellan and the Spanish captains. The ships reached the bay of Rio de Janeiro and lingered to explore the estuary of Rio della Plata, reaching the base of San Julian in December 1519, where the disagreements between the major captain and the other captains escalated. Some of these captains hatched a plot; Magellan became aware of it and reacted with extreme violence: the rebel leader was stabbed and his body was quartered; another was killed and two others, including the *veedor*, the supervisor of the expedition, were transported to a deserted place, and abandoned. In the end, the main captain had his way.

Another tragedy occurred when the ship *Santiago* was wrecked and the crew was saved with great difficulty. Due to all these troubles, the season suitable for crossing the strait was now over.

The sailors had to winter with reduced rations, the cold was intolerable, and many were eager to return to Spain. Finally the four ships entered/approached the strait; but the brigantine *San Antonio* disappeared. The searches for it were useless: it had deserted. Only three ships made their way into the Southern Ocean.

In November 1520, a year late, they crossed the strait later dedicated to Magellan, and faced the Ocean which was baptized with the name of Pacifico. The course through the ocean was completed in three months and 20 days, but the sailors paid a high price from hunger and scurvy: nineteen of them lost their lives.

When Magellan arrived at the islands – which would later be called the Philippines in honour of the infant Philip – he stopped in a city, Cebu, whose king welcomed him amicably. Magellan hastened to convert him and his people to Christianity and would have liked to convert the surrounding populations too, but found himself involved in a skirmish in which he was killed along with seven sailors.

The survivors elected a new captain and returned to those who had welcomed them, but this time a trap had been set and another 28 of them, including Captain Serrano who had succeeded Magellan, were slaughtered. The Basque pilot Sebastian Elcano took the lead, burned the ship that no longer had any crew, and with only two surviving ships, fled to the Moluccas. When he arrived he made no claim whatsoever, loaded the ship *Victoria* with spices and sailed with it towards the south-west, boldly pointing to the south of the Cape of Good Hope, to then sail northward without stopping up to the Cape Verde Islands.

There he took on fresh supplies and resumed the journey, escaping by a whisker from the Portuguese, but the 13 sailors who did not arrive in time to embark were reduced to slavery. Sebastian Elcano returned to Seville after exactly three years; eighteen survivors remained with him, including the chronicler of the expedition, Antonio Pigafetta of Vicenza, who had embarked at his own expense on behalf of the Venetian Republic. The other ship, the *Trinidad*, which had been left in a poor condition, was repaired by survivors of the crew who attempted to cross the Pacific eastwards, but it was intercepted by the Portuguese and the crew were also enslaved; only two sailors ever saw Europe again.

On November 7, 1523, Pigafetta reported this enterprise to the Council of Ten in Venice and the following year he obtained the privilege of printing his own narrative, which was published in 1524. It is a precious account of the very long and troubled navigation.1 Accidents, hunger and scurvy are reported, but there is also detailed technical information on all the places they reached. In the manner of Marco Polo, Pigafetta described how cities and islands were governed, which currencies were used and what their values were, the useful products to buy, the most requested goods, and what could be bartered. In addition to this, imitating Vespucci, he described in lively detail the appearance and behaviour of the populations he met, how those people ate, how they lit their fire, which weapons they used, how they adorned themselves, and their funerals and sexual habits. He also compiled long lists of words used in various indigenous languages, lists which later became precious to missionaries and linguists. In short, he was an observer free from prejudices and superstitions, who, however, sometimes exaggerated.

He described exotic plants and animals and even the beliefs of the populations he visited, always careful to specify what he saw with his own eyes and what he was told. He described the ʻclouds of Magellan' (the small satellite galaxy of our galaxy, already seen and described by Vespucci), but he was not good at astronomy nor in the art of navigation: the geographical coordinates he indicated are often erroneous.

