The sharpsnout stingray or wingfin stingray (''Fontitrygon geijskesi'') is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

stingray Stingrays are a group of sea Batoidea, rays, a type of cartilaginous fish. They are classified in the suborder Myliobatoidei of the order Myliobatiformes and consist of eight families: Hexatrygonidae (sixgill stingray), Plesiobatidae (deepwate ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Dasyatidae, found from off

Venezuela Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It com ...

to northern

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

. It inhabits shallow,

brackish water Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuary ...

, shifting towards the coast in the

dry season The dry season is a yearly period of low rainfall, especially in the tropics. The weather in the tropics is dominated by the tropical rain belt, which moves from the northern to the southern tropics and back over the course of the year. The t ...

and away from it in the

rainy season The rainy season is the time of year when most of a region's average annual rainfall occurs. Rainy Season may also refer to: * ''Rainy Season'' (short story), a 1989 short horror story by Stephen King * "Rainy Season", a 2018 song by Monni * '' ...

. Typically measuring across, this dark brown ray is easily identifiable by its long, projecting snout and elongated, acutely pointed

pelvic fin Pelvic fins or ventral fins are paired fins located on the ventral (belly) surface of fish, and are the lower of the only two sets of paired fins (the other being the laterally positioned pectoral fins). The pelvic fins are homologous to the hi ...

s. Its diet consists of

bottom-dwelling The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from the Ancient Greek word (), meaning "the depths". ...

invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...

s. Reproduction is

aplacental viviparous Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a "bridging" form of reproduction between egg-laying oviparous and live-bearing viviparous reproduction. Ovoviviparous animals possess embryos that develop inside eggs that rema ...

, with females bearing one to three pups annually. Naturally uncommon and slow-reproducing, the sharpnose stingray is under pressure by both

artisanal An artisan (from , ) is a skilled craft worker who makes or creates material objects partly or entirely by hand. These objects may be functional or strictly decorative, for example furniture, decorative art, sculpture, clothing, food ite ...

and

commercial fisheries Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must often p ...

, leading the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the stat ...

(IUCN) to assess it as critically endangered.

Taxonomy and phylogeny

Dutch Dutch or Nederlands commonly refers to: * Something of, from, or related to the Netherlands ** Dutch people as an ethnic group () ** Dutch nationality law, history and regulations of Dutch citizenship () ** Dutch language () * In specific terms, i ...

ichthyologist Ichthyology is the branch of zoology devoted to the study of fish, including bony fish (Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha). According to FishBase, 35,800 species of fish had been described as of March 2 ...

Marinus Boeseman described the sharpsnout stingray in a 1948 issue of the

scientific journal In academic publishing, a scientific journal is a periodical publication designed to further the progress of science by disseminating new research findings to the scientific community. These journals serve as a platform for researchers, schola ...

''Zoologische Mededelingen'', based on a juvenile male caught off

Suriname Suriname, officially the Republic of Suriname, is a country in northern South America, also considered as part of the Caribbean and the West Indies. It is a developing country with a Human Development Index, high level of human development; i ...

with a disc length of . The whereabouts of this

type specimen In biology, a type is a particular wikt:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally associated. In other words, a type is an example that serves to ancho ...

is unknown.Catalog of Fishes (Online Version)
California Academy of Sciences. Retrieved on November 24, 2009. In a 2001

phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

analysis based on morphological characters, Lisa Rosenberger found that the

longnose stingray The longnose stingray (''Hypanus guttatus'') is a species of stingray in the family Dasyatidae, native to the western Atlantic Ocean from the southern Gulf of Mexico to Brazil. Found in coastal waters no deeper than , this demersal species favor ...

(''Hypanus guttata'') is the

sister species In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

of the sharpsnout stingray, and that the two form a

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

with the pale-edged stingray (''Telatrygon zugei''), the

pearl stingray The pearl stingray (''Fontitrygon margaritella'') is a little-known species of stingray in the family Dasyatidae, found in shallow coastal waters from Mauritania to Angola, though fossils have been found in Portugal. Growing to across, this spe ...

(''Fontitrygon margaritella''), the sharpnose stingray (''Maculabatis gerrardi''), and the

smooth butterfly ray The smooth butterfly ray (''Gymnura micrura'') is a species of Chondrichthyes, cartilaginous fish in the family Gymnuridae. It is a member of the order Myliobatiformes, which contains 10 total families. Its natural habitats are shallow seas, subt ...

(''Gymnura micrura'', included in the study as an

outgroup Outgroup may refer to: * Outgroup (cladistics), an evolutionary-history concept * Outgroup (sociology) In social psychology and sociology, an in-group is a social group to which a person psychologically identifies as being a member. By cont ...

). These results support the growing consensus that neither ''

Dasyatis ''Dasyatis'' (Greek alphabet, Greek δασύς ''dasýs'' meaning wikt:rough, rough or Density, dense and βατίς ''batís'' meaning Skate (fish), skate) is a genus of stingray in the family (biology), family Dasyatidae that is native to the ...

'' nor ''

Himantura ''Himantura'' is a genus of stingray in the family (biology), family Dasyatidae that is native to the Indo-Pacific. In a 2016 Taxonomy (biology), taxonomic revision, many of the species formerly assigned to ''Himantura'' were reassigned to other ...

