The Plagiostomia : Sharks, skates, and rays / by Samuel Garman ; with seventy-seven plates.

v.36 (1913) text

The Plagiostomia : Sharks, skates, and rays / by Samuel Garman ; with seventy-seven plates.

v.36 (1913) plates

Prevalência de hemogregarina em arraias de água doce (Potamotrygonidae) da região norte, com descrição de uma nova espécie de gênero

Pós-graduação em Biologia Geral e Aplicada - IBB

Nuclear-follower foraging associations among Characiformes fishes and Potamotrygonidae rays in clean waters environments of Teles Pires and Xingu rivers basins, Midwest Brazil

Por meio de observações sub e supra-aquáticas foram registradas associações alimentares do tipo nuclear-seguidor entre três espécies de peixes characiformes - Chalceus epakros, Hemiodus semitaeniatus e Hemiodus unimaculatus - e uma espécie de raia de água doce - Potamotrygon orbignyi - nas bacias dos rios Teles Pires e Xingu, no Centro-Oeste do Brasil. Os peixes teleósteos foram observados seguindo as raias quando estas revolviam o substrato à procura de invertebrados, formando discretas nuvens de sedimento. Essas situações atraíram os peixes que se aproximaram das raias para se alimentar de pequenas presas e outros tipos de alimentos expostos desta forma. Esse é um típico exemplo de relação comensal onde um participante é beneficiado enquanto o outro não é prejudicado e representa o segundo registro na literatura de associação alimentar do tipo nuclear-seguidor entre raias potamotrigonídeas e peixes teleósteos, demonstrando o potencial de estudos naturalísticos para a descoberta de novas interações envolvendo espécies de peixes de água doce.

The more stirring the better: cichlid fishes associate with foraging potamotrygonid rays

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Nuclear-follower foraging associations among Characiformes fishes and Potamotrygonidae rays in clean waters environments of Teles Pires and Xingu rivers basins, Midwest Brazil

Por meio de observações sub e supra-aquáticas foram registradas associações alimentares do tipo nuclear-seguidor entre três espécies de peixes characiformes - Chalceus epakros, Hemiodus semitaeniatus e Hemiodus unimaculatus - e uma espécie de raia de água doce - Potamotrygon orbignyi - nas bacias dos rios Teles Pires e Xingu, no Centro-Oeste do Brasil. Os peixes teleósteos foram observados seguindo as raias quando estas revolviam o substrato à procura de invertebrados, formando discretas nuvens de sedimento. Essas situações atraíram os peixes que se aproximaram das raias para se alimentar de pequenas presas e outros tipos de alimentos expostos desta forma. Esse é um típico exemplo de relação comensal onde um participante é beneficiado enquanto o outro não é prejudicado e representa o segundo registro na literatura de associação alimentar do tipo nuclear-seguidor entre raias potamotrigonídeas e peixes teleósteos, demonstrando o potencial de estudos naturalísticos para a descoberta de novas interações envolvendo espécies de peixes de água doce.

Quantification of drag and lift imposed by pop-up satellite archival tags and estimation of the metabolic cost to cownose rays (Rhinoptera bonasus)

The recent development of the pop-up satellite archival tag (PSAT) has allowed the collection of information on a tagged animal, such as geolocation, pressure (depth), and ambient water temperature. The success of early studies, where PSATs were used on pelagic fishes, has spurred increasing interest in the use of these tags on a large variety of species and age groups. However, some species and age groups may not be suitable candidates for carrying a PSAT because of the relatively large size of the tag and the consequent energy cost to the study animal. We examined potential energetic costs to carrying a tag for the cownose ray (Rhinoptera bonasus). Two forces act on an animal tagged with a PSAT: lift from the PSATs buoyancy and drag as the tag is moved through the water column. In a freshwater flume, a spring scale measured the total force exerted by a PSAT at flume velocities from 0.00 to 0.60 m/s. By measuring the angle of deflection of the PSAT at each velocity, we separated total force into its constituent forces — lift and drag. The power required to carry a PSAT horizontally through the water was then calculated from the drag force and velocity. Using published metabolic rates, we calculated the power for a ray of a given size to swim at a specified velocity (i.e., its swimming power). For each velocity, the power required to carry a PSAT was compared to the swimming power expressed as a percentage, %TAX (Tag Altered eXertion). A %TAX greater than 5% was felt to be energetically significant. Our analysis indicated that a ray larger than 14.8 kg can carry a PSAT without exceeding this criterion. This method of estimating swimming power can be applied to other species and would allow a researcher to decide the suitability of a given study animal for tagging with a PSAT.