The astronomer and cosmographer of the expedition had been killed in Cebu, and the indications by the other survivors of the long journey regarding the position of the Moluccas were very vague and were not sufficient to clarify the question that had given occasion to the enterprise: did the Spice Islands fall within the limits of the Treaty of Tordesillas? However, Carlos I, by now Holy Roman Emperor Charles V, had other major problems in those years, and renounced his claims (legitimate but not fair) on the Moluccas against a payment by the Portuguese of 350,000 gold ducats, while the Philippines remained with Spain. The sun never set on the empire of the twenty-one year old emperor.

1 Pigafetta's report was edited by Manfroni, *Relazione del primo viaggio intorno al mondo di Antonio Pigafetta*. Another excellent critical edition is the one edited by Andrea Canova (*Antonio Pigafetta, Relazione del primo viaggio attorno al mondo*). A complete documentation appears in: Compañía General de Tabacos de Filipinas, *Coleción general de documentos relativos a las Islas Filipinas etc*. A modern reconstruction, also based on other reports that have come to us, is provided by Bergreen, *Over the Edge of the World. Magellan's Terrifiying Circumnavigation of the Globe*.

**Amerigo Vespucci: The Historical Context of His Explorations and Scientific Contribution** Pietro Omodeo

### Bibliography

Airaldi, Gabriella; Varela, Consuelo. *Isabella di Castiglia: una ferrea vocazione al potere*. Genova: Costa & Nolan, 1992.

Alighieri, Dante. *Comedy: Introductory Readings of Selected Cantos*. Transl. by Uberto Limentani. Cambridge: Cambridge University Press, 1985.

Amado, Natalia Janaína; Figueiredo, Luiz Carlos. "A Certidão de Valentim Fernandes, documento pouco conhecido sobre o Brasil de 1500". *Textos de Historia*, 5, 1997, 133-442.

Arciniegas, Germàn. *Amerigo y el nuevo mundo*. Buenos Aires: Ed. Hermes, 1955.

Bezerra, José Augusto; Schwamborn, Ingrid. *A Carta de Américo Vespúcio, em Lisboa (1504) e o mapa de Martin Waldseemüller, com o nome America, delineando as terras do futuro Brasil (1507)*. Fortaleza: Edições Universidade Federal do Ceará, 2019. Bogdan, Henry. *La Lorraine des ducs*. Paris: Perrin, 2005.

Bonari, Bruno. *Amerigo Vespucci: La vita e i viaggi*. Firenze: Centro Editoriale Toscano, 2011.

Brotton, Jerry. *A History of the World in Twelve Maps*. London: Allen Lane, 2012.

Ferraro, Giuseppe. *Relazione delle scoperte fatte da C. Colombo, da A. Vespucci e da altri dal 1492 al 1506 tratta dai manoscritti della Biblioteca di Ferrara*. Bologna: Romagnoli, 1875.

Firpo, Luigi. *Colombo, Vespucci, Verrazzano*. Torino: UTET, 1966.

Folena, Gianfranco (a cura di). *Motti e facezie del Piovano Arlotto*. Milano; Modena: Ricciardi, 1953.

Formisano, Luciano. *Amerigo Vespucci, Lettere di viaggio*. Milano: Mondadori, 1985.

Galilei, Galileo. *Sidereus Nuncius*. Venezia: Baglioni, 1610.

Guidi Bruscoli, Francesco. *Bartolomeo Marchionni*. Firenze: Leo S. Olschki Editore, 2014. Harrisse, Henry. *The Discovery of North America*. Amsterdam: N. Israel, 1961.

Luzzana Caraci, Ilaria. *Amerigo Vespucci*. 2 vols. Roma: Istituto Poligrafico dello Stato, 1996-99. Nuova Raccolta Colombiana XXI.

Montaigne, Michel de. *Essais*. Bordeaux: Simon Millanges, 1580.

More, Thomas. *Libellus vere aureus, nec minus salutaris quam festivus, de optimo rei publicae statu deque nova insula Utopia*. Leuven: Dirk Martens, 1516.

Pallanti, Giuseppe. *La vera identità della Gioconda*. Milano: Skira, 2006.

Tooley, Ronald Vere. *The Mapping of America*. London: Holland Press, 1980.

Tripodi, Claudia. *Prima di Amerigo*. Roma: Viella, 2018.

