Results 191 to 200 of about 519,530 (231)

Phylogeography, genetic diversity and population structure of the freshwater stingray, Paratrygon aiereba (Müller & Henle, 1841) (Myliobatiformes: Potamotrygonidae) in the Colombian Amazon and Orinoco basins

Mitochondrial DNA. Part A, DNA mapping, sequencing, and analysis, 2020
The freshwater stingray Paratrygon aiereba have coloration, osteological and morphometric variations that could suggest the existence of more than one species in Colombia.
Maira A. Rizo-Fuentes, Camilo A. Correa-Cárdenas, C. Lasso, Mónica A Morales-Betancourt, Dalia C. Barragán-Barrera, S. Caballero   +5 more
semanticscholar   +1 more source

Effects of biological traits on capture-induced parturition in a freshwater stingray and perspectives for species management.

Journal of Fish Biology, 2020
Elasmobranchs are particularly vulnerable to overexploitation and population depletion, especially due to their life-history traits, such as low reproductive output and slow growth.
Bianca Sousa Rangel, Douglas Castro Ribeiro, J. M. A. Chagas, L. Spada, R. G. Moreira, C. Ribeiro   +5 more
semanticscholar   +1 more source

Anatomy of the Ampullary Electroreceptor in the Freshwater Stingray, Himantura signifer

Copeia, 1997
An examination of the electroreceptive anatomy in the Southeast Asian freshwater stingray Himantura signifer shows it to consist of "miniampullae" which are intermediate in size between the longer ampullae of Lorenzini that typify marine taxa and the microampullae characteristic of neotropical, freshwater potamotrygonids.
William Raschi, Elaine D. Keithan, William C. H. Rhee   +2 more
openaire   +1 more source

Remodeling of Uterine Tissues During Gestation of Potamotrygon wallacei (Elasmobranchii), a Neotropical Freshwater Stingray Endemic to the Negro River, Central Amazonia

Journal of morphology
Neotropical freshwater stingrays of the subfamily Potamotrygoninae exhibit aplacental viviparity with uterine trophonemata. In this reproductive mode, females nourish and provide oxygenation to the embryo via the mucosa of the uterine wall.
Michelly Siqueira-Souza, M. G. Amazonas, K. Yamamoto, W. Duncan   +3 more
semanticscholar   +1 more source

Updating status of the distributional records of giant freshwater stingray Urogymnus polylepis (Bleeker, 1852) in Indonesia

, 2020
The Giant Freshwater Stingray Urogymnus polylepis (Bleeker, 1852) has been known from several drainages in Sunda land (Sumatra, Kalimantan and Java). We compiled most recent update records of U.
M. Iqbal, Arum Setiawan, Y. Windusari, I. Yustian, H. Zulkifli   +4 more
semanticscholar   +1 more source

Morphology and Morphometry of the Ovaries and Uteri of the Amazonian Freshwater Stingrays (Potamotrygonidae: Elasmobranchii)

The Anatomical Record, 2016
ABSTRACTThe reproductive biology of South American freshwater stingrays (family Potamotrygonidae) is still poorly studied compared to other marine species. In the present study, we examined the gross anatomy and histology of six species of potamotrygonids from the Amazon basin and described the structural asymmetry of the ovaries and their relationship
Maria Isabel, da Silva, Maria Inês Braga, de Oliveira, Oscar Tadeu Ferreira, da Costa, Wallice Paxiúba, Duncan   +3 more
openaire   +2 more sources

Maturity-related changes in venom toxicity of the freshwater stingray Potamotrygon leopoldi

Toxicon, 2014
Aquatic venomous animals such as stingrays represent a largely untapped source for venom-based drug development. However, the major challenge for a potential drug development pipeline is the high inter- and intraspecific variability in toxicity and venom composition.
Kim N, Kirchhoff, Ines, Klingelhöfer, Hans-Martin, Dahse, Gertrud, Morlock, Thomas, Wilke   +4 more
openaire   +2 more sources

PRESUMPTIVE DYSGERMINOMA IN AN ORANGE-SPOT FRESHWATER STINGRAY (POTAMOTRYGON MOTORO)

Journal of Zoo and Wildlife Medicine, 2015
A captive-born, 13-yr-old female orange-spot freshwater stingray, (Potamotrygon motoro), presented with an acute caudodorsal swelling. Ultrasonography revealed an intracoelomic mass of mixed echogenicity containing fluid pockets. The ray was euthanatized and gross postmortem examination confirmed the presence of a fluid-filled coelomic mass in the ...
Yousuf S, Jafarey, Ric A, Berlinski, Christopher S, Hanley, Michael M, Garner, Matti, Kiupel   +4 more
openaire   +2 more sources

A hyaluronidase from Potamotrygon motoro (freshwater stingrays) venom: Isolation and characterization

Toxicon, 2008
Freshwater stingrays (Potamotrygon motoro) are known to cause human accidents through a sting located in its tail. In the State of Goiás, this accident happens especially during the fishing season of the Araguaia River. The P. motoro venom extracted from the sting presented hyaluronidase activity.
Marta R, Magalhães, Nelson Jorge, da Silva, Cirano J, Ulhoa   +2 more
openaire   +2 more sources

Spine Replacement in a Freshwater Population of the Atlantic Stingray, Dasyatis sabina

Copeia, 1997
Most rays in the order Myliobatiformes possess a hardened spine or barb near the base of the tail (Bigelow and Schroeder, 1953; Halstead et al., 1955; Halstead, 1970). The spine is composed of an inner core of vasodentine and a thin outer layer of enamel-like material.
Amesbury, Elena, Snelson, Franklin F.
openaire   +2 more sources