Developmental characters of Psettina Iijimae (Jordan and Starks), bothid flat fishes - Pisces

Post larval stages of Psettina Iijimae ranging from 1.8 mm NL to 44.6 mm SL collected during Naga Expedition and International Indian Ocean Expedition (IIOE) are described. The characteristics which help to identify larval stages of Psettina are: the presence of pigmented urohyal appendage in early stages which is progressively reduced during flexion stages and which disappears in later postflexion stages, the meristics, the spines on urohyal and posterior basipterygial processes and the absence of spines on cleithra. The P. iijimae can be distinguished by the presence of spines on the median fin rays which differentiate near the baseosts along the dorsal and ventral body wall much before the fin rays. The larvae of P.iijimae were more abundant in the Gulf of Thailand compared to South China Sea and Indian Ocean.

Distribution of vitamin B-12 in some fishes and marine invertebrates

Distribution of vitamin B-12 in the skeletal muscle of several marine and fresh water fish and marine invertebrates are reported. The vitamin B-12 content of white muscle of various fish ranges between 0.05 and 1.5 micrograms. The elasmobranch fish, such as sharks and rays, has a lower levels of vitamin B-12. The distribution of vitamin B-12 in the red muscle, heart, brain and liver of various fish is also shown. Content in red muscle varies between 3 and 22 micrograms, averaging 8 micrograms. The values show that the heart is a rich source of vitamin B-12. Internal organs are also rich in vitamin B

Identification and distribution of cartilaginous fishes of the Persian Gulf (Bushehr Province waters)

Class Condrichthyes consist of two sub-classes: Holocehali and. Elasmobranchii, the second one are more divers and has more importance. Selachimorpha (sharkes) and Batidoidimorpha (rays and skates) are two super-order of Elasmobranchii, which they have crucial role in ecological balance in marine ecosystmes. Except few cases, most of sharks and rays (rays and skates) are not well identified, so a lot of works need to be done in this regards. The area of study is located between 49°, 35' and 52°, 33' E and between 27°, 21' and 30°, 02' N in depth of 7 to 78 in. Study were conducted diuring August 1998, September 1999. Samples were taken during 3 sea cruises from 70 bottom trawl net. All sharks and batoid fishes were identified based on biometric specifications (weight, total, length and sexuality for both group and extra biometric specifications, disc width, disc length, and tail length only for, batoid fishes). The 1140 specimens of batoid fishes identified belonged to 6 families, and 18 species. 3 new species were identified, they are Himantura sp.1 and Himantura sp.2 belonged to Dasyatidae family and Rhinobatos sp. belonged to Rhinobatidae Familiy. It needs more works and more adaquate ducuments for cl.earfing scientific names of these species. The 275 specimens of sharks identified belonged to 6 families and 10 species. Chiloscyllium sp. belonged to Hemiscylliidae, family as a new species was identified.

DNA barcoding taxonomy and diversity of the Mediterranean sharks and rays

Elasmobranchs are an important by-catch of commercial fisheries targeting bony fishes. Fisheries targeting sharks are rare, but usually almost all specimen bycatched are marketed. They risk extinction if current fishing pressure continues (Ferretti et al., 2008). Accurate species identification is critical for the design of sustainable fisheries and appropriate management plans, especially since not all species are equally sensitive to fishing pressure (Walker & Hislop 1998). The identification of species constitutes the first basic step for biodiversity monitoring and conservation (Dayrat B et al., 2005). More recently, mtDNA sequencing has also been used for species identification and its use has become widespread under the DNA Barcode initiative (e.g. Hebert et al. 2003a, 2003b; Ward et al. 2005, 2008a; Moura et al 2008; Steinke et al. 2009). The aims of this work were: 1) identify sharks and skates species using DNA barcode; 2) compare species of different provenance; 3) use DNA barcode for misidentified species. Using DNA barcode 15 species of sharks (Alopias vulpinus, Centrophorus granulosus, Cetorhinus maximus, Dalatias licha, Etmopterus spinax, Galeorhinus galeus, Galeus melastomus, Heptranchias perlo, Hexanchus griseus, Mustelus mustelus, Mustelus punctulatus, Oxynotus centrina, Scyliorhinus canicula Squalus acanthias, Squalus blainville), 1 species of chimaera (Chimaera monstrosa) and 21 species of rays/skayes (Dasyatis centroura, Dasyatis pastinaca, Dasyatis sp., Dipturus nidarosiensis, Dipturus oxyrinchus, Leucoraja circularis, Leucoraja melitensis, Myliobatis aquila, Pteromylaeus bovinus, Pteroplatytrygon violacea, Raja asterias, Raja brachyura, Raja clavata, Raja miraletus, Raja montagui, Raja radula, Raja polystigma, Raja undulata, Rostroraja alba, Torpedo marmorata, Torpedo nobiliana, Torpedo torpedo) was identified.