	-

**Amerigo Vespucci: The Historical Context of His Explorations and Scientific Contribution** Pietro Omodeo

### Sources

Sources for the life and enterprises of Vespucci are his *Lettere* and the contemporary works that speak of him, as well as the many maps from the beginning of the sixteenth century based in some way on what he saw or learned from conversations with the Indios. His two works, one containing his astronomical observations, the other derived from the logbooks and notes concerning hiring and accounting, have been lost. The astronomical work could perhaps be partly reconstructed through the post-1501 writings of Abraham Zacuto, King Manuel's astronomer. *The Four Journeys*, several copies of which must have existed,could perhaps be found in some archive.

There are two editions of great philological value of the *Lettere familiari* and the *Lettere di viaggio*: the works of Luciano Formisano, *Amerigo Vespucci, Lettere di viaggio* and *Iddio ci dia buon viaggio e guadagno*. The latter work contains the entire critical edition of the *Codice Vaglienti* of the Biblioteca Riccardiana, ms. 1910. This codex, in addition to including most of Vespucci's *Lettere*, contains material of great interest for reconstruction of the environments in which his voyages of discovery took place.

Nothing emerges from these very careful editions that would make one suspect falsifications of Vespucci's writings by a foreign hand, while the gaps and some 'adjustments' dictated by the necessities of the moment for which Vespucci was responsible appear evident and can at times be integrated or corrected. See also Diego Álvarez Chanca: "Relación al Cabildo de Sevilla, 1494" (in Gil, Varela, *Cartas de particulares a Colón y relaciones coetáneas*).

Essential for an understanding of Ojeda's behaviour and his relations with Vespucci are: "Pesquisa contra Alonso de Ojeda sobre su premier viage á las Indias (1499)" (in Duquesa de Berwick y de Alba, *Autógrafos de Cristóbal Colón y Papeles de América*), and Vespucci's *Will* published by Varela in the appendix to her book *Colón y los florentinos*. Also in this work is Columbus's letter to his son Diego in which the Genoese navigator speaks of Amerigo Vespucci.

The cartography necessary to understanding Vespucci's itineraries is the following:

• Juan de La Cosa: map created for Queen Isabella (1500); Cantino Planisphere of 1502; *Planisphere* of Niccolò Caveri of 1502; Kunstermann Nautical map II of 1502; Waldseemüller Map of 1507; *Carta Marina* of 1516; south polar projection map by Pedro Reinel of c. 1522 (conserved in Istanbul); map of the World by Juan Vespucio of 1523.1

Knowledge Hegemonies 1 **222** Amerigo Vespucci: The Historical Context of His Explorations and Scientific Contribution, 221-222

1 A relevant publication has just appeared: Van Duzer, Martin Chet. *Waldseemüller's Carta marina of 1516: Study and Transcription of the Long Legends* (New York: Springer, 2020), which unfortunately could not be taken into account in this book.

**Biobibliographies**

**223**

A portrait of Pietro Omodeo by Huang Yongyu

**Pietro Omodeo** (Cefalù, 1919) attended the Sannazaro Classical High School in Naples and then studied Natural Sciences at the University of Pisa. He graduated under Giuseppe Colosi in 1940. He was a research assistant to Umberto Pierantoni and Emanuele Padoa, who were both scholars of vast scientific and humanist culture. He taught Biology, Zoology and Zoogeography at several universities. Moreover, he investigated the History of Scientific Thought and the History of Biology. Presently, he is an emeritus scholar at the University of Siena. Pietro Omodeo has edited the Italian editions of several works by Lamarck, Darwin and Diderot. He is the author of *Biologia* (1983); *Creazionismo ed evoluzionismo* (1984); *Biologia con rabbia e con amore* and *Gli abissi del tempo* (1989 and 2000); *Alle origini delle Scienze Naturali (1491-1632)* (2001). He has published many articles and monographs on Zoology, Theoretical Biology, the History of Science and Evolutionary Theory.

