http://scholars.ntou.edu.tw/handle/123456789/197 2026-04-24T10:08:31Z 2026-04-24T10:08:31Z Ng, Shing-Lai White, William T. Liu, Kwang-Ming Joung, Shoou-Jeng http://scholars.ntou.edu.tw/handle/123456789/26500 2026-03-12T03:36:59Z 2025-01-01T00:00:00Z

標題: Etmopterus westraliensis, a new species of lanternshark (Squaliformes: Etmopteridae) from Western Australia, with redescription of Etmopterus brachyurus 作者: Ng, Shing-Lai; White, William T.; Liu, Kwang-Ming; Joung, Shoou-Jeng 摘要: Etmopterus westraliensis is described as a new species based on six specimens collected from Western Australia, eastern Indian Ocean. The new species is assigned to the Etmopterus lucifer group due to its slender, elongate anterior and posterior branches of the flank markings. It shares the following combination of morphological characters with two congeners, Etmopterus brachyurus and Etmopterus samadiae: dermal denticles hook-like, a naked area present on underside of snout, denticles present on dorsal fins in mature individuals, the origin of flank-marking base anterior to a vertical line through origin of the second dorsal fin, caudal-fin base marking thin and slender and a relatively short posterior caudal-fin marking. The new species differs from E. brachyurus in having a longer caudal-fin base marking, ventral portion of caudal-fin base marking much longer than wide, and differs from E. samadiae in having a longer mouth, different shape of the naked area on underside of snout, thinner posterior branch of flank marking, caudal-fin base marking tip tapering and more monospondylous centra. The new species is also distinguished from E. brachyurus and E. samadiae by the mean genetic distance for the NADH2 gene, that is, 0.028 and 0.040, respectively. E. brachyurus is redescribed here based on the holotype together with additional specimens collected from the northwestern Pacific.

2025-01-01T00:00:00Z Chen, Zheng-Zhe Lin, Hsiang-Ting Chang, Chiao-Yun Adil, Muhammad Tsai, Po-Cheng Kao, Tsung Sheng Chen, Chi Lin, Shih-Yen Shih, Min-Hsiung http://scholars.ntou.edu.tw/handle/123456789/26455 2026-03-12T03:36:45Z 2025-01-01T00:00:00Z

標題: Electrically-Driven 2D Semiconductor Microcavity Laser 作者: Chen, Zheng-Zhe; Lin, Hsiang-Ting; Chang, Chiao-Yun; Adil, Muhammad; Tsai, Po-Cheng; Kao, Tsung Sheng; Chen, Chi; Lin, Shih-Yen; Shih, Min-Hsiung 摘要: 2D monolayered transition-metal dichalcogenides (TMDCs) are promising materials for realizing ultracompact, low-threshold semiconductor lasers. And the development of the electrical-driven TMDC devices is crucial for enhancing the integration potential of practical optoelectronic systems. However, at the current stage, the electrically-driven 2-D TMDC laser has never been realized. Herein, the first electrically-driven 2-D TMDC microcavity laser have been developed. In this device, an alternating current (AC) generates electroluminescence lasing in suspended monolayered WSe2 integrated on a microdisk cavity. The input-output curve, bandwidth narrowing, and second-order coherence is analyzed to confirm the lasing characteristics at room temperature. The realization of the room-temperature AC-driven 2-D TMDC laser establishes a new area of research on electrically pumped compact lasers and is likely to assist with the implementation of diverse TMDC-based practical photonic devices in the future.

2025-01-01T00:00:00Z Yu, Chi-Ju Joung, Shoou-Jeng Hsu, Hua-Hsun Liu, Kwang-Ming Yamaguchi, Atsuko http://scholars.ntou.edu.tw/handle/123456789/26339 2026-03-12T03:36:09Z 2025-01-01T00:00:00Z

