Species delimitation and life stage association of Propsilocerus Kieffer, 1923 (Diptera, Chironomidae) using DNA barcodes.

The utility of COI DNA barcodes in species delimitation is explored as well as life stage associations of five closely related Propsilocerus species: Propsilocerus akamusi (Tokunaga, 1938), Propsilocerus paradoxus (Lundström, 1915), Propsilocerus saetheri Wang, Liu et Paasivirta, 2007, Propsilocerus sinicus Sæther et Wang, 1996, and Propsilocerus taihuensis (Wen, Zhou et Rong, 1994). Results revealed distinctly larger interspecific than intraspecific divergences and indicated a clear "barcode gap". In total, 42 COI barcode sequences including 16 newly generated DNA barcodes were applied to seven Barcode Index Numbers (BINs). A neighbor-joining (NJ) tree comprises five well-separated clusters representing five morphospecies. Comments on how to distinguish the larvae of P. akamusi and P. taihuensis are provided.

Polypedilum (Cerobregma) heberti sp. n. (Diptera: Chironomidae) from Gaoligong Mountains, Yunnan, China.

DNA barcodes and morphology recognize a new non-biting midge within the genus Polypedilum (Diptera: Chironomidae). Polypedilum (Cerobregma) heberti Lin et Wang sp. n. is described and illustrated based on an adult male from Gaoligong Mountains, Yunnan, China. Key to adult males of the subgenus Cerobregma is given.

[Utilization and growth response of Chrysosporum ovalisporum to different phosphorus compounds]. / 卵孢金孢藻对不同磷化合物的利用及生长响应.

To explore the ability of bloom-forming cyanobacterium Chrysosporum ovalisporum to utilize different kinds of phosphorus compounds in the water column, we examined the growth response of C. ovalisporum in the laboratory by taking dipotassium hydrogen phosphate as the control and set different treatments of phosphorus substrates. The results showed that C. ovalisporum could utilize sodium tripolyphosphate and terasodium pyrophosphate decahydrate, with better utilization of sodium tripolyphosphate. After 15 days, it had the highest biomass and chlorophyll a concentrations under the treatment of sodium tripolyphosphate, with a value of (426.96±47.42) mg·L-1 and (1852.34±116.60) µg·L-1, respectively. Compared with the control, there was no significant difference in biomass of C. ovalisporum under both the (2-aminoethyl)-phosphonic acid and disodium ß-glycerol phosphate pentahydrate treatments. The change characteristics of dissolved inorganic phosphate were related to the alkaline phosphatase activity, indicating that C. ovalisporum was able to utilize these two organophosphorus compounds via enzyme hydrolysis. The concentration of dissolved inorganic phosphate reached 0 mg·L-1 during the whole experiment when the C. ovalisporum were fed with glyphosate. Biomass, specific growth rate, chlorophyll a concentration and photosynthetic activity of algal cells were significantly lower than those of the control, indicating that C. ova-lisporum could not uptake phosphorus compounds in the glyphosate substrate and thus their growth being inhibited. Our results present new insights to understand the diffusion mechanism of C. ovalisporum into different aquatic ecosystems and had theoretical reference value for the prevention and control of new cyanobacterial blooms.

[Community structure of Chironomid larvae and their indicative significance for water quality in streams of Xianju National Park, China]. / ä»™å± å›½å®¶å ¬å›­æºªæµæ‘‡èšŠå¹¼è™«ç¾¤è½ç»“æž„åŠå ¶å¯¹æ°´è´¨çš„æŒ‡ç¤ºä½œç”¨.

