FAMILY Details for Potamotrygonidae

Family Potamotrygonidae - River stingrays
Order	:	Myliobatiformes
Class	:	Elasmobranchii
No. in FishBase	:	Genera : 5 \| Species : 40 Eschmeyer's Catalog of Fishes
Environment	:	Fresh : Yes \| Brackish : No \| Marine : Yes
Division	:	Peripheral/diadromous
Aquarium	:	none
First Fossil Record	:
Remark	:	Neotropical freshwater stingrays of the family Potamotrygonidae presently comprise three genera (Potamotrygon, Paratrygon and Plesiotrygon) and at least 18 species. The family has an extensive taxonomic history dating back to 1834, but was known long before formal taxonomic recognition (Castex, 1963a). Potamotrygonids are much maligned and feared because of their venomous caudal stings, but pose little or no threat if not stepped on or directly interfered with. The Potamotrygonidae is the only living chondrichthyan family restricted to freshwater habitats. Potamotrygonid stingrays are clearly monophyletic, sharing unique morphological and physiological specializations, including a pelvis with a greatly expanded anterior median process (pre-pelvic process), blood with low concentrations of urea, and reduction of the rectal gland (Garman, 1877; Thorson et al., 1983a). They are generally medium to large sized batoids, ranging from about 25 cm in disc width or length to more than 100 cm in adults of some species. Species of Potamotrygon have moderately stout and short tails, usually shorter than disc length, whereas Paratrygon and Plesiotrygon have slender, filiform and whiplike tails (in Paratrygon the tail is very long in juveniles but absolutely reduced in adults, and in Plesiotrygon it is much longer than disc length but also stout at base). The dorsal surface of the disc and tail are usually covered with many denticles, thorns and tubercles. The caudal sting (or serrated spine) is a rigid dermal derivative, located on the dorsal surface of the tail, containing small lateral serrations directed toward its base and an acute distal tip. The sting is reduced and situated closer to the tail base in Paratrygon, but well developed and located farther posteriorly in both Plesiotrygon and Potamotrygon. The stings contain longitudinal grooves to conduct venom produced in special glands at their bases, and are continuously worn, shed and replaced; up to four stings may be present in one individual. Additionally, many species have enlarged, non-venomous spines on disc margins or over tail, sometimes in numerous rows. The disc is usually slightly longer than wide (especially in Paratrygon), and covers most of the pelvic fins posteriorly (but less in Plesiotrygon). Dorsal and caudal fins are absent, but membranous skin folds (finfolds), with rudimentary internal radial elements, occur in Potamotrygon on both upper and lower tail midlines posterior to caudal stings (only ventral finfold is present in Plesiotrygon, and finfolds are absent in Paratrygon). The eyes are moderately large in Potamotrygon, but smaller and less protruded in Paratrygon and Plesiotrygon. Oral teeth are small with short cusps (more prominent in adult males), in usually less than 50 rows in either jaw (large specimens of Plesiotrygon may have more than 60 rows), and set in quincunx. Most potamotrygonid species have colorful dorsal arrangements, including spots of various dimensions, ocelli, reticulate patterns, and vermiform markings, which are generally species-specific, and grey, brown or black background coloration. Potamotrygonids are ovoviviparous (aplacentally viviparous), and the developing embryos are nourished by uterine milk secreted by trophonemata (Thorson et al., 1983b). Both uteri are functional and appear to be synchronous. Gestation may be restricted to certain stations or occur throughout the year, and the number of young produced in each gestation varies among species, but is usually from two to seven. Potamotrygonids only occur in South American rivers that drain into the Atlantic Ocean or Caribbean Sea. They are are conspicuously absent, however, from the São Francisco basin in northeastern Brazil, rivers that drain into the Atlantic from the Atlantic rainforest of