標題: Stable Isotope Analysis of Two Filter-Feeding Sharks in the Northwestern Pacific Ocean 作者: Yu, Chi-Ju; Joung, Shoou-Jeng; Hsu, Hua-Hsun; Liu, Kwang-Ming; Yamaguchi, Atsuko 摘要: Understanding the feeding ecology and habitat use of vulnerable shark species is crucial for effective conservation. This study focuses on two large filter-feeding sharks, the megamouth shark (Megachasma pelagios) and whale shark (Rhincodon typus), in Northwestern Pacific waters. Stable isotope analysis (delta 13C and delta 15N) was conducted on white muscle samples (n = 91) of M. pelagios and fin clips (n = 90) of R. typus, collected via large-mesh drift nets and set nets in Taiwanese waters. In this study, we investigated feeding strategies, ontogenetic dietary shifts, habitat use, and isotopic niche variation in both species. For R. typus, the observed positive correlation between delta 13C and delta 15N supports the previously proposed active suction filter feeding, as well as implying both a diet with an increasing proportion of higher trophic level prey and an ontogenetic shift. In contrast, M. pelagios displayed a negative correlation, consistent with a previous study associating such patterns with primary or secondary consumers, further aligning with its reported planktonic prey dominance. Both species had increasing delta 13C with growth, signifying a shift to nutrient-rich habitats. Only R. typus exhibited ontogenetic diet changes (delta 15N). SIBER (Stable Isotope Bayesian Ellipses in R) analysis revealed distinct feeding strategies and habitat use between the two species, potential sexual segregation, and wider isotopic niche widths for males in both species. The findings underscore the importance of considering species-specific behaviors and sex-based differences in conservation strategies.

2025-01-01T00:00:00Z Chen, Chi Wu, Guan-Chung Tseng, Yung-Che Dufour, Sylvie Chang, Ching-Fong http://scholars.ntou.edu.tw/handle/123456789/26238 2026-03-12T03:20:37Z 2025-01-01T00:00:00Z

標題: Evolutionary adaptation of anaerobic and aerobic metabolism to high sulfide and hypoxic hydrothermal vent crab, Xenograpsus testudinatus 作者: Chen, Chi; Wu, Guan-Chung; Tseng, Yung-Che; Dufour, Sylvie; Chang, Ching-Fong 摘要: The vent crab, Xenograpsus testudinatus (xtcrab), is adapted to inhabit shallow-water, high sulfide and hypoxic hydrothermal vent. Our previous study revealed sulfide tolerance of vent xtcrabs which sulfide: quinone oxidoreductase (xtSQR) paralogs aid in sulfide detoxification. However, the mechanisms of how xtcrab adapts to high sulfide-hypoxic conditions in the vent area remain to be explored. In the present study, we tested the tolerance of xtcrab to sulfide-induced hypoxia, and investigated their aerobic and anaerobic responses in situ and in the laboratory. Comparisons were made to a non-vent, intertidal species, Thranita danae (tdcrab). We analyzed the several factors related to aerobic metabolism (SQR, cytochrome c [CYTC], complex IV [COXIV]), the product of anaerobic metabolism (hemolymph lactate levels) and glucose levels. Our results showed a higher survival tolerance to hypoxia of xtcrabs than tdcrabs. Hemolymph lactate levels increased more rapidly in xtcrabs than tdcrabs exposed to experimental hypoxia, revealing a rapid induction of anaerobic metabolism in hypoxic xtcrabs. Lactate measurement in xtcrabs returned from aquaria to original capture sites (vent habitats), further assessed the remarkable ability of xtcrabs to rapidly switch on and off their anaerobic metabolism. To assess aerobic metabolism, long-term exposure of xtcrabs to hydrothermal vent habitat increased gill xtCYTC transcripts and protein levels together with steadily enzymatic activity of COXIV. This revealed ability of xtcrabs to maintain functional capacity of aerobic respiration in hypoxia. Phylogenetic analysis showed that xtSQR paralogs in xtcrabs were more distant compared to tdSQR paralogs in tdcrabs. The increase of transcripts and enzymatic activity of gill xtSQR, and co-localization of xtSQR and xtCYTC also contribute to maintain aerobic metabolism by preventing sulfide toxicity on mitochondrial respiratory function. Overall, our study suggests that multiple strategies including detoxification of sulfide by gill xtSQR, and a quick/dynamic switch between aerobic and anaerobic metabolisms may play important roles in the metabolic adaptations of xtcrabs to extreme hydrothermal vent environment.

2025-01-01T00:00:00Z