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Pascal Deynat | |
|---|---|
 Pascal Deynat studying the skin coating of a sixgill shark | |
| Born | January 15, 1965 |
| Nationality | French |
| Title | Ichthyologist |
Pascal Deynat is a French naturalist and a professor in Paris Diderot University. An Ichthyologist by training, he is a specialist in the study of skin coating of cartilaginous fishes as part of the Odontobase Project. [1]
In 1994, he wrote his first article on the loops of Potamotrygonidae's fossil along with his friend, a Brazilian paleontologist Paulo Brito. [2] His first work on the relationship between the cutaneous denticles of sharks and their ecology was presented at the 7th International Congress of Ichthyology at The Hague. [3]
In 1994, Deynat continued his doctoral research on the systematic and taxonomic applications of the skin covering of Pristiformes and Rajiformes, which he completed with a 15-day stay at the American Museum of Natural History in New York City and at the Smithsonian Institution in Washington. [4]
In 1997, he participated in the production of a poster for Overseas Scientific and Technical Research Office. [5] In the same year, Professor Guy Duhamel offered him a job as a fisheries controller in the Kerguelen Islands without sufficient preparations. Deynat's aquaphobia caused the mission to fail, and he was then forced to leave his host laboratory to find work as a salesman with the bookstore Gibert Joseph.
In 2000, while handling the CD-ROMs of a paleontology database named Paleobase, Deynat had the idea of creating Odontobase to identify and catalog the odontodes (cutaneous denticles, spines and loops) of all species of chondrichthyans. He was working on the project while presenting the subject of his original research to the media. [6] The detailed study of the variations of the cutaneous coating allowed him to discover a new type of denticles, the myrmecoid denticles, typical of tha Raja of the eastern Atlantic. [7] In parallel with his activities, the Gibert Joseph bookstore authorized him to present a photographic exhibition of electron microscopy called "Shark on edge", produced jointing with the National Museum of Natural History.
In 2005, based solely on the characteristics of the skin covering, Deynat demonstrated that saw-fish of the genus Pristis, can be divided into two groups according to the characteristics of their denticles, and the conclusion was identical to a genetic study carried out a few months later. [8] At the end of 2006, he was given the opportunity to use the characteristics of the skin covering for a practical purpose, that of identifying the isolated fins of sharks. This project was done in collaboration with the World Wide Fund for Nature, Shark Alliance and QUAE for fighting against shark finning. While continuing to work on it, his revision work on the skin covering of Potamotrygonidae enabled him to discover a new species from Guyana, which he named with the first name of his daughter Marina, Potamotrygon Marinae. [9] This discovery allowed him to re-emphasize his research with the mainstream press, and raise public awareness of pinning by participating in a debate organized in 2007 as part of the Jules Verne Aventures Festival. [10] He continued his work alone, and in 2009 he published a book for the general public on fish and marine mammals. [11]
In 2010, Deynat's work on the identification of fins was published, which earned him many congratulations without having much concrete effects on the fate of sharks. [12] By continuing the general study of cartilaginous fishes, the Odontobase was completed, which sheded light on the shark attacks that occurred in Réunion in 2011 and 2012. [13] In 2012, he won a legal case against the Encyclopædia Universalis, but lost a case against the marked posts of the National Museum of Natural History in Paris. He therefore continued his research on the applications of Odontobase in the identification of objects covered with stingray, but also in the identification of shark fins for customs services. His specialty allowed him to contribute to various exhibitions, including that of the Oceanographic Museum of Monaco, where he became a leading expert on skin coverings. In 2015, he participated in the short films of La Belle Société Production. [14]
Since 2016, Deynat has been working on writing articles that he had left pending, and continuing his collaborations with scientific organizations in the enrichment of Odontobase and the identification of objects covered with skins of sharks and rays. [15] As of 2020, a new database on the characteristics of the skin covering of bony fish was set up to help refine the identification of ethnological objects.
In 1991, Deynat obtained a scholarship from the Fondation Marcel Bleustein-Blanchet, whose sponsor was the Prince of Monaco, Rainier III. [16]
In 2016, he was proposed to join the jury for the "taste of science" prize, organized since 2009 by the Minister of Higher Education, Research and Innovation, alongside biologist Pierre-Henri Guyon and prehistorian Marylène Pathou-Mathis. [17] He met the Secretary of State for Research, Thierry Mandon. In 2017, he also met the Minister of Research Frédérique Vidal during the "science for all" operation at the Gibert Joseph bookstore.