northeastern and southeastern Brazil, the upper Paraná basin, and rivers south of the La Plata river in Argentina. Generally, most potamotrygonid species have distributions restricted to a single basin or river system, with only a few species present in more than one basin (e.g. Potamotrygon motoro, Potamotrygon orbignyi). Some species are even restricted to a single river (e.g. Potamotrygon leopoldi). This high endemism has led recent workers to express concern that some species may be endangered (Compagno & Cook, 1995; Rosa & Menezes, 1996), or are at least clearly vulnerable at present (two species are cited on the IUCN Red List as "data deficient"). Potamotrygonids are generally not consumed as food, but are commercialized in increasing quantity by the aquarium trade, and are only seldomly bred in captivity for commercial purposes. Further studies on their population structure and dynamics are therefore very much needed. The literature concerning potamotrygonids is vast. After the revision of Garman (1913), the next taxonomic study to treat the entire family is that of Rosa (1985a). Anatomical descriptions can be found in Garman (1877, 1913), Thorson & Watson (1975), Rosa (1985a), Nishida (1990), Taniuchi & Ishihara (1990), and Lovejoy (1996). Their phylogenetic relationships have been treated by Rosa (1985a), Dingerkus (1995), Lovejoy (1996) and McEachran et al. (1996). Accounts of their natural history are presented by Castex (1964a) and Castello (1975). Physiological aspects of potamotrygonids are summarized in Thorson et al. (1983a), and the reproductive biology of certain species by Thorson et al. (1983b), Teshima & Takeshita (1992), and Lasso et al. (1997a). Their historical biogeography has been studied by Brooks et al. (1981), Lovejoy (1996, 1997), Lovejoy et al. (1998), and Lundberg (1998). Recent descriptions of fossil remains (mostly isolated denticles) can be found in Deynat & Brito (1996) and Lundberg (1997). Recent taxonomic and historic compilations are those by Compagno & Cook (1995) and Zorzi (1995), and the extensive literature on potamotrygonid parasites is summarized in Brooks & Amato (1992). The following account is mostly based on original work by the first author, supplemented by information from Rosa (1985a) concerning type specimens of Potamotrygon deposited in museums in Argentina. This account differs from the revision of Rosa (1985a) in relation to the fate of various nominal species, and is also more conservative, recognizing fewer species. At least five new species have been found and are not included here (these are presently being described elsewhere). Taxonomic work on the family is constrained by the fact that many species of Potamotrygon are poorly described, lack adequate material, or present much intraspecific variation in coloration. This is compounded by generally overlapping meristic and morphometric features among species of Potamotrygon (both other genera are monotypic). Therefore, the approach adopted here has been to not recognize certain species that are inadequately defined at present, or that lack adequate material for proper characterization (e.g. Potamotrygon dumerilii,Potamotrygon humerosa). The current account is a working summary of the family, one that is subject to modifications as more collecting and research is conducted. This family is treated as it has traditionally been used in the literature, i.e. restricting it to Potamotrygon, Paratrygon and Plesiotrygon only, and refrain from including other genera that have recently been hypothesized as being their sister-taxa (amphi-American Himantura and Taeniura; Lovejoy, 1996; McEachran et al. 1996). Note that DW is disc width, and DL is disc length, which are standard measurements in stingrays (total length is usually not used as the distal tip of the tail is frequently missing in specimens).
Etymology	:	Greek, potamos = river + Greek, trigon = with three angles ( Ref. 45335).
Reproductive guild	:	bearers
Typical activity level	:
Main Ref.	:	de Carvalho, M.R., N. Lovejoy and R.S. Rosa 2003
Coordinator	:	de Carvalho, M.R., N. Lovejoy and R.S. Rosa 2003
Deep Fin Classification	:

