The white-edge freshwater whip ray Himantura signifer is ammonotelic in freshwater, but retains the capacities of urea synthesis and ureosmotic osmoregulation to survive in brackish water. The first objective of this study was to examine whether exposure to brackish water would lead to increases in food intake, and/or conservation of nitrogen in H. signifer upon daily feeding. Results obtained ...

Most batoids have a unique swimming mode in which thrust is generated by either oscillating or undulating expanded pectoral fins that form a disc. Only one previous study of the freshwater stingray has quantified three-dimensional motions of the wing, and no comparable data are available for marine batoid species that may differ considerably in their mode of locomotion. Here, we investigate thr...

Three new species of Monocotyle were found on the gills of the coachwhip stingray, Himantura uarnak (Rajiformes: Dasyatidae) collected at Heron Island, Great Barrier Reef, Australia (23 degrees 27' S, 151 degrees 55 'E). Monocotyle helicophallus new species, Monocotyle multiparous new species and Monocotyle spiremae new species all have a single testis and are distinguished from other described...

Adult stingrays use their ampullary electroreceptors to detect prey and locate mates, but the response properties and function of their electrosensory system in the pre-adult stages are unknown. We examined the response properties of Atlantic stingray (Dasyatis sabina) electrosensory primary afferent neurons through ontogeny to determine whether encoding of electrosensory information changes wi...

Dendromonocotyle lotteri sp. n. is described from the dorsal skin surface of the stingray Himantura gerrardi (Gray) on exhibit in the public aquarium at the Atlantis resort in Dubai. It is differentiated from all other Dendromonocotyle species by the unique morphology of the distal portion of the sclerotised male copulatory organ. Dendromonocotyle lotteri is the second representative in the gen...

1Division of Neurosurgery, Department of Surgery, National University Hospital Singapore 2Neurological Surgery Pte Ltd, Singapore 3Department of Neurosurgery, National Neuroscience Institute, Singapore 4KH Ho Neurosurgery, Mount Elizabeth Medical Centre, Singapore Address for Correspondence: Dr Aaron Foo Song Chuan, Division of Neurosurgery, Department of Surgery, National University Hospital S...

1. According to meta-population models, a superior competitor and a superior disperser can coexist in a patchy environment. The two anemonefishes, a large aggressive Amphiprion clarkii Bennett and a small less-aggressive A. perideraion Bleeker, use the same host anemone Heteractis crispa Ehrenberg on a coral reef, Okinawa, Japan, where most of the hosts disappeared after the coral bleaching in ...

The round stingray, Urobatis halleri, is a viviparous elasmobranch that inhabits inshore, benthic habitats ranging from the western U.S.A. to Panama. The population genetic structure of this species was inferred with seven polymorphic microsatellite loci in samples collected at three sites in coastal southern California, one near Santa Catalina Island, California and one in the eastern Gulf of ...