Molecular studies suggest that cartilaginous fishes have a terminal position in the piscine tree

The Chondrichthyes (cartilaginous fishes) are commonly accepted as being sister group to the other extant Gnathostomata (jawed vertebrates). To clarify gnathostome relationships and to aid in resolving and dating the major piscine divergences, we have sequenced the complete mtDNA of the starry skate and have included it in phylogenetic analysis along with three squalomorph chondrichthyans—the common dogfish, the spiny dogfish, and the star spotted dogfish—and a number of bony fishes and amniotes. The direction of evolution within the gnathostome tree was established by rooting it with the most closely related non-gnathostome outgroup, the sea lamprey, as well as with some more distantly related taxa. The analyses placed the chondrichthyans in a terminal position in the piscine tree. These findings, which also suggest that the origin of the amniote lineage is older than the age of the oldest extant bony fishes (the lungfishes), challenge the evolutionary direction of several morphological characters that have been used in reconstructing gnathostome relationships. Applying as a calibration point the age of the oldest lungfish fossils, 400 million years, the molecular estimate placed the squalomorph/batomorph divergence at ≈190 million years before present. This dating is consistent with the occurrence of the earliest batomorph (skates and rays) fossils in the paleontological record. The split between gnathostome fishes and the amniote lineage was dated at ≈420 million years before present.

Trichodinids (Ciliophora : Trichodinidae) from native and exotic Australian freshwater fishes

There are very few data on trichodinids of freshwater fishes in Australia. 2003 fishes were surveyed across Eastern Australia to investigate the diversity of trichodinids present, to determine which species have been introduced with exotic fishes and to determine the extent to which these species have crossed into native fish Populations. Twenty-one putative trichodinid species were recovered from the 33 fish species examined. Trichodina heterodentata, T. mutabilis and T. reticulata were the exotic species recovered regularly; a single specimen matched a fourth exotic species, T acuta. All four exotic species are redescribed from Australian material. Trichodina heterodentata was recorded from 17 species of fishes, 15 of which were new host records; this species is identified as one of emerging importance in fish parasitology and a list of its known hosts is presented. Two new native species are also described based on silver stained specimens: T cribbi sp. n. from Hypseleotris galii, H. klunzingeri, and Hypseleotris sp. 5; and T. bassonae sp. n. from Selenotoca multifasciata. Trichodina cribbi is characterised by a large circular central inclusion and approximately 28 denticles, which have a blade length slightly greater than the ray length. Trichodina bassonae is characterised by a small, round, central inclusion and approximately 25 denticles, which have straight, non tapering rays that are in line with the leading edge of the denticle blade. It is estimated that the Australian trichodinid fauna may include up to 150 as yet undescribed species and represents a major source of unexplored biodiversity.

Unwrapping an ancient Egyptian mummy using x-rays

This article describes a project to unwrap an ancient Egyptian mummy using X-ray computed tomography (CT). About 600 X-ray CT images were obtained through the mummified body of a female named Tjetmutjengebtiu (or Jeni for short), who was a singer in the great temple of Karnak in Egypt during the 22nd dynasty (c. 945-715 BC). The X-ray CT images reveal details of the remains of body organs, wrappings and jewellery. 3D reconstructions of Jeni’s teeth suggest that she was probably only around 20 years old when she died, although the cause of death cannot be ascertained from the CT scans. The CT images were used to build a 3D model of Jeni’s head which enabled an artist to paint a picture of what Jeni may have looked like during life. A PowerPoint presentation and movie clips are provided as supplementary material that may be useful for teaching.