In August 2016, 59 sites of 13 streams in Xianju National Park were surveyed to explore the community structure of Chironomid larvae and their indicative significance for water quality. Water quality of the streams was evaluated based on Hilsenhoff biological index. The results showed that there were 37 clean sites, 19 mild polluted sites and three moderated polluted sites in Xianju National Park. We identified a total of 86 species of Chironomid larvae, belonging to 51 genera and four subfamilies, including 37 species in 19 genera of Chironominae; 35 species in 21 genera of Orthcladiinae; 12 species in 9 genera of Tanypodinae, two species in two genera of Diamesinae. Chironominae accounted for 40.3% of Chironomid larval density. Tanypodinae and Orthcladiinae were almost similar in Chironomid larval density, respectively accounted for 30% and 29.4% of the total. Diamesinae accounted for 0.3% of total Chironomid larval density. Conchapelopia sp. was the overwhelming dominant species and Polypedilum flavum, Rheocricotopus sp., Cricotupus vierriensis, Rheotanytarsus muscicola and Corynoneura carriana were the dominant species of Chironomid larvae. The result of indicator species analysis showed that Cricotupus vierriensis, Nanocladius dichromus, Tanytarsus formosanus, Tanytarsus mendex were indicator species of moderated pollution water, and that Rheocricotopus sp. was the indicator species of clean state water.

[Community structure of macrozoobenthos and its relationship with environmental factors in Lake Gehu, Jiangsu, China.] / æ±Ÿè‹æ»†æ¹–å¤§åž‹åº•æ –åŠ¨ç‰©ç¾¤è½ç»“æž„åŠå ¶ä¸ŽçŽ¯å¢ƒå› å­çš„å ³ç³».

A survey on macrozoobenthos was conducted seasonally and 14 aquatic physicochemical parameters were monitored monthly to reveal the community characteristics of macrozoobenthos and their relationship with aquatic environmental factors at 20 sampling sites in the Lake Gehu from July 2013 to December 2014. A total of 25 macrozoobenthos species including 3 species (12% of total) of Mollusca, 12 species (48%) of Chironomidae, 4 species (16%) of Oligochaeta, 4 species (16%) of Crustacean were identified. The dominant species were Limnodrilus hoffmeisteri, Branchiuras owerbyi, Tanypus chinensis, and Propsilocerus taihuensis. Density and biomass of Chironomid larvae and Oligochata had significant spatial and seasonal changes. The state of aquatic environment was mainly affected by the nitrogen, phosphorus and water temperature in the Lake Gehu, and TN, NO3--N and DO changed significantly with space and season. The Spearman correlation analysis indicated that TN and NO3--N played a key role in the community structure characteristics of the macrozoobenthos in the Lake Gehu. The environmental variables could well explain the changes of main macrobenthic species.

[Physiological response of Neocaridina denticulate to the toxicity of Cu2+ and chlorpyrifos].

In order to study the physiological response to heavy metals and organic-phosphorus pesticide toxicity of aquatic organisms, Neocaridina denticulate was used as a test organism to investigate the impact of physiological indices of N. denticulate muscle tissues when they were exposed to Cu2+ and chlorpyrifos for 5 days respectively with the test methods of semi-static toxicity. The results showed that: when exposed to different concentrations of Cu2+ and chlorpyrifos solutions, the protein concentrations in muscle tissues were significantly lower with the extension of time to varying degrees. In the lower concentration groups of Cu2+ (0.086 mg x L(-1) and 0.172 mg-L-') and the higher concentration groups of chlorpyrifos (0. 006 0 [g-L-' and 0.012 0 µg x L(-1)), the total SOD activity showed inhibitory effect; the trend of the higher concentration group of Cu2+ (0.344 mg x L(-1) and 0.688 mg x L(-1)) showed " inhibition-promotion-inhibition", however, the lower concentration groups of chlorpyrifos (0.001 5 µg x L(-1) and 0.003 0 µg x L(-1)) showed the" inhibition-promotion" changes in trends; MDA contents changed similarly, and within a certain range of concentrations, MDA contents presented a gradually rising trend with increasing Cu2+ and chlorpyrifos concentration, which indicated that Cu2+ and chlorpyrifos accelerated lipid, peroxidation in muscle tissues of N. denticulate. In addition, AChE activity in Cu2+ and chlorpyrifos solutions showed inhibitory effect, and in the solutions with higher concentration of Cu2+ and chlorpyrifos, the activity was gradually decreased with the increase of concentration, indicating that Cu2+ and chlorpyrifoscs impacted the normal physiological functions of N. denticulate, and the higher the concentration, the greater the damage effect. Based on the analysis results, we confirmed that the total SOD, MDA and AChE played significant roles as physiological indicators in evaluating toxic effect of heavy metals and organic-phosphorus pesticide on N. denticulate.