He is a member of the Accademia dei Fisiocritici of Siena (Siena Academy of Sciences) and is a recipient of the "Diploma di Medaglia d'Oro di Benemerito della Scuola, della Cultura e dell'Arte" from the Italian President Pertini. He retired in 1995 and, not knowing how to do anything else, continues to study.

**Pietro Daniel Omodeo** (New York, 1979), the editor of this book, is the grandson of Pietro Omodeo. He is a historian of science and professor of Historical epistemology at Ca' Foscari University of Venice, Italy. He is the Principal Investigator of the consolidator grant project *EarlyModernCosmology*, funded by the European Research Council (Horizon 2020, GA 725883), and the FARE project *EarlyGeoPraxis*, funded by the Italian Ministry of University and Research.

Printed on behalf of Edizioni Ca' Foscari - Digital Publishing, Venice in July 2020 by Logo s.r.l., Borgoricco, Padova Printed in Italy

This book offers a new reconstruction of Amerigo Vespucci's navigational and scientific endeavours in their historical context. The author argues that all of the manuscripts or texts that Vespucci left to posterity are reliable and true, except for several amendments imposed upon him for reasons linked to the political and economic interests of those who authorised him to undertake his journeys or which were the result of relationships with his companions. The earliest genuine documentation, which dates from the late fifteenth century or early sixteenth century, confirms this position. Fortunately, careful philological studies of Vespucci's principal written works are available, while some of his original drawings, which confirm, clarify and enrich what he narrated in his letters, can be identified in Waldseemüller's large map known as *Universalis cosmographia* (1507).

OMODEO

Università Ca'Foscari Venezia


**An Insightful Model to Study Innate Immunity and Stress Response in Deep‐Sea Vent Animals: Profiling the Mussel** *Bathymodiolus azoricus*

Raul Bettencourt, Inês Barros, Eva Martins, Inês Martins, Teresa Cerqueira, Ana Colaço, Valentina Costa, Domitília Rosa, Hugo Froufe, Conceição Egas, Sergio Stefanni, Paul Dando and Ricardo S. Santos

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/68034

#### **Abstract**

Deep‐sea environments are, in some cases, largely unexplored ecosystems, where life thrives driven by the geochemical features of each location. Among these environments, chemosynthesis‐based ecosystems, in the Mid Atlantic Ridge, have an exclusive combi‐ nation of high depth, high sulfur, and high methane concentrations. This is believed to modulate the biological composition of vent communities and influence the overall vent animal transcriptional activity of genes involved in adaptation processes to extreme envi‐ ronments. This opens, thus, the possibility of finding gene expression signatures specific to a given hydrothermal vent field. Regardless of the extreme physicochemical conditions that characterize deep‐sea hydrothermal vents, the animals dwelling around the vent sites exhibit high productivity and thus must cope with toxic nature of vent surrounding, seemingly deleterious to the animals, while developing surprisingly successful strategies to withstand adverse environmental conditions, including environmental microbes and mechanical stress whether ensuing from animal predation or venting activity. The deep‐ sea vent mussel *Bathymodiolus azoricus* has adapted well to deep‐sea extreme environ‐ ments and represents the dominating faunal community from hydrothermal vent sites in the Mid‐Atlantic Ridge, owing its successful adaptation and high biomasses to special‐ ized exploitation of methane and sulfide sources from venting activity. Its extraordinary capabilities of adapting and thriving in chemosynthesis‐based environments, largely devoid of photosynthetic primary production and characterized by rapid geochemical regime changes are due to symbiotic associations with chemosynthetic bacteria within its large gills. In an attempt to understand physiological reactions in animals normally set to endure extreme deep‐sea environments, our laboratory has undertaken, for the

© 2017 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

last few years, a series of investigations, aimed at characterizing molecular indicators of adaptation processes of which components of the host defense system has received most attention. This study reviews recent advances on the characterization of molecules and genes participating in immune reactions, using *in vivo* and *ex vivo* models, to elucidate cellular and humoral defense mechanisms in vent mussels and the strategies they have adopted to survive under extreme environments.