In 2020, he was a member of the jury of the Parish Shark Fest, and participated there every year as a guest ever since. [18]
Deynat also became involved in scientific dissemination and the fight against the trafficking of endangered species. During his years in Amiens, he participated in the Culture and Sciences association, housed in the former house of Jules Verne, down the rue Charles Dubois where he himself lived. During these years, he co-directed a biology-geology workshop, developed an exhibition on sea creatures, and was the editor-in-chief of the association's journal. [19]
Deynat also participated in a number of radio programs, and wrote several articles in the press. [20] [21] [22] [23] [24] [25] [26] He also participated in some written interviews. [27] [28]
Chondrichthyes is a class that contains the cartilaginous fishes that have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or bony fishes, which have skeletons primarily composed of bone tissue. Chondrichthyes are jawed vertebrates with paired fins, paired nares, scales, and a heart with its chambers in series. Extant chondrichthyes range in size from the 10 cm finless sleeper ray to the 10 m whale shark.
Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. Modern sharks are classified within the clade Selachimorpha and are the sister group to the Batoidea. Some sources extend the term "shark" as an informal category including extinct members of Chondrichthyes with a shark-like morphology, such as hybodonts. Shark-like chondrichthyans such as Cladoselache and Doliodus first appeared in the Devonian Period, though some fossilized chondrichthyan-like scales are as old as the Late Ordovician. The oldest modern sharks (selachians) are known from the Early Jurassic, about 200 Ma.
Myliobatiformes is one of the four orders of batoids, cartilaginous fishes related to sharks. They were formerly included in the order Rajiformes, but more recent phylogenetic studies have shown the myliobatiforms to be a monophyletic group, and its more derived members evolved their highly flattened shapes independently of the skates.
Skates are cartilaginous fish belonging to the family Rajidae in the superorder Batoidea of rays. More than 150 species have been described, in 17 genera. Softnose skates and pygmy skates were previously treated as subfamilies of Rajidae, but are now considered as distinct families. Alternatively, the name "skate" is used to refer to the entire order of Rajiformes.
Elasmobranchii is a subclass of Chondrichthyes or cartilaginous fish, including sharks, rays, skates, and sawfish. Members of this subclass are characterised by having five to seven pairs of gill clefts opening individually to the exterior, rigid dorsal fins and small placoid scales on the skin. The teeth are in several series; the upper jaw is not fused to the cranium, and the lower jaw is articulated with the upper. The details of this jaw anatomy vary between species, and help distinguish the different elasmobranch clades. The pelvic fins in males are modified to create claspers for the transfer of sperm. There is no swim bladder; instead, these fish maintain buoyancy with large livers rich in oil.
The guitarfish, also referred to as shovelnose rays, are a family, Rhinobatidae, of rays. The guitarfish are known for an elongated body with a flattened head and trunk and small, ray-like wings. The combined range of the various species is tropical, subtropical, and warm temperate waters worldwide.
Rajiformes is one of the four orders in the superorder Batoidea, flattened cartilaginous fishes related to sharks. Rajiforms are distinguished by the presence of greatly enlarged pectoral fins, which reach as far forward as the sides of the head, with a generally flattened body. The undulatory pectoral fin motion diagnostic to this taxon is known as rajiform locomotion. The eyes and spiracles are located on the upper surface of the head and the gill slits are on the underside of the body. Most species give birth to live young, although some lay eggs enclosed in a horny capsule.
The bramble shark is one of the two species of sharks in the family Echinorhinidae. Aside from the eastern Pacific Ocean, it is found in tropical and temperate waters worldwide. This rarely encountered shark swims close to the bottom of the seafloor, typically at depths of 400–900 m (1,300–3,000 ft), though it may enter much shallower water. The bramble shark has a stout body with two small dorsal fins positioned far back and no anal fin. It can be readily identified by the large, thorn-like dermal denticles scattered over its body, some of which may be fused together. It is purplish brown or black in color and grows up to 3.1 m (10 ft) long.
