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Studies on the piezoelectric materials capable of efficiently outputting high electrostrains at low electric fields are driven by the demand for precise actuation in a wide range of applications. Large electrostrains of piezoceramics in operation require high driving fields, which limits their practical application due to undesirable nonlinearities and high energy consumption. Herein, a strategy is developed to enhance the electrostrains of piezoceramics while maintaining low hysteresis by incorporating lead magnesium niobate relaxors into lead zirconate titanium at the morphotropic phase boundary. An ultrahigh inverse piezoelectric coefficient d 33 * of 1380 pm/V with a reduced hysteresis of 11.5% is achieved under a low electric field of 1 kV/mm, outperforming the major lead-based piezoelectric materials. In situ synchrotron X-ray diffraction and domain wall dynamics characterization with sub-microsecond temporal resolution reveal that the outstanding performances originate from facilitated domain wall movement, which in turn is due to reduced lattice distortion and miniaturized domain structures. These findings not only address the pending challenges of effective actuation under reduced driving conditions but also lay the foundation for a more systematic approach to exploring the origin of large electrostrains. The authors develop an application-oriented low-field actuating piezoceramic via relaxor substitution. Their in situ synchrotron XRD analysis along with domain wall dynamics characterization reveals the mechanisms of outstanding performance. [ABSTRACT FROM AUTHOR]

A new cyprinid fish, Opsariichthys rubriventris sp. nov., is described from the Xizhijiang River, a tributary of the Pearl River basin in Huizhou City, Guangdong Province, southern China. The species is distinguished from all other congeners by the following combination of characters: predorsal scales 13–14; lower jaw projecting slightly beyond upper jaw; cheek with two mainly longitudinal rows of tubercles; and lower jaw, belly, pectoral fin, and anterior margin of anal fin in adult males being reddish-orange. The principal component analysis result of the morphological data indicated that O. rubriventris sp. nov. could be clearly distinguished fromfour other congeners. The phylogenetic analysis conducted in this study, utilizing both Maximum Likelihood (ML) and Bayesian Inference (BI) methods, supported the monophyly of the novel species O. rubriventris sp. nov. at the species level. Additionally, the genetic distance analysis revealed that O. rubriventris sp. nov. exhibits a genetic distance ranging from 0.14 to 0.16 with its congeneric species, further affirming its taxonomic status. [ABSTRACT FROM AUTHOR]

Background: Kurixalus lenquanensis Yu, Wang, Hou, Rao and Yang, 2017 was originally described, based on 14 adult male specimens from Lengquan Village, Mengzi, Yunnan, China. So far, this species is known only from south-eastern Yunnan and information on females of this species is not available. During the field surveys in 2023, two Kurixalus specimens (one female and one male) were collected from central eastern Yunnan (Shilin, Kunming, Yunnan, China). These two specimens were confirmed to be K. lenquanensis by molecular phylogenetic analyses, based on 16S rRNA sequences. New information: A female specimen of K. lenquanensis is described for the first time and morphological variation amongst populations of this species is provided. The diagnosis and distribution of this species are updated. [ABSTRACT FROM AUTHOR]

Opsariichthys iridescens sp. nov. is described from the Qiantang and Oujiang rivers in Zhejiang Province and a tributary of the Yangtze River adjacent to the Qiantang River. It is distinguished from congeners by the following combination of morphological features: no obvious anterior notch on the tip of the upper lip; 45–52 lateral-line scales; 18–21 pre-dorsal scales; two rows of pharyngeal teeth; a maxillary extending to or slightly beyond the vertical anterior margin of the orbit in adult males; a pectoral fin extending to the pelvic fin in adult males; nuptial tubercles on the cheeks and lower jaw of males, which are usually united basally to form a plate; uniform narrow pale pink cross-bars on trunk and two widening significantly on caudal peduncle. Its validity was also supported by its distinct Cyt b gene sequence divergence from all congeners and its monophyly recovered in a Cyt b gene-based phylogenetic analysis. [ABSTRACT FROM AUTHOR]