[Succession of rotifer community and its relationship with environmental factors in a new Estuarial Landscape River, Shanghai].

The community structures of rotifers were surveyed in Lin'gang B Gang River, a new estuarial river in Shanghai, from December 2011 to November 2012. A total of 23 rotifer species were identified, of which 19 species were the indicator of environmental pollution. Rotifer species' number rose monthly from 2 to 13. A conspicuous succession of dominant species was observed from a single dominant species (Keratella cochlearis) to several species. The rotifer community structure of Lin'gang B Gang River differs with that of the outer water body (Lu Chaoyin River). Pearson analysis showed that the rotifers' density had a significant correlation with water temperature and chlorophyll-a (P <0. 05) , but had no significant correlation with salinity; the densities of dominant species (except Keratella cochlearis) presented negatively correlations with concentration of nutrients and salinity (P < 0. 05). The low species similarity index between every month demonstrated that aquatic ecosystem of Lin'gang B Gang River was in the unstable state. However, the increase of Margalef index and Shannon-Wiener index of rotifers and the decline of E/O value monthly showed the water environment of Lin'gang B Gang. River was improved.

[Phytoplankton community structure in Shijiuyang constructed wetland of Jiaxing, Zhejiang Province of east China in winter].

Aimed to explore the purification effect of constructed wetland on phytoplankton community structure, an investigation was conducted on the species composition, biomass, and community diversity of phytoplankton in the water body of Shijiuyang constructed drinking water source wetland of Jiaxing, Zhejiang Province of East China in winter, 2010. A total of 77 phytoplankton species were identified, belonging to 39 genera of 7 phyla. The main phylum was Bacillariophyta, with 33 species of 14 genera. The dominant species were Melosira varians, Cyclotella meneghiniana, Nitzschia sp., Chroococcus sp., Dactylococcopsis rhaphidioides, Scendesmus quadricauda, and Tribonema bombycium, among which, C. meneghiniana had the highest dominance (0.144). The phytoplankton density in winter was averagely 1.28 x 10(6) cell x L(-1), with the minimum (6.80 x 10(5) cell x L(-1)) in the water outlet, and the density of Cyanophyta in the water outlet was significantly lower than that in the water inlet (P < 0.05), only occupying 14.9% of the latter. The Shannon index of the phytoplankton community at the sampling sites ranged from 0.94 to 1.27. According to the cluster analysis and multidimensional scaling (MDS), the phytoplankton community was classified into five phytoplankton community groups, i.e., root-channels littoral community, root-channels flow community (2 styles), highly purified area community, and headwater region community. Diverse ecological environment and water flow velocity at the sampling sites were found to be the main contributors to the formation of the five phytoplankton community groups.

[Dynamic of phytoplankton abundance and the relationship with environmental factors in Dianshan Lake, Shanghai].

During January 2004 to December 2006, the abundance of phytoplankton and environmental factors such as the water temperature, wind speed, transparency of water (SD), TN, TP, pH, and permanganate index were monitored monthly in Dianshan Lake. The water quality of Dianshan Lake was in the mid-eutrophication state. The correlation analysis between phytoplankton community and environmental factors were performed. It indicated that the phytoplankton abundance, cyanobacteria abundance in Dianshan Lake were positively correlated with temperature (r = 0.487, r = 0.497), pH (r = 0.415, r = 0.379) and permanganate index (r = 0.460, r = 0.436), and negatively correlated with SD (r = -0.382, r = -0.394). Chlorophyta abundance in Dianshan Lake was positively correlated with PO4(3-) -P (r = 0.466). There was also a significant positive correlation between phytoplankton abundance and cyanobacteria abundance (r = 0.970). According to (CCA) ordination analysis, temperature, DO, SD and PO4(3-) -P were main factors affecting dynamic characteristics of phytoplankton community. The meteorological and hydrological factors were more important than nutrition concentration related to the water bloom in Dianshan Lake.