River stingrays or freshwater stingrays are Neotropical freshwater fishes of the family Potamotrygonidae in the order Myliobatiformes, one of the four orders of batoids, cartilaginous fishes related to sharks. They are found in rivers in tropical and subtropical South America. A single marine genus, Styracura, of the tropical West Atlantic and East Pacific are also part of Potamotrygonidae. They are generally brownish, greyish or black, often with a mottled, speckled or spotted pattern, have disc widths ranging from 31 to 200 centimetres (1.0–6.6 ft) and venomous tail stingers. River stingrays feed on a wide range of smaller animals and the females give birth to live young. There are more than 35 species in five genera.
The Urolophidae are a family of rays in the order Myliobatiformes, commonly known as stingarees or round stingrays. This family formerly included the genera Urobatis and Urotrygon of the Americas, which are presently recognized as forming their own family Urotrygonidae. Stingarees are found in the Indo-Pacific region, with the greatest diversity off Australia. They are sluggish, bottom-dwelling fish that have been recorded from shallow waters close to shore to deep waters over the upper continental slope. Measuring between 15 and 80 cm long, these rays have oval to diamond-shaped pectoral fin discs and relatively short tails that terminate in leaf-shaped caudal fins, and may also have small dorsal fins and lateral skin folds. Most are smooth-skinned, and some have ornate dorsal color patterns.
The sixgill stingray is a species of stingray and the only extant member of the family Hexatrygonidae. Although several species of sixgill stingrays have been described historically, they may represent variations in a single, widespread species. This flabby, heavy-bodied fish, described only in 1980, is unique among rays in having six pairs of gill slits rather than five. Growing up to 1.7 m (5.6 ft) long, it has a rounded pectoral fin disc and a long, triangular, and flexible snout filled with a gelatinous substance. It is brownish above and white below, and lacks dermal denticles.
The deepwater stingray or giant stingaree is a species of stingray and the sole member of the family Plesiobatidae. It is widely distributed in the Indo-Pacific, typically over fine sediments on the upper continental slope at depths of 275–680 m (900–2,230 ft). This species reaches 2.7 m (8.9 ft) in length and 1.5 m (4.9 ft) in width. It has an oval pectoral fin disc with a long, flexible, broad-angled snout. Most of the entire latter half of its tail supports a distinctively long, slender, leaf-shaped caudal fin. Its coloration is dark above and white below, and its skin is almost completely covered by tiny dermal denticles.
The cloudy catshark is a common species of catshark, belonging to the family Scyliorhinidae. It is a bottom-dweller that inhabits rocky reefs in the northwestern Pacific Ocean, from the shore to a depth of 320 m (1,050 ft). Growing up to 50 cm (20 in) long, this small, slim shark has a narrow head with a short blunt snout, no grooves between the nostrils and mouth, and furrows on the lower but not the upper jaw. It is also characterized by extremely rough skin and coloration consisting of a series of dark brown saddles along its back and tail, along with various darker and lighter spots in larger individuals.
The West African catshark is a catshark of the family Scyliorhinidae. It is found in the eastern Atlantic between latitudes 20° N and 17° S, at depths between 45 and 500 m. It can grow up to a length of 80 centimetres (31 in). At one time, the West African catshark was considered to be a subspecies of the nursehound, Scyliorhinus stellaris, but is now considered to be a separate species. The reproduction of this catshark is oviparous.
Philippe Victor Diolé was a French author and undersea explorer.
Son of the Shark is a 1993 French film directed by Agnes Merlet, about two brothers, Martin and Simon, and their adventures as juvenile delinquents in the north of France.
Platyrhina is a genus of rays in the family Platyrhinidae, containing three species. They are native to the warm-temperate to tropical marine waters in the western Pacific Ocean. They are little-known bottom-dwellers that feed on small invertebrates such as crustaceans, molluscs, and worms. The fanray is found inshore to a depth of 60 m on rocky or rock sandy bottoms.
Batoidea is a superorder of cartilaginous fishes, commonly known as rays. They and their close relatives, the sharks, comprise the subclass Elasmobranchii. Rays are the largest group of cartilaginous fishes, with well over 600 species in 26 families. Rays are distinguished by their flattened bodies, enlarged pectoral fins that are fused to the head, and gill slits that are placed on their ventral surfaces.
A fish scale is a small rigid plate that grows out of the skin of a fish. The skin of most jawed fishes is covered with these protective scales, which can also provide effective camouflage through the use of reflection and colouration, as well as possible hydrodynamic advantages. The term scale derives from the Old French escale, meaning a shell pod or husk.
Pascal-Alex Vincent is a French director, author of original work, screenwriter, and voice-over.
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