Françoise and Claude Monniot perform with great talent the profession of systematist. Researchers at the National Museum of Natural History, they spend over thirty years of their lives to classify, study species coming from the whole world. They became the world specialists of a marine invertebrates group called ascidians, unknown animals. Divers themselves, they are called to participate in national and international scientific expeditions, where the association of taxonomists and other specialists such as chemists, geneticists, etc. ... is essential. Unfortunately this speciality is disappearing and current budgets do not allow training students.