Redescription of the hispidoberycid, Hispidoberyxambagiosus Kotlyar, 1981 from Taiwan, with comments on its morphology (Beryciformes, Stephanoberycoidei, Hispidoberycidae).

A rare spiny-scale pricklefish, Hispidoberyxambagiosus Kotlyar, 1981, is redescribed based on four specimens collected from Taiwan. Their sampling locality represents the northernmost record of the family, which extends the family's distribution from the eastern Indian Ocean and the South China Sea to northeastern Taiwan in the northwestern Pacific Ocean. A detailed description of these specimens and the first description of its sagittal otoliths are provided. In addition, the specimens are compared with other known specimens. Intraspecific variation of some morphological characters are discussed.

Ocean temperature drove changes in the mesopelagic fish community at the edge of the Pacific Warm Pool over the past 460,000 years.

Field observations and theoretical modeling suggest that ongoing anthropogenic ocean warming will lead to marine ecosystem degradation. Mesopelagic fish are a fundamental component of the pelagic ecosystem, and their role in linking the surface- and deep-ocean ecosystems is essential for the biological carbon pump. However, their response to a warmer ocean is unconstrained because of data scarcity. Using extraordinarily well-preserved fish otoliths, we reconstruct a continuous mesopelagic fish community record in the Pacific Warm Pool region over 460,000 years. Fish production and diversity followed hump-shaped temperature gradients, with lower tipping point temperatures for the diversity than the production by ~1.5° to 2.0°C. During warmer-than-present interglacial periods, both production and diversity declined drastically. Our findings imply that the temperature-sensitive mesopelagic fish community at the southwestern margin of the Pacific Warm Pool, and possibly other hydrographically similar regions, may be especially affected if ocean warming continues unabated in the future.

Record of the Amarsipa fish (Family Amarsipidae) from Pratas Island, South China Sea.

Two specimens of the rare Amarsipa fish, Amarsipus carlsbergi, were collected from Pratas Island in the northern South China Sea. They represent the first record of Taiwanese EEZ and fill the distribution gap in the northwestern Pacific Ocean between Japan (East China Sea) and Vietnam. The two specimens were identified based on their diagnostic characteristics, including no pharyngeal sacs, a pelvic fin well in front of the pectoral fin, a slender body and other morphology. Detailed data and descriptions of these two specimens, including a description of otolith morphology, are provided.

First Skeletal Fossil Record of the Red Seabream Pagrus major (Sparidae, Perciformes) from the Late Pleistocene of Subtropical West Pacific, Southern Taiwan.

Fish fossils are only occasionally found in Taiwan, and such fossils are rarely appropriately analyzed and described. Despite their sparse records, several Plio-Pleistocene localities rich in marine organisms have yielded well-preserved specimens, potentially providing insight into the rarely identified fish fauna in the tropical-subtropical West Pacific. We describe a sandstone nodule containing fish skeletons from the Late Pleistocene Szekou Formation in southern Taiwan. The specimen includes nearly complete left jaws, fragmentary right jaws, and part of the anterior body. The distinct dentition of the specimen suggests it to be a member of Sparidae family. Further morphological analysis based on dentition and a comparison with 153 recent specimens belonging to 14 sparid species in the area enabled us to assign the fossil to the species Pagrus major. We found that the characteristic sparid tooth patterns are useful in generic determination, at least in Taiwan. The occurrence of the specimen is the first evidence of P. major in the region. Finally, the specialized tooth pattern and the estimated size indicate that the fish was a middle-to-top predator that fed on small fish and invertebrates in a neritic lagoonal environment.

A previously overlooked, highly diverse early Pleistocene elasmobranch assemblage from southern Taiwan.

The Niubu fossil locality in Chiayi County, southern Taiwan is best known for its rich early Pleistocene marine fossils that provide insights into the poorly understood past diversity in the area. The elasmobranch teeth at this locality have been collected for decades by the locals, but have not been formally described and have received little attention. Here, we describe three museum collections of elasmobranch teeth (n = 697) from the Liuchungchi Formation (1.90-1.35 Ma) sampled at the Niubu locality, with an aim of constructing a more comprehensive view of the past fish fauna in the subtropical West Pacific. The assemblage is composed of 20 taxa belonging to nine families and is dominated by Carcharhinus and Carcharodon. The occurrence of †Hemipristis serra is of particular importance because it is the first Pleistocene record in the area. We highlight high numbers of large Carcharodon carcharias teeth in our sample correlating to body lengths exceeding 4 m, along with the diverse fossil elasmobranchs, suggesting that a once rich and thriving marine ecosystem in an inshore to offshore shallow-water environment during the early Pleistocene in Taiwan.

