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Two new diatom species belonging to the genus Gomphonemopsis are described, Gomphonemopsis nana sp. nov. and Gomphonemopsis gaoi sp. nov. These two species were compared in detail with congeners. Gomphonemopsis nana is distinguished by its high stria density and small size. This species was found so far to be epiphytic only on the eelgrass collected from Qingdao Bay (Yellow Sea). Gomphonemopsis gaoi is characterized by its isopolar valves, simple proximal raphe endings and acutely rounded apices. This taxon was separated from the exoskeleton of marine copepods sampled from the Futian Mangrove Nature Reserve (South China Sea). In addition, two new combinations, Gomphonemopsis oahuensis (Hustedt) Lang Li, Yuhang Li & Changping Chen, comb. nov. and Gomphonemopsis platypus (Østrup) Lang Li, Yuhang Li & Junxiang Lai, comb. nov. are proposed. This study increases the records and knowledge of Gomphonemopsis along the coast of China. [ABSTRACT FROM AUTHOR]

Length-weight relationships (LWRs) were reported for ten fish species (Abbottina rivularis, Hemibarbus labeo, Hemibarbus maculatus, Onychostoma macrolepis, Opsariichthys bidens, Rhynchocypris lagowskii, Schizothorax prenanti, Sinibrama macrops, Zacco platypus, and Siniperca scherzeri). Fishes were collected from 62 sampling stations covering an area of ∼7000 km2 in the Qinling Mountains, characterized by unique fauna and distribution pattern, using gillnets and ground cages during June to December 2022. The intercept a ranged from 0.013 for S. prenanti to 0.060 for H. labeo, and the slope b ranged from 2.537 for H. labeo to 3.079 for Z. platypus. [ABSTRACT FROM AUTHOR]

Zacco tiaoxiensis, a new species of cyprinid fish from Tiaoxi river system in Zhejiang Province, southern China, is described. With morphological comparison, the new species is similar to Z. acanthogenys, which is widely distributed in Zhejiang Province. However, the new species could be distinguished from Z. acanthogenys by the following combination of characters: lateral- line scales comprising 41-44 (vs. 44-47), scales above lateral-line 8 (vs. 8-10), scales below lateral-line 3-4 (vs. 4-5), scales surrounding caudal peduncle 12-15 (vs. 14-17), for mature male individuals, the ventral fin reaching (vs. exceeding) the anus, etc. The morphological differences among the new species and the allopatric congener species of Z. sinensis and Z. platypus are mainly in the number of scales under the lateral line, comparable characters such as the ratio of head length to body length, and the color of the upper edge of the eyes when living. Moreover, the genetic analysis based on mitochondrial cytochrome b gene also supports that Zacco tiaoxiensis sp. nov. is a valid species. [ABSTRACT FROM AUTHOR]

The spatial–temporal patterns of fish assemblages in lotic systems can provide useful information in developing effective conservation measures. This study aimed to explore the spatial and seasonal changes in fish assemblages and their association with environmental factors in mountain streams of the Ren River, southwest China. Field investigations were conducted at 18 sites during the rainy and dry seasons in 2017. A total of 1,330 individuals, belonging to three orders, eight families, 19 genera, and 21 species, were collected. Analysis of similarities (ANOSIM) showed that the structure of fish assemblages varied significantly at the spatial scale, but not at the seasonal scale. In low‐order sites, fish assemblages were mainly dominated by cold‐water and rheophilic species (e.g., Rhynchocypris oxycephalus, Scaphesthes macrolepis, Metahomaloptera omeiensis, and Gnathopogon herzensteini), while those in high‐order sites were predominated by warm‐water and eurytopic or stagnophilic species (e.g., Squalidus argentatus, Hemiculter leucisculus, and Zacco platypus). Canonical correspondence analysis (CCA) showed that the fish assemblages were structured by a combination of large‐scale landscape factors (e.g., altitude and C‐link) and small‐scale habitat features (e.g., channel width, water temperature, and depth). Among these factors, landscape had the greatest influence on fish assemblages, while local habitat variables were less important or were only significant in certain seasons. [ABSTRACT FROM AUTHOR]

We compared the phylogenetic relationships and the population structure of the sympatric cyprinids Opsariichthys bidens and Zacco platypus across the Yangzte, Pearl and Hai He drainages in Mainland China. We used the mitochondrial cytochrome b gene to evaluate their phylogeographical structure and to discuss further systematic implications. We sequenced 71 new individuals of Z. platypus to add to a previous study and to construct a geographically comparable data set with O. bidens (Mol. Phylogenet. Evol. 31, 2004, 192; Mol. Phylogenet. Evol. 37, 2005, 920). Phylogeographic analysis of Z. platypus identified two additional mtDNA lineages (Zacco E and F) in addition to the previously recovered lineages (Zacco A–D). The geographical range of the Zacco A was extended across the Pearl drainage, broadening considerably the previous distribution that was circumscribed to the Yangtze drainage. Our results show high molecular divergence between all Zacco A–F mtDNA lineages (mean TrN + I + G distance 17.7%, range 4.4-30.8%), and the population analyses showed that most of the genetic variation was found among major river tributaries (90.2%). Values of θST higher than 0.97 corroborated this interruption of gene flow between Zacco A–F mtDNA lineages. Nested clade analysis results were also concordant with the phylogenetic relationships recovered. We found similar phylogeographic patterns in Z. platypus and O. bidens: they exhibited two widespread and common lineages (Zacco A and Opsariichthys 1) ranging across the Yangtze and Pearl drainages, and both taxa had Northern lineages (Zacco F and Opsariichthys 5) clearly differentiated. Similar phylogeographic patterns suggest that common historical factors have shaped current Zacco and Opsariichthys diversity. High genetic distances and θST values suggested that differentiation of Zacco A–F mtDNA lineages and Opsariichthys 1-5 was not recent and was probably favoured by old geological events. However, population parameters and low genetic differentiation inside Zacco A and Opsariichthys 1 suggest a recent gene flow across river drainages. Mitochondrial-based phylogenies for the combined data sets of Zacco A–F and Opsariichthys 1-5 mtDNA lineages always recovered both taxa as paraphyletic, highlighting the notion that their current systematics need a revision. [ABSTRACT FROM AUTHOR]

Platypus contaminatus attacked healthy hawthorn trees in China. The complete mitogenome of P. contaminatus was 15,712 bp in length. It contained 2 ribosomal RNA genes, 22 transfer RNA genes, 13 protein-coding genes and a 1038-bp long non-coding AT-rich region. This species showed rearrangements in mitochondrial genome. These changes included: (1) the reversal of the order of tRNATrp and tRNAGln genes; (2) tRNASer moved from its ancestral position (between cob and nad1) to the nad2–tRNAGln gene junction. Phylogenetic analysis using nucleotide sequences of 13 PCGs showed that P. contaminatus was closely related to Euplatypus parallelus, which was similar to the previous research. [ABSTRACT FROM AUTHOR]