Trophic niche and potential carbon source of three reef-associated fishes of Zhongjieshan Islands.

To clarify the trophic relationship of important rock fishes, we analyzed trophic niche of three typical rockfish species (Oplegnathus fasciatus, Sebastiscus marmoratus and Conger myriaster) in the Zhongjieshan Islands in summer 2020, based on the carbon and nitrogen stable isotope techniques. We calculated the contributions of major carbon sources [macroalgae, phytoplankton, suspended particulate organic matter (POM) and substrate organic matter (SOM)]. The results showed that: 1) the δ13C values of the three species ranged from -21.44‰ to -15.21‰, with an average value of (-16.85±1.12)‰, while the δ15N values ranged from 8.32‰ to 10.96‰, with an average value of (9.69±0.66)‰. There were significant differences in carbon and nitrogen stable isotopes among the three species. 2) There was small niche overlap between O. fasciatus and S. marmoratus, indicating that the interspecific competition was not intense. There was no overlap between C. myriaster and the first two, indicating feeding differentiation. 3) The total ecotone area, corrected core ecotone area, and food source diversity of C. myriaster were the highest, indicating that it had a more generalized diet and richer food sources. 4) With Mytilus coruscus as a baseline organism, the trophic level of C. myriaster was the highest (3.38), followed by S. marmoratus (3.09), and the trophic level of O. fasciatus was the smallest (3.00). 5) Results of the stable isotope mixture model (SIAR) showed that POM was the main carbon source of the three species, contributing 57.4%, 57.9%, and 92.0% of the total, respectively. In addition, the contribution rate of SOM was also high for O. fasciatus and S. marmoratus, which was 21.5% and 33.9%, respectively. This study could provide basic information and reference for understanding trophic structure and marine food web in Zhongjiashan Islands.

The complete chloroplast genome sequence of Spiraea×vanhouttei (Briot) Zabel (Rosaceae).

Spiraea×vanhouttei (Rosaceae) is a frequently planted Spiraea species that is distributed in Shandong Province, Jiangsu Province, and Guangdong Province, China. The first complete chloroplast genome of Spiraea×vanhouttei was determined and described in this study. The genome is 155,957 bp in length and contained 129 encoded genes in total, including 84 protein-coding genes, eight ribosomal RNA genes, and 37 transfer RNA genes. The phylogenomic analysis showed that Spiraea×vanhouttei was closely related to Spiraea blumei according to the current sampling extent.

CuInS2/ZnS QD exposure induces developmental toxicity, oxidative stress and DNA damage in rare minnow (Gobiocypris rarus) embryos and larvae.

Chinese rare minnow (Gobiocypris rarus) embryos were used as an experimental model to investigate the effects of CuInS2/ZnS quantum dots (QDs) on the early life stages of G. rarus. Normal developmental parameters (survival rate, body length and average heart rate), biomarker genes [stress response (Hsp70), detoxification (Cyp1a), organizer function and axis formation (Wnt8α), and muscle (Mstn)], enzymatic activity and DNA damage were recorded as endpoints in the developing embryos/larvae after exposure until 96h post-fertilization (hpf). Reduced survival rate, decreased heart rate, altered body length, increased malformation rate, decreased hatching rate, advanced hatching time in response to low concentrations (50 and 100nmol/L) and delayed hatching time in response to high concentrations were observed after exposure, as were many other toxic effects, including pericardial edema and bent tails. The 72 hpf LC50 (median lethal concentration) was determined to be 624.364nmol/L. Treatment with certain concentrations of CuInS2/ZnS QDs significantly increased the superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels and significantly induced DNA damage. After treatment with CuInS2/ZnS QDs, the embryos showed highly up-regulated expression of Hsp70, Cyp1a and Wnt8a and significantly up-regulated expression of Mstn at 12 hpf. Overall, this study indicates that CuInS2/ZnS QDs are potentially toxic to G. rarus embryos. The information presented in this study will be helpful for fully understanding the toxicity induced by CuInS2/ZnS QDs in fish embryos.

Developmental Toxicity of Carbon Quantum Dots to the Embryos/Larvae of Rare Minnow (Gobiocypris rarus).

The toxic effects of CDs on rare minnow (Gobiocypris rarus) embryos at different developmental stages were investigated. The results showed that rare minnow embryos had decreased spontaneous movements, body length, increased heart rate, pericardial edema, yolk sac edema, tail/spinal curvature, various morphological malformations, and decreased hatching rate. Biochemical analysis showed the CDs exposure significantly inhibited the activity of Na+/K+-ATPase and Ca2+-ATPase and increased the MDA contents and the activity of SOD, CAT, and GPX. Further examination suggested that the CDs exposure induced serious embryonic cellular DNA damage. Moreover, the CDs exposure induced upregulation of development related genes (Wnt8a and Mstn) along with the downregulation of Vezf1. Overall, the present study revealed that the CDs exposure has significant development toxicity on rare minnow embryos/larvae. Mechanistically, this toxicity might result from the pressure of induced oxidative stress coordinate with the dysregulated development related gene expression mediated by the CDs exposure.

Angiogenesis inhibition in vascular endothelial cells by terpenoid compounds from Bletilla striata is via apoptosis pathway.

The inhibitive effects on angiogenesis and the potential mechanism by terpenoids from Bletilla striata were investigated in the study. Terpenoids were separated and purified from Bletilla striata by extraction and chromatography. The terpenoid and its crude extracts were used to treat on blood vessel of chick chorioallantoic membrane (CAM), as well as human umbilical vein endothelial cell (HUVEC). Our results demonstrated that the crude extracts containing the terpenoids could inhibit CAM angiogenesis and pure terpenoid sample could prohibit HUVEC proliferation and induce HUVEC undergoing apoptosis, which showed an apparent apoptotic characterizations, such as cell shrinking, blebbing of cell membrane, nucleus cracking, chromatin condensation and margination, apoptotic body formation and DNA degradation. Therefore, the inhibition on angiogenesis by terpenoids from Bletilla striata is depended on the induction of apoptosis to endothelial cells.