The new species is a member of an apparently monophyletic group within the genus that includes R. flexile, R. walga, R. himanturi, R. burgeri, R. euzeti, R. hawaiiensis, R. urobatidium, R. paratrygoni, R. ditesticulum, R. tetralobatum, R. margaritense, R. biorchidum, and R. spinicephalum. All of these species have bothridia with medial longitudinal septa, a constriction at mid-bothridium, and, ...

Rajiform locomotion is a unique swimming style found in the batoid fishes (skates and rays) in which thrust is generated by undulatory waves passing down the enlarged pectoral fins. We examined the kinematic patterns of fin motion and the motor patterns of pectoral fin muscles driving the locomotor system in the blue-spot stingray Taeniura lymma. Our goals in this study were to determine overal...

L-gulono-γ-lactone oxidase (Gulo) catalyzes the last step of ascorbic acid biosynthesis, which occurs in the kidney of elasmobranchs. This study aimed to clone and sequence gulonolactone oxidase (gulo) from the kidney of the euryhaline freshwater stingray, Himantura signifer, and to determine the effects of acclimation from freshwater to brackish water (salinity 20) on its renal gulo mRNA expre...

Echinocephalus janzeni n. sp. in the stingray, Himantura pacifica, is described from the eastern Pacific Ocean off the coasts of Costa Rica and southern Mexico. On the basis of the presence of 6 postanal caudal papillae, and modified annules anterior to the caudal alae in males, E. janzeni is most similar to Echinocephalus daileyi and Echinocephalus diazi. Specimens of E. janzeni are distinguis...