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Clear species boundaries are crucial for plans and actions on biodiversity conservation. However, morphological similarities among allied species can result in taxonomic difficulties, thus impeding conservation efforts. In China, Cinnamomum japonicumSiebold is a well‐known endangered plant, yet suffers from longstanding taxonomic issues. Here, we explicitly evaluate whether C. japonicum, C. chenii, and C. chekiangense are the same phylogenetic species on the basis of a multi‐individual sampling strategy. We identified three sets of low‐copy orthologous genes from 19 Lauraceae taxa for phylogenetic inferences. Both the concatenation and coalescent‐based phylogenies supported that C. chenii individuals were embedded in the C. japonicum clade, indicating these two taxa are conspecific. Meanwhile, C. chekiangense accessions formed a monophyly which was not sister to C. japonicum. This result, together with the morphological differences that the leaves of C. japonicum are glabrous with a faveolate pattern of venation while those of C. chekiangense have trichomes and inevident lateral veins, led us to consider both as two distinct species. Based on 17 728 neutral single nucleotide polymorphisms (SNPs), the ADMIXTURE analysis suggested that the Chinese C. japonicum populations in Zhoushan Archipelago (=C. chenii) were genetically differentiated from the Japanese and Korean ones. Furthermore, ecological niche modeling predicted that the present distribution area of Chinese C. japonicum is likely to be unsuitable under global warming scenarios. Together with its limited distribution and genetic uniqueness, we recommend that Chinese C. japonicum deserves conservation priorities. [ABSTRACT FROM AUTHOR]

Accurate species delimitation is the key to precise estimation of species diversity and is fundamental to most branches of biology. Unclear species boundaries within species complexes could lead to the underestimation of species diversity. However, species delimitation of species complexes remains challenging due to the continuum of phenotypic variations. To robustly examine species boundaries within a species complex, integrative approaches in phylogeny, ecology, and morphology were applied to the Stewartia sinensis complex (Theaceae) endemic to China. Multispecies coalescent‐based species delimitation using 572 nuclear ortholog sequences (anchored enrichment) supported reciprocal phylogenetic monophyly of the northern lineage (NL) and southern lineage (SL), which were not sister clades. Niche equivalency and similarity tests demonstrated significant climatic niche differentiation between NL and SL with observed Warren et al.'s I = 0.0073 and Schoener's D = 0.0021. Species distribution modeling also separated their potential distribution. Morphometric analyses suggested significant interlineage differentiation of multiple traits including the ratio of length and width, leaf width, and pedicel length, although overall similarity did not differ. Based on the integrative species concept, two distinct species were proposed with legitimate names of Stewartia gemmata for SL and S. sinensis for NL. Our empirical study of the S. sinensis complex highlights the importance of applying multiple species criteria, in particular the underappreciated niche differentiation, to species delimitation in species complexes pervasive in plants. [ABSTRACT FROM AUTHOR]

The genus Wisteria (Fabaceae) is disjunctly distributed in eastern Asian and eastern North American temperate deciduous forests, and it is widely cultivated around the world as spectacular garden plants. It is a member of inverted repeat‐lacking clade (IRLC). The IRLC Species are characterized by the loss of an IR region in their plastomes, which has long been of great interest. In this research, we report whole plastome sequences from all four Wisteria species and a Wisteriopsis japonica, combining these with existing data to explore phylogenetic relationships and biogeography of Wisteria, as well as plastome evolution of IRLC species. Phylogenetic analyses recognized a clade containing Glycyrrhiza–Wisteriopsis–Wisteria as sister to the remaining genera of IRLC. North American Wisteria frutescens and the three Asian species formed reciprocal clades, and Wisteria brachybotrys was sister to Wisteria floribunda and Wisteria sinensis. Wisteria may have originated in Japan near the boundary of the Oligocene and Miocene. The disappearance of Bering Land Bridge in the late Miocene might lead to the Eastern Asian–Eastern North American disjunction of Wisteria. Allopatric speciation of Wisteria between the Japanese archipelago and the Asian continent in the Quaternary increased the species richness of eastern Asia in comparison with eastern North America. Synonymous substitution rates (dS) of protein‐coding genes in the IRLC species were around 2‐fold (SC genes) or 11‐fold (IR genes) higher than those of non‐IRLC species. For both SC and IR genes, herbaceous legumes have around 3‐fold higher dS than woody ones. Both loss of one IR region and herbaceous habit elevated substitution rates of the plastomes. [ABSTRACT FROM AUTHOR]

