Himantura pacifica (lat.) Is a poorly studied species of the genus of stingrays -hematures from the family of the caudate - tailed squad of the caudate-like over- order of the rays . They live in the tropical waters of the eastern Pacific. The maximum recorded width of the disk is 60 cm. The pectoral fins of these slopes fuse with the head, forming an oval disk. There are no keels on the caudal stem. Like other caudate-tailed Himantura pacifica, they reproduce by egg-production . Embryos develop in the womb, feeding on the yolk and histotroph [1] .
| Himantura pacifica |
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| No rank : | Bilateral symmetrical |
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Himantura pacifica ( Beebe & Tee-Van , 1941) |
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- Dasyatis pacificus Beebe & Tee-Van, 1941
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For the first time, a new species was scientifically described in 1941 [2] . The species is named by its geographical habitat (Pacific Ocean). Type specimens were collected off the coast of Costa Rica ( ) [3] . In 1999, the validity of the species was called into question [1] .
The species Himantura pacifica and Himantura schmardae are probably closely related. These have morphological similarities, in particular, for both species in the area of the “shoulders” lies a series of spines covered with four radial ridges. Based on the characteristics of the mandibular musculature and articulation, it was suggested that this group of species is more close to the genus of river stingrays of the Potamotrygonidae family than to the group of Indo-Pacific stingrays-hematures [4] . A hypothesis arose on it, according to which Himantura pacifica , Himantura schmardae, and river stingrays descended from the euryhaline ancestors that lived along the northern coast of South America until the formation of the Isthmus of Panama . However, it is doubtful, because, based on parasitological data, river stingrays are closely related to the Pacific genus Urobatis [4] .
Himantura pacifica inhabit the Pacific coast of Central America from Oaxaca , Mexico , to Costa Rica, as well as around the Galapagos Islands . These slopes are found offshore in shallow water on soft ground. Swim in brackish water [4] [5] .
The pectoral fins of these slopes fuse with the head, forming an oval disk, the length slightly exceeds the width. The front edge is slightly curved and forms an obtuse angle, the tip of the snout protrudes slightly beyond the edges of the disk. Behind the eyes are sprays . On the ventral surface of the disc are 5 pairs of gill slits , mouth and nostrils. Between the nostrils lies a flap of skin with a fringed lower edge. Small blunted teeth are staggered and form a flat surface. There are no skin folds on the caudal peduncle. The dorsal surface of the disc and caudal peduncle is densely covered with scales [4] [5] . In the area of “shoulders” lies a series of large plaques covered with radial ridges [4] . On the dorsal surface of the caudal peduncle there is a thin spine connected by ducts with a poisonous gland [1] . The maximum recorded disk width is 60 cm, and the total length is 150 cm [1] .
Like other caudate-tailed Himantura pacifica belongs to ovoviviparous fish. Embryos develop in the womb, feeding on the yolk and histotroph. On these slopes, cestodes Acanthobothroides pacificus and Rhinebothrium geminum parasitize [6] [7] .
The International Union for Conservation of Nature has not yet assessed the conservation status of the species.