Two new species of the genus Triplophysa from southwestern Guizhou Province, China, are described. These are Triplophysa ziyunensis Wu, Luo, Xiao & Zhou, sp. nov. and Triplophysa yaluwang Lan, Liu, Zhou & Zhou, sp. nov. from Maoying Town, Ziyun County, Guizhou Province, China. Triplophysa ziyunensis Wu, Luo, Xiao & Zhou, sp. nov. is distinguished from other hypogean species of the genus Triplophysa by having a combination of the following characteristics: body naked, scaleless, pigmented markings on surface of body, except ventral; eyes reduced, diameter 2.4–4.9% of head length; pelvic-fin tip extending to anus; tip of pectoral fin not reaching pelvic fin origin; anterior and posterior nostrils closely set, with anterior nostril elongated to a barbel-like tip; tip of outrostral barbel extending backward, not reaching anterior margin of the eye; lateral line complete; posterior chamber of air bladder degenerated; and fin differences. Triplophysa yaluwang Lan, Liu, Zhou & Zhou, sp. nov. is distinguished from other hypogean species of the genus Triplophysa by having a combination of the following characteristics: body naked, scaleless, with irregular pale and dark brownish brown markings, except ventrally; eyes reduced, diameter 4.6–6.1% of head length; pelvic-fin tip reaching anus; tip of pectoral fin not reaching to pelvic fin origin; anterior and posterior nostrils closely set, with anterior nostril elongated to a barbel-like tip; tip of outrostral barbel extending backward, not reaching to anterior margin of the eye; lateral line complete; posterior chamber of air bladder degenerated; and fin differences. Mitochondrial Cyt b revealed relatively small genetic differences, 1.4–2.0%, between the two new species and close relatives. Nuclear gene RAG1 indicated that the two new species possessed unique haplotypes with multiple linking mutations. This study emphasizes the importance of utilizing nuclear genes to identify new species in rapidly speciation cave species, with small genetic differences due to mitochondrial introgression occurring interspecies. [ABSTRACT FROM AUTHOR]

This study describes a new species, Sinocyclocheilus xiejiahuai sp. nov., discovered within a cave located in Hongguo Town, Panzhou City, Guizhou Province, southwestern China, with the type locality in the Nanpanjiang River basin. Phylogenetic trees reconstructed based on mitochondrial genes show that the new species represents an independent evolutionary lineage with large genetic differences, 1.9%–13.8% in mitochondrial Cyt b, from congeners. Morphologically, this species can be differentiated from the 79 species currently classified under the genus Sinocyclocheilus by several characteristics: absence of horn-like structures and indistinct elevation at the head-dorsal junction, absence of irregular black markings on the body lateral and scaleless, eyes large, eye diameter 13% of head length, dorsal-fin rays, iii, 6½, last unbranched ray strong, with serrations along posterior margin, pectoral-fin rays, i, 13, anal-fin rays, iii, 5, pelvic-fin rays, i, 7, lateral line pores 74, gill rakers well developed, nine on first gill arch, pectoral fins short, tip not reaching to pelvic-fin origin. The number of Sinocyclocheilus species has been increased from 79 to 80 since the description of this new species. [ABSTRACT FROM AUTHOR]

Tachysurus wuyueensis, new species, is described from the Qiantang-Jiang Basin, situated in Suichang County, Zhejiang Province and Xiuning County, Anhui Province, southeast China. The coastal basin drains into the East China Sea. The new species belongs to the T. pratti-T. truncatus group within the genus Tachysurus defined by having a smooth anterior margin of the pectoral-fin spine, short maxillary barbels not extending beyond the base of the pectoral-fin spine, short dorsal spine not exceeding two thirds of head length and an emarginated caudal fin. This new species is distinct from all other species of this group, Tachysurus pratti (Gunther, 1892), T. truncatus (Regan 1913), T. gracilis (Li, Chen & Chan, 2005) and T. brachyrhabdion (Cheng, Ishihara & Zhang, 2008), in having a shorter prepelvic body (length 40.0–46.4% of SL vs. 45.8–54.8%). It further differs from T. pratti, T. truncatus and T. gracilis in having more vertebrae (45–47 vs. 37–44) and more anal fin rays (21–25 vs. 14–20), from T. brachyrhabdion in having a more slender body (depth 10.1–13.5% of HL vs. 13.1–17.6%). Molecular phylogeny, based on the mitochondrial cytochrome b (cyt. b) gene confirms the validity of T. wuyueensis and the T. pratti-T. truncatus group. Furthermore, this study addresses the diagnostic traits distinguishing the T. pratti-T. truncatus group from the T. tenuis-T. crassilabris group which have historically been treated as a single species group due to morphological similarities. [ABSTRACT FROM AUTHOR]