Latitudinal diversity gradients (LDGs) of species richness in most marine taxa appear to be bimodal with a dip at the equator. We compared LDGs for modeled ranges of 5,619 marine fish species, and distinguished between: all, pelagic, demersal, bony and cartilaginous fish groups; five taxonomic levels of class, order, family, genus and species; and four depth zones namely whole water column, 0–200 m, 200–1,000 m, and 1,000–6,000 m; at 5° latitudinal intervals. The modality of 88 LDGs was examined visually and using Hartigan's dip statistic. We found 80 LDGs were bimodal (or not unimodal), two gradients were unimodal and six gradients were ambiguous. All species and genera, and 19 families among fish groups and depth zones had bimodal or not unimodal LDGs. The northern hemisphere mode had 2–6% greater richness from species to order richness. Overall fish, the peak of richness shifted poleward across taxonomic levels, from 25°N for species to median 48°N for class and from 10°S for genus to 35°S for class. Temperature and salinity were significantly correlated with the LDG. Our findings using fish species ranges support previous analyses using species' occurrences, namely that the LDG of marine species is bimodal, by generalizing this to all taxonomic levels and depth zones. That the LDG with a dip near the equator supports the hypothesis that it is primarily temperature driven, and that the equator is already too hot for some species. [ABSTRACT FROM AUTHOR]

Species identification based on the DNA sequence of a fragment of the cytochrome c oxidase subunit I gene in the mitochondrial genome, DNA barcoding, is widely applied to assist in sustainable exploitation of fish resources and the protection of fish biodiversity. The aim of this study was to establish a reliable barcoding reference database of the native ray-finned fishes in Taiwan. A total of 2993 individuals, belonging to 1245 species within 637 genera, 184 families and 29 orders of ray-finned fishes and representing approximately 40% of the recorded ray-finned fishes in Taiwan, were PCR amplified at the barcode region and bidirectionally sequenced. The mean length of the 2993 barcodes is 549 bp. Mean congeneric K2P distance (15.24%) is approximately 10-fold higher than the mean conspecific one (1.51%), but approximately 1.4-fold less than the mean genetic distance between families (20.80%). The Barcode Index Number ( BIN) discordance report shows that 2993 specimens represent 1275 BINs and, among them, 86 BINs are singletons, 570 BINs are taxonomically concordant, and the other 619 BINs are taxonomically discordant. Barcode gap analysis also revealed that more than 90% of the collected fishes in this study can be discriminated by DNA barcoding. Overall, the barcoding reference database established by this study reveals the need for taxonomic revisions and voucher specimen rechecks, in addition to assisting in the management of Taiwan's fish resources and diversity. [ABSTRACT FROM AUTHOR]

The complete mitochondrial genome of the tiger tail seahorse was sequenced using a polymerase chain reaction-based method. The total length of mitochondrial DNA is 16,525 bp and includes 13 protein-coding genes, 2 ribosomal RNA, 22 transfer RNA genes, and a control region. The mitochondrial gene arrangement of the tiger tail seahorse is also matching the one observed in the most vertebrate creatures. Base composition of the genome is A (32.8%), T (29.8%), C (23.0%), and G (14.4%) with an A+T-rich hallmark as that of other vertebrate mitochondrial genomes. [ABSTRACT FROM AUTHOR]

The complete mitochondrial genome of the Wanieso lizardfish (Saurida wanieso) was determined by using a PCR-based method. The total length of mitochondrial DNA is 16,552 base pairs including 13 protein-coding genes, 2 ribosomal RNA, 22 transfer RNA genes, 1 replication origin region and 1 control region as otherSauridaspp. and bony fish. Base composition of the genome is A (25.7%), T (25.2%), C (31.5%), and G (17.6%) with an A + T-rich hallmark as that of other vertebrate mitochondrial genomes. [ABSTRACT FROM PUBLISHER]

The underlying causes of biodiversity disparities among geographic regions have long been a fundamental theme in ecology and evolution. However, the patterns of phylogenetic diversity (PD) and phylogenetic beta diversity (PBD) of congeners that are disjunctly distributed between eastern Asia-eastern North America (EA-ENA disjuncts) and their associated factors remain unknown. Here we investigated the standardized effect size of PD (SES-PD), PBD, and potentially associated factors in 11 natural mixed forest sites (five in EA and six in ENA) where abundant EA-ENA disjuncts occur. We found that the disjuncts in ENA possessed higher SES-PD than those in EA at the continental scale (1.96 vs  -1.12), even though the number of disjunct species in ENA is much lower than in EA (128 vs 263). SES-PD of the EA-ENA disjuncts tended to decrease with increasing latitude in 11 sites. The latitudinal diversity gradient of SES-PD was stronger in EA sites than in ENA sites. Based on the unweighted unique fraction metric (UniFrac) distance and the phylogenetic community dissimilarity, PBD showed that the two northern sites in EA were more similar to the six-site ENA group than to the remaining southern EA sites. Based on the standardized effect size of mean pairwise distances (SES-MPD), nine of eleven studied sites showed a neutral community structure (-1.96 ≤ SES-MPD ≤ 1.96). Both Pearson's r and structural equation modeling suggested that SES-PD of the EA-ENA disjuncts was mostly associated with mean divergence time. Moreover, SES-PD of the EA-ENA disjuncts was positively correlated with temperature-related climatic factors, although negatively correlated with mean diversification rate and community structure. By applying approaches from phylogenetics and community ecology, our work sheds light on historical patterns of the EA-ENA disjunction and paves the way for further research., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 Kunming Institute of Botany, Chinese Academy of Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co., Ltd.)