Show species images | Show valid names | Nominal species list | CAS specimen photos | References

Species/Synonymy list for the family Potamotrygonidae as currently in FishBase

Important recommendation:

The list below must not be used as an authority reference synonymy list like those found in scientific published revisions, which must be the source to be used and cited eventually when they exist.

Rather, it reflects the current content of FishBase, and the progress with respect to synchronization with the Catalog of Fishes. However, we think it can be useful for users to assess the quality of information in FishBase, to start new work on the family, or to cross-check with other lists.

But we appreciate to be cited in publications when this list has been of any working value. In particular, for published scientific, we suggest then to cite it in the Material and Method section as a useful tool to conduct the research, but again, not as a taxonomic or nomenclatural authority reference.

Unless it is explicitly precised, the list is not complete, please search all original names published for the family in the Catalog of Fishes (genera, species), including those with uncertain or unknown status, that are not included in FishBase when they are not attached to a valid species.

This list uses some data from Catalog of Fishes (not shown but used to sort names).

The list ordered as follows:

When subfamilies are recognized, nominotypical subfamily first then other subfamilies by alphabetical order.
Type genus of the family first (or of subfamily when subfamilies are recognized) then other genera by chronological order of description (and alphabetical order).
Type species of the genus first by chronological order (and alphabetical order), with last listed misapplied names in a light gray font.
! Marks misspellings of the species names that must not be used.

Please send comments and corrections if you detect errors or missing names.