**Keywords:** innate immunity, deep‐sea hydrothermal vents, chemosynthetic ecosystems, long‐term acclimatization, host‐symbionts interactions, endosymbionts, differential gene expression, transcriptomics, mollusc bivalve, hydrothermal vent mussel, *Bathymodiolus azoricus*

### **1. Introduction**

Deep‐sea hydrothermal vents were discovered 40 years ago in the Galapagos Rift [1] reveal‐ ing for the first time, to the amazement of the scientific community, unusual life forms that have developed unique biochemical adaptations to high temperatures and toxic chemical nature of vent surrounding, otherwise harmful to life as we know it on the surface of the planet [2–5]. The animals dwelling around the vent sites exhibit high productivity and thus must cope with the seemingly deleterious physical and chemical conditions, while develop‐ ing surprisingly successful strategies to withstand adverse environmental conditions, includ‐ ing environmental microbes and mechanical stress whether due to animal predation or from deep‐sea volcanic eruptions [6–8].

At such depths and in the absence of light, life is thriving in chemosynthesis‐based ecosys‐ tems where most abundant marine invertebrates have developed mutualistic relationships with chemosynthetic bacteria. These symbiotic interactions are believed to play a crucial role in the survival of hydrothermal vent animals, driving their transcriptional activities, and their successful adaptation strategies to subsist under extreme environmental conditions. They essentially rely on the establishment of endosymbiosis relationships between vent animals and sulfur‐oxidizing (SOX) or methane‐oxidizing (MOX) bacteria [9–13].

Deep‐sea vent mussels of the *Bathymodiolus* genus are dominant members at hydrothermal vents and cold seep habitats. These mussels have the peculiarity of sheltering both endosymbi‐ otic sulfide‐oxidizing and methane‐oxidizing bacteria in their gills [9–13], supporting thus their endurance within this type of environment. *Bathymodiolus azoricus* is also the dominant species in deep‐sea hydrothermal vents in the Azores region and is well adapted to extreme conditions particularly to toxic concentrations of heavy metals, acidic pH, and absence of light [14–17].

In an attempt to understand physiological reactions of animals normally set to endure extreme conditions, in deep‐sea environments, our laboratory has undertaken, for the last 6 years, a series of investigations aimed at characterizing molecular indicators of adaptation processes of which components of the immune and stress‐related systems have received most of our attention [18, 19]. Central to our studies is the long‐term maintenance of vent mussels to atmospheric pressure proven to be a useful model to study unique molecular relationships under which the regulation of gene transcription may be affected by aquaria conditions and by the gradual disappearance of endosymbiont bacteria from gill epithelia [20]. Nonetheless, vent mussels subsist for months at atmospheric pressure in aquaria supplemented with plain sea water in or with artificial diet. This has allowed us to focus on developing experiments to investigate new physiological responses of animals sustaining experimental challenges involving immunological and stress‐related reactions and to provide new approaches to assess the effect of natural microorganisms and metal toxicity at vent environments [21, 22]. As a research model, the choice of the vent mussel *B. azoricus* is of great significance given its unique symbiosis with SOX and MOX bacteria. It has provided us with the means to under‐ standing the molecular mechanisms underlying immune reactions in animals normally set to endure extreme deep‐sea environments and the role of their symbiotic bacteria in controlling immune gene transcriptional activity.

In line with this, we have investigated main constituents of the vent mussel immune system and demonstrated how immune and stress genes could be modulated upon different experi‐ mental challenges in the absence of the characteristic high hydrostatic pressure found at deep‐ sea vent sites without methane and/or sulfide supplementation [21–23]. The proximity to the nearby hydrothermal vent fields, in the Azores region, has given us a geographical advan‐ tage for earning first insight into immediate physiological responses comprising both cellular and humoral responses of live mussels, freshly collected from the hydrothermal vents, which upon arrival, are acclimatized to our aquarium system, LabHorta [23–25]. The maintenance of live mussels in our laboratory is thus a key factor in gaining knowledge into the physiology of vent animals including the study of evolutionary conserved immune, inflammatory, and stress‐related factors commonly found in other marine bivalves [19, 26].