'' are

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

Distribution and habitat

One of the less common stingrays within its

range Range may refer to: Geography * Range (geographic), a chain of hills or mountains; a somewhat linear, complex mountainous or hilly area (cordillera, sierra) ** Mountain range, a group of mountains bordered by lowlands * Range, a term used to i ...

, the sharpsnout stingray is found in nearshore,

s along the northeastern coast of

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

, from

and

Trinidad and Tobago Trinidad and Tobago, officially the Republic of Trinidad and Tobago, is the southernmost island country in the Caribbean, comprising the main islands of Trinidad and Tobago, along with several List of islands of Trinidad and Tobago, smaller i ...

to northern

; many occur in the

estuarine An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environm ...

area affected by the

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include non-salty mi ...

discharge of the Amazon River. It favors muddy habitats deep, with low visibility. However, Uyeno ''et al.'' (1983) gave a depth of for this species. The sharpsnout stingray conducts annual movements that are affected by

salinity Salinity () is the saltiness or amount of salt (chemistry), salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensio ...

, entering coastal bays such as Marajó Bay during the

and shifting to offshore waters during the

Description

The

pectoral fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish aquatic locomotion, swim. Apart from the tail or caudal fin, fish fins have no direct connection with the vertebral column ...

disc of the sharpsnout stingray is about as wide as long, with strongly concave leading margins and rounded corners. The snout is long and projecting, measuring 39–54% as long as the disc is wide. The eyes are minute and followed by much larger spiracles. There is a flap of skin between the nares, with a finely fringed posterior margin. The line of the mouth is slightly indented at the center. The upper and lower jaws both contain 56–68 tooth rows; the teeth are blunt and arranged with a

quincunx A quincunx ( ) is a geometry, geometric pattern consisting of five points arranged in a cross, with four of them forming a Square (geometry), square or rectangle and a fifth at its center. The same pattern has other names, including "in saltire" ...

pattern. A transverse row of 5

papilla Papilla (Latin, 'nipple') or papillae may refer to: In animals * Papilla (fish anatomy), in the mouth of fish * Papilla (worms), small bumps on the surface of certain worms * Basilar papilla, a sensory organ of lizards, amphibians and fish * ...

e are present on the floor of the mouth. The

s are distinctive, being over twice as long as wide with a gently sinuous trailing margin, and tapering to an acute tip that sometimes extends past the disc. The whip-like tail measures over twice the length of the disc and bears 1–2 serrated spines on top. Posterior to the spines are a subtle dorsal keel and a ventral fin fold about half as long as the disc. A band of small tubercles runs along the dorsal midline from behind the eyes to the base of the tail (excluding a posterior portion of the disc), with larger tubercles in a central row and on each "shoulder". More conical tubercles are scattered over the upper surface of the tail past the spines. The coloration is a uniform brown above, and white below darkening towards the disc margin. This species typically attains a disc width of , but individuals up to across have been recorded.

Biology Biology is the scientific study of life and living organisms. It is a broad natural science that encompasses a wide range of fields and unifying principles that explain the structure, function, growth, History of life, origin, evolution, and ...
and
ecology Ecology () is the natural science of the relationships among living organisms and their Natural environment, environment. Ecology considers organisms at the individual, population, community (ecology), community, ecosystem, and biosphere lev ...

The sharpsnout stingray feeds on small burrowing

s such as

worm Worms are many different distantly related bilateria, bilateral animals that typically have a long cylindrical tube-like body, no limb (anatomy), limbs, and usually no eyes. Worms vary in size from microscopic to over in length for marine ...

crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

s, and

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

s, excavating them from the substrate and grinding them apart with its pavement-like teeth. Like other stingrays, this species is

, with females giving birth to 1–3 young every year. Similarly to the Colares stingray (''Fontitrygon colarensis''), the annual movements of this ray may relate to reproduction as most females found near the coast are newly impregnated. Younger individuals have proportionately longer tails (measuring up to three times the disc width) than adults.

Human interactions

The sharp,

venom Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a sti ...

ous tail spines of the sharpsnout stingray are potentially hazardous to humans. This species is caught by hook-and-line or in nets; it is used for food by subsistence fishers, but is not favored because its flesh is a dark reddish color. Sharpsnout stingrays also form part of the

bycatch Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juve ...

of artisanal and

targeting large

catfish Catfish (or catfishes; order (biology), order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Catfish are common name, named for their prominent barbel (anatomy), barbels, which resemble a cat's whiskers, though not ...

in the Amazon estuary, while increasing interest in using stingrays for minced fish products may intensify fishing pressure on this species in the future. Because of these threats and the slow reproductive rate of this ray, the

(IUCN) has assessed it as

Critically Endangered An IUCN Red List critically endangered (CR or sometimes CE) species is one that has been categorized by the International Union for Conservation of Nature as facing an extremely high risk of extinction in the wild. As of December 2023, of t ...

References

{{Taxonbar, from=Q143869 sharpsnout stingray Marine fish of Brazil Fish of Colombia Fish of Guyana Fish of Suriname Marine fish of Venezuela Fish of the Caribbean Fontitrygon Taxa named by Marinus Boeseman Taxonomy articles created by Polbot