Redescription of Lophiodes lugubris (Alcock, 1894), with the largest record of Lophiodes triradiatus (Lloyd, 1909) from the South China Sea (Lophiiformes: Lophiidae).

A rare lophiid anglerfish species, Lophiodes lugubris, is redescribed on the basis of two syntypes and non-types. It is unique in having only 4 dorsal-fin spines, among the congeners. Examination of specimens reveals this species is widespread in the Indian Ocean and a specimen newly collected from off Dongsha Island represents the first record of the South China Sea, as well as the Pacific Ocean. A largest record specimen of Lophiodes triradiatus known to date is also documented. Comments on the morphology of sagittal otoliths taken from Taiwanese lophiids are provided.

Dicyano-Imidazole: A Facile Generation of Pure Blue TADF Materials for OLEDs.

A series of dicyano-imidazole-based molecules with thermally activated delayed fluorescence (TADF) properties were synthesized to obtain pure blue-emitting organic light-emitting diodes (OLEDs). The targeted molecules used dicyano-imidazole with a short-conjugated system as the electron acceptor to strong intermolecular π-π interactions, and provide a relatively shallow energy level of the lowest unoccupied molecular orbital (LUMO). The cyano group was selected to improve imidazole as an electron acceptor due to its prominent electron-transporting characteristics. Four different electron donors, that is, 9,9-dimethyl-9,10-dihydroacridine (DMAC), 10H-spiro(acridine-9,9'-fluoren) (SPAC), and 9,9-diphenyl-9,10-dihydroacridine (DPAC), were used to alternate the highest occupied molecular orbital (HOMO) energy level to tune the emission color further. The crowded molecular structure in space makes the electron donor and acceptor almost orthogonal, reducing the energy gap (ΔEST ) between the first excited singlet (S1 ) and the triplet (T1 ) states and introducing significant TADF property. The efficiencies of the blue-emissive devices with imM-SPAC and imM-DMAC obtained in this work are the highest among the reported imidazole-based TADF-OLEDs, which are 13.8 % and 13.4 %, respectively. Both of Commission Internationale de l'Eclairage (CIE) coordinates are close to the saturated blue region at (0.17, 0.18) and (0.16, 0.19), respectively. Combining these tailor-made TADF compounds with specific device architectures, electroluminescent (EL) emission from sky-blue to deep-blue could be achieved, proving their great potential in EL applications.

Age and growth of Palaeoloxodon huaihoensis from Penghu Channel, Taiwan: significance of their age distribution based on fossils.

Dental material attributed to Palaeoloxodon huaihoensis from the Middle to Late Pleistocene were recovered over decades from the Penghu Channel during commercial fisheries activities. The National Museum of Nature Science (NMNS) has a collection of such dental material, which differs in size and morphology and likely represents ontogenetic variation and growth trajectory of various age groups of P. huaihoensis. However, little is known regarding age determination. By using length of dental material, enamel thickness (ET), and plate counts, we established the method to distinguish the age of the species, which is directly derived from the extant African forest elephant Loxodonta africana. When measuring signs of allometric growth, we found that in both the upper and lower jaws, tooth width was correlated negatively with lamellar frequency but positively with ET. In the same age group, the number of lamellae was higher in P. huaihoensis than in L. africana. The reconstructed age distribution indicated no difference in the upper or lower jaw. Notably, within our sample, P. huaihoensis is skewed towards adult and older individuals with median age between 33-34.5 years and differed significantly from that of Mammuthus primigenius in the European Kraków Spadzista site. This age distribution pattern is speculated to be related to the harsh environmental conditions and intense intraspecific competition among P. huaihoensis during the last ice age.

Combinational Approach To Realize Highly Efficient Light-Emitting Electrochemical Cells.

Light-emitting electrochemical cells (LECs) show high technical potential for display and lighting utilizations owing to the superior properties of solution processability, low operation voltage, and employing inert cathodes. For maximizing the device efficiency, three approaches including development of efficient emissive materials, optimizing the carrier balance, and maximizing the light extraction have been reported. However, most reported works focused on only one of the three optimization approaches. In this work, a combinational approach is demonstrated to optimize the device efficiency of LECs. A sophisticatedly designed yellow complex exhibiting a superior steric hindrance and a good carrier balance is proposed as the emissive material of light-emitting electrochemical cells and thus the external quantum efficiency (EQE) is up to 13.6%. With an improved carrier balance and reduced self-quenching by employing the host-guest strategy, the device EQE can be enhanced to 16.9%. Finally, a diffusive layer embedded between the glass substrate and the indium-tin-oxide layer is utilized to scatter the light trapped in the layered device structure, and consequently, a high EQE of 23.7% can be obtained. Such an EQE is impressive and consequently proves that the proposed combinational approach including adopting efficient emissive materials, optimizing the carrier balance, and maximizing the light extraction is effective in realizing highly efficient LECs.