Show all | Show only accepted name | Show only accepted and original names

Scientifc name	Status	Senior/Junior synonym	Combination
Potamotrygoninae
Potamotrygon histrix (Müller & Henle, 1839)	accepted	senior	new
Trygon hystrix Müller & Henle, 1839	synonym	senior	original
! Potamotrygon hystrix (Müller & Henle, 1839)	synonym	senior	new
Trygon hystrix Müller & Henle, 1841	synonym	junior	original
Potamotrygon motoro (Müller & Henle, 1841)	accepted	senior	new
Taeniura motoro Müller & Henle, 1841	synonym	senior	original
Trygon garrapa Jardine, 1843	synonym	junior	original
Trygon mulleri Castelnau, 1855	synonym	junior	original
Potamotrygon circularis Garman, 1913	ambiguous	other	original
Potamotrygon laticeps Garman, 1913	synonym	junior	original
Paratrygon laticeps (Garman, 1913)	synonym	junior	new
Potamotrygon pauckei Castex, 1963	synonym	junior	original
Potamotrygon alba Castex, 1963	synonym	junior	original
Potamotrygon labradori Castex, 1963	synonym	junior	original
Potamotrygon henlei (Castelnau, 1855)	accepted	senior	new
Trygon henlei Castelnau, 1855	synonym	senior	original
Potamotrygon orbignyi (Castelnau, 1855)	accepted	senior	new
Trygon orbignyi Castelnau, 1855	synonym	senior	original
! Trygon dorbignyi Castelnau, 1855	synonym	senior	original
! Trygon d'orbignyi Castelnau, 1855	synonym	senior	original
Trygon dumerilii Castelnau, 1855	synonym	junior	original
Potamotrygon dumerilii (Castelnau, 1855)	synonym	junior	new
Trygon reticulatus Günther, 1880	synonym	junior	original
Potamotrygon reticulatus (Günther, 1880)	synonym	junior	new
Potamotrygon roulini Roberts, 2021	synonym	junior	original
Potamotrygon humerosus (non Garman, 1913)	misapplied	misapplied	original
Potamotrygon magdalenae (Duméril, 1865)	accepted	senior	new
Taeniura magdalenae Duméril, 1865	synonym	senior	original
Trygon hystrix (non Müller & Henle, 1841)	misapplied	misapplied	original
Potamotrygon brachyura (Günther, 1880)	accepted	senior	new
Trygon brachyurus Günther, 1880	synonym	senior	original
Potamotrygon brumi Devincenzi, 1942	synonym	junior	original
Potamotrygon constellata (Vaillant, 1880)	accepted	senior	new
Taeniura constellata Vaillant, 1880	synonym	senior	original
! Toeniura constellata Vaillant, 1880	synonym	senior	original
Potamotrygon circularis Garman, 1913	ambiguous	other	original
Potamotrygon ocellata (Engelhardt, 1912)	accepted	senior	new
Trygon hystrix ocellata Engelhardt, 1912	synonym	senior	original
Potamotrygon humerosa Garman, 1913	accepted	senior	original
! Potamotrygon humerosus Garman, 1913	synonym	senior	original
Potamotrygon scobina Garman, 1913	accepted	senior	original
Potamotrygon signata Garman, 1913	accepted	senior	original
! Potamotrygon signatus Garman, 1913	synonym	senior	original
Potamotrygon schroederi Fernández-Yépez, 1958	accepted	senior	original
Potamotrygon falkneri Castex & Maciel, 1963	accepted	senior	original
Potamotrygon menchacai Martínez Achenbach, 1967	synonym	junior	original
Potamotrygon castexi Castello & Yagolkowski, 1969	synonym	junior	original
Potamotrygon schuhmacheri Castex, 1964	accepted	senior	original
! Potamotrygon schuehmacheri Castex, 1964	synonym	senior	original
! Potamotrygon schuemacheri Castex, 1964	synonym	senior	original
Potamotrygon leopoldi Castex & Castello, 1970	accepted	senior	original
Potamotrygon yepezi Castex & Castello, 1970	accepted	senior	original
Potamotrygon marinae Deynat, 2006	accepted	senior	original
Potamotrygon boesemani Rosa, Carvalho & Almeida Wanderley, 2008	accepted	senior	original
Potamotrygon tatianae Silva & Carvalho, 2011	accepted	senior	original
Potamotrygon tigrina Carvalho, Sabaj Pérez & Lovejoy, 2011	accepted	senior	original
Potamotrygon amandae Loboda & Carvalho, 2013	accepted	senior	original
Potamotrygon pantanensis Loboda & Carvalho, 2013	accepted	senior	original
Potamotrygon limai Fontenelle, Da Silva & Carvalho, 2014	accepted	senior	original
Potamotrygon albimaculata Carvalho, 2016	accepted	senior	original
Potamotrygon jabuti Carvalho, 2016	accepted	senior	original
Potamotrygon rex Carvalho, 2016	accepted	senior	original
Potamotrygon wallacei Carvalho, Rosa & Araújo, 2016	accepted	senior	original
Potamotrygon adamastor Fontenelle & Carvalho, 2017	accepted	senior	original
Potamotrygon amazona Fontenelle & Carvalho, 2017	accepted	senior	original
Potamotrygon garmani Fontenelle & Carvalho, 2017	accepted	senior	original
Potamotrygon marquesi Silva & Loboda, 2019	accepted	senior	original
Paratrygon aiereba (Müller & Henle, 1841)	accepted	senior	new
Trygon aiereba Müller & Henle, 1841	synonym	senior	original
Raja ajereba Walbaum, 1792	synonym	junior	original
Paratrygon ajereba (Walbaum, 1792)	synonym	junior	new
! Paratrygon aiereba (Walbaum, 1792)	synonym	junior	new
Trygon strogylopterus Jardine, 1843	synonym	junior	original
Disceus thayeri Garman, 1913	synonym	junior	original
Elipesurus spinicauda (non Schomburgk, 1843)	misapplied	misapplied	original
Paratrygon orinocensis Loboda, Lasso, Rosa & Carvalho, 2021	accepted	senior	original
Paratrygon parvaspina Loboda, Lasso, Rosa & Carvalho, 2021	accepted	senior	original
Plesiotrygon iwamae Rosa, Castello & Thorson, 1987	accepted	senior	original
Elipesurus strogylopterus (non Schomburgk, 1843)	misapplied	misapplied	misapplied
Potamotrygon scobina (non Garman, 1913)	misapplied	misapplied	original
Plesiotrygon nana Carvalho & Ragno, 2011	accepted	senior	original
Heliotrygon gomesi Carvalho & Lovejoy, 2011	accepted	senior	original
Heliotrygon rosai Carvalho & Lovejoy, 2011	accepted	senior	original
Styracurinae
Styracura schmardae (Werner, 1904)	accepted	senior	new
Trygon schmardae Werner, 1904	synonym	senior	original
Dasyatis schmardae (Werner, 1904)	synonym	senior	new
Himantura schmardae (Werner, 1904)	synonym	senior	new
! Himantura schmarde (Werner, 1904)	synonym	senior	new
Styracura pacifica (Beebe & Tee-Van, 1941)	accepted	senior	new
Dasyatis pacificus Beebe & Tee-Van, 1941	synonym	senior	original
Himantura pacifica (Beebe & Tee-Van, 1941)	synonym	senior	new