The snailfish Osteodiscus abyssicola sp. nov. is described from a single specimen collected off the Pacific coast of Hokkaido, northern Japan, at a depth of 4,6714,744 m.
View Article and Find Full Text PDFBiochem Biophys Res Commun
November 2021
The lantern shark genus Etmopterus contains approximately 40 species of deep-sea bioluminescent cartilaginous fishes. They emit blue light mainly from the ventral body surface. The biological functions of this bioluminescence have been discussed based on the luminescence patterns, but the bioluminescence mechanism remains uncertain.
View Article and Find Full Text PDFThree snailfish species of Careproctus (Cottoidei: Liparidae), including two new species, are described from the deep Pacific Ocean off northern Honshu Island, Japan. Careproctus cyanogladius sp. nov.
View Article and Find Full Text PDFA new species of softnose skate (Arhynchobatidae), Bathyraja sexoculata Misawa, Orlov, Orlova, Gordeev and Ishihara is described on the basis of five specimens collected from off the east coast of Simushir Island, Kuril Islands, located in the western North Pacific. The specimens conformed to the genus Bathyraja by having the anteriormost pectoral-fin skeleton almost reaching the snout tip, and a slender unsegmented rostral cartilage. Within Bathyraja, the new species belongs to the subgenus Arctoraja (currently with four valid species) due to the relatively short tail (79-86% of disc width), high count of predorsal caudal vertebrae (more than 86), and large strong nuchal and scapular thorns.
View Article and Find Full Text PDFA new codlet species is described from Japan, Taiwan, Indonesia and Australia. It is distinguished from its congeners by having a pointed snout extending beyond jaws, a stripe of black dots above anal-fin base, a black vertical band on caudal-fin base, and the following combination of characters: ventral surface of head and abdomen devoid of melanophores; ventral portion of abdominal vertebrae with a pointed parapophysis and a blunt ventral post-zygapophysis; peritoneum, pyloric caeca, and intestine pale; dorsal-fin rays 46-52; anal-fin rays 47-55; pectoral-fin rays 15-17; principal caudal-fin rays 12‒14; caudal vertebrae 35‒39; total vertebrae 50-54. Furthermore, as a result of this study, Bregmaceros pescadorus Shen described from southwestern Taiwan is herein recognized as a junior synonym of Bregmaceros nectabanus Whitley.
View Article and Find Full Text PDFBregmaceros retrodorsalis sp. nov., a new codlet species is described based on specimens from shallow to deep waters off Japan and Melanesia.
View Article and Find Full Text PDFIn this study, we aim to evaluate the comprehensive geometric accuracy of proton rotating gantries by performing an end-to-end test using a cone-shaped scintillator screen detector, known as XRV-124. The XRV-124 comprises a cone-shaped sheet-like scintillator and charge-coupled device camera that detects the scintillation light. First, the results of the Winston-Lutz and end-to-end XRV-124 tests performed on a conventional linear accelerator were compared to confirm the reliability of the XRV-124, and the snout position dependency of the geometric accuracy was evaluated for the proton rotating gantry as a pre-verification process.
View Article and Find Full Text PDFThis study aimed to evaluate the influence of change in respiratory motion on matchline (ML) and reduction of the effect by increasing ML levels of field matching technique in passive scattering proton therapy for esophageal cancer. To evaluate the influence of respiratory motion in terms of stability, we measured relative dose around ML using a respiratory motion phantom. The relative error was -0.
View Article and Find Full Text PDFA new species of argentinid fish, Glossanodon macrocephalus Bineesh Endo, from the Arabian Sea, off the southwestern coast of India, is described on the basis of four specimens (129-164 mm SL). The new species clearly differs from its congeners in the following combination of characters: dorsal-fin rays 10-11; pectoral-fin rays 21-23; anal-fin rays 12-13; pelvic-fin rays 11-12; branchiostegal rays 5; gill rakers on first arch 30-36; vertebrae 47-48; a patch of small conical teeth on middle of lower jaws; predorsal 49-51% SL; prepectoral 36-39% SL; prepelvic 57-58% SL; distance from pelvic to anal-fin origin 26-28% SL; head length 35-39% SL; eye diameter 22-26% HL; snout length 28-30% HL; location of anus immediately anterior to anal-fin origin; broad longitudinal black stripe above lateral line; dark spot on the base to half of pectoral fin; and no teeth on tongue. The new species is a benthopelagic dweller on muddy bottoms in depths of around 300-600 m.
View Article and Find Full Text PDFA new tilefish, Branchiostegus biendong, is described on the basis of three specimens (181-209 mm in standard length [SL]) collected from a local fish market of Quy Nhon on the South China Sea coast of central Vietnam. It can be distinguished from 17 congeners in having the following combination of characters: six diagonal scale rows exposed on cheek; cheek scales moderately large (diameter 2.2-2.
View Article and Find Full Text PDFThe aim of this study was to confirm On-Board Imager cone-beam computed tomography (CBCT) using the histogram-matching algorithm as a useful method for proton dose calculation. We studied one head and neck phantom, one pelvic phantom, and ten patients with head and neck cancer treated using intensity-modulated radiation therapy (IMRT) and proton beam therapy. We modified Hounsfield unit (HU) values of CBCT and generated two modified CBCTs (mCBCT-RR, mCBCT-DIR) using the histogram-matching algorithm: modified CBCT with rigid registration (mCBCT-RR) and that with deformable image registration (mCBCT-DIR).
View Article and Find Full Text PDF"Photobacterium mandapamensis" (proposed name) and Photobacterium leiognathi are closely related, phenotypically similar marine bacteria that form bioluminescent symbioses with marine animals. Despite their similarity, however, these bacteria can be distinguished phylogenetically by sequence divergence of their luminescence genes, luxCDAB(F)E, by the presence (P. mandapamensis) or the absence (P.
View Article and Find Full Text PDFThe gene order of mitochondrial genomes (mitogenomes) has been employed as a useful phylogenetic marker in various metazoan animals, because it may represent uniquely derived characters shared by members of monophyletic groups. During the course of molecular phylogenetic studies of the order Gadiformes (cods and their relatives) based on whole mitogenome sequences, we found that two deep-sea grenadiers (Squalogadus modificatus and Trachyrincus murrayi: family Macrouridae) revealed a unusually identical gene order (translocation of the tRNA(Leu (UUR))). Both are members of the same family, although their external morphologies differed so greatly (e.
View Article and Find Full Text PDFA recent preliminary study using complete mitochondrial DNA sequences from 48 species of teleosts has suggested that higher teleostean phylogenies should be reinvestigated on the basis of more intensive taxonomic sampling. As a second step towards the resolution of higher teleostean phylogenies, which have been described as the "(unresolved) bush at the top of the tree," we reanalyzed their relationships using mitogenomic data from 100 purposefully chosen species that fully represented all of the higher teleostean orders, except for the Batrachoidiformes. Unweighted and weighted maximum parsimony analyses were conducted with the data set that comprised concatenated nucleotide sequences from 12 protein-coding genes (excluding 3rd codon positions) and 21 transfer RNA (tRNA) genes (stem regions only) from each species.
View Article and Find Full Text PDF