Efficient and Saturated Red Light-Emitting Electrochemical Cells Based on Cationic Iridium(III) Complexes with EQE up to 9.4 .

Solid-state light-emitting electrochemical cells (LECs) have several advantages, such as low-voltage operation, compatibility with inert metal electrodes, large-area flexible substrates, and simple solution-processable device architectures. However, most of the studies on saturated red LECs show low or moderate device efficiencies (external quantum efficiency (EQE) <3.3 %). In this work, we demonstrate a series of five red-emitting cationic iridium complexes (RED1--RED5) with 2,2'-biquinoline ligands and test their electroluminescence (EL) characteristics in LECs. The Commission Internationale de l'Eclairage (CIE) 1931 coordinates for the LECs based on these complexes are all beyond the National Television System Committee (NTSC) red standard point (0.67, 0.33). The maximal EQE of the neat-film RED1-based LECs reaches 7.4 %. The reddest complex, RED3, is doped in the blue-emitting host complex, BG, to fabricate host-guest LECs. The maximal EQE of the host-guest LECs (1 wt % complex RED3) reaches 9.4 %, which is among the highest reported for the saturated red LECs.

Reconstructing reef fish communities using fish otoliths in coral reef sediments.

Little is known about long-term changes in coral reef fish communities. Here we present a new technique that leverages fish otoliths in reef sediments to reconstruct coral reef fish communities. We found over 5,400 otoliths in 169 modern and mid-Holocene bulk samples from Caribbean Panama and Dominican Republic mid-Holocene and modern reefs, demonstrating otoliths are abundant in reef sediments. With a specially-built reference collection, we were able to assign over 4,400 otoliths to one of 56 taxa (35 families) though mostly at genus and family level. Many otoliths were from juvenile fishes for which identification is challenging. Richness (by rarefaction) of otolith assemblages was slightly higher in modern than mid-Holocene reefs, but further analyses are required to elucidate the underlying causes. We compared the living fish communities, sampled using icthyocide, with the sediment otolith assemblages on four reefs finding the otolith assemblages faithfully capture the general composition of the living fish communities. Radiocarbon dating performed directly on the otoliths suggests that relatively little mixing of sediment layers particularly on actively accreting branching coral reefs. All otolith assemblages were strongly dominated by small, fast-turnover fish taxa and juvenile individuals, and our exploration on taxonomy, functional ecology and taphonomy lead us to the conclusion that intense predation is likely the most important process for otolith accumulation in reef sediments. We conclude that otolith assemblages in modern and fossil reef sediments can provide a powerful tool to explore ecological changes in reef fish communities over time and space.

Cationic IrIII Emitters with Near-Infrared Emission Beyond 800†nm and Their Use in Light-Emitting Electrochemical Cells.

Solid-state near-infrared (NIR) light-emitting devices have recently received considerable attention as NIR light sources that can penetrate deep into human tissue and are suitable for bioimaging and labeling. In addition, solid-state NIR light-emitting electrochemical cells (LECs) have shown several promising advantages over NIR organic light-emitting devices (OLEDs). However, among the reported NIR LECs based on ionic transition-metal complexes (iTMCs), there is currently no iridium-based LEC that displays NIR electroluminescence (EL) peaks near to or above 800 nm. In this report we demonstrate a simple method for adjusting the energy gap between the highest-occupied molecular orbital (HOMO) and the lowest-unoccupied molecular orbital (LUMO) of iridium-based iTMCs to generate NIR emission. We describe a series of novel ionic iridium complexes with very small energy gaps, namely NIR1-NIR6, in which 2,3-diphenylbenzo[g]quinoxaline moieties mainly take charge of the HOMO energy levels and 2,2'-biquinoline, 2-(quinolin-2-yl)quinazoline, and 2,2'-bibenzo[d]thiazole moieties mainly control the LUMO energy levels. All the complexes exhibited NIR phosphorescence, with emission maxima up to 850 nm, and have been applied as components in LECs, showing a maximum external quantum efficiency (EQE) of 0.05 % in the EL devices. By using a host-guest emissive system, with the iridium complex RED as the host and the complex NIR3 or NIR6 as guest, the highest EQE of the LECs can be further enhanced to above 0.1 %.