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The effect of substrate grain size on burrowing ability and distribution characteristics of Perinereis aibuhitensis
Sun Tao, Liu Chun'e, Li Xingzuo, An Dongzhengyang, Yu Hairui, Ma Zheng, Liu Feng
2019, 38(12): 52-58. doi: 10.1007/s13131-019-1348-z
Keywords: Perinereis aibuhitensis, substrate, grain size, burrowing ability, distribution characteristics
Perinereis aibuhitensis (Grube, 1878) lives in marine sediments of estuary or shoal areas, where substrate has some crucial environmental factors affecting its burrowing and distribution. In order to provide basic data for the habitat selection and suitability evaluations of the artificial aquaculture of P. aibuhitensis, this paper conducted a quantified analysis of its burrowing ability and explored its behavioral preferences in different substrates, including mud ( < 75 μm), fine sand (125-250 μm), medium sand (250-500 μm), coarse sand (500-2 000 μm), gravel (2 000-4 000 μm) and ceramsite (4 000-8 000 μm). The research results revealed that substrate grain size significantly affected the burrowing time, burrowing rate, burrowing depth and distribution rate (P < 0.01). Moreover, P. aibuhitensis demonstrated preferential selections relating to substrate grain sizes, had higher burrowing ability in ceramsite, mud and fine sand compared with other substrates. The strongest burrowing ability and the highest distribution rate were observed in ceramsite. The study indicated that P. aibuhitensis was sensitive to substrate grain size, which also had an impact on its burrowing process and population distribution. In the natural sea, substrates mainly composed of mud and fine sand are fit for aquaculture and stock enhancement. Based on behavioral preferences and ecological rehabilitation function of P. aibuhitensis, this paper proposes a symbiotic system of marine animals and halophytes, and constructs an ecosystem model of “Marine fish-Halophytes-Perinereis aibuhitensis” with P. aibuhitensis as the link.
Microbiota of a seepage face at the mouth of a subterranean estuary: diversity, distribution and substrate dependence
Yueming Wu, Yongjun Wei, Juan Severino Pino Ibánhez, Danqing Sun, Kaiqi Lu, Qianqian Wang, Jian Li, Shan Jiang
2023, 42(8): 147-157. doi: 10.1007/s13131-023-2257-8  Published:2023-08-31
Keywords: subterranean estuary, microbiota, seepage face, seasonal variation, substrate
Subterranean estuaries, i.e., the mixing zone between terrestrial groundwater and recirculated seawater, host a wide range of microbiota. Here, field campaigns were conducted at the mouth of the subterranean estuary at the Sanggou Bay (Shandong Province, China) over four consecutive seasons at a seepage face (0−20 cm depth). The diversity of benthic microbiome was characterized via 16S rRNA gene sequencing and metagenomics, combined with physic-chemical parameters, e.g., organic carbon, total nitrogen and sulfate contents in sediments. During spring, the dominant species were assigned to the phylum Proteobacteria. Important opportunistic species was assigned to Acidobacteria, Actinobacteria and Bacteroidetes. The key components were identified to be species of the genera Pseudoalteromonas, Colwellia and Sphingobium, indicating the involvement of sediment microbiota in the degradation of sedimentary organic carbon, particularly that of pelagic origin, e.g., phytoplankton detritus and bivalve pseudo-feces. During spring, the microbial community was statistically similar along the depth profiles and among the three sampled stations. Similar spatial distributions were obtained in the remaining seasons. By contrast, the dominant species assemblages varied significantly among seasons, with key genera being Thioprofundum and Nitrosopumilus during summer and autumn and Thioprofundum and Ilumatobacter during winter. Network analysis revealed a seasonal shift in benthic nitrogen and sulfur metabolism associated with these variations in microbial community composition. Overall, our findings suggested that macro elements derived from pelagic inputs, particularly detrital phytoplankton, shaped the microbial community compositions at the seepage face, resulting in significant seasonal variations, while the influence of terrestrial materials transported by groundwater on the sediment microbiota at the seepage face found to be minor.
A STUDY OF ALGINATE LYASES Ⅱ. THEIR EFFECTS ON SUBSTRATE
ZHU RENHUA, SHI HUIXIONG, LIU RUGAO
1987(3): 434-443.
Two acid partial hydrolysis methods are used in preparing three substrates, i. e. short-chain poly-mannuronide (SM), short-chain polyguluronide (SG) and short-chain polymannuronide-polyguluronide (SMG).
Using viscosity reduction method, it is demonstrated that lyase Ⅰ is an exolyase while lyase Ⅱ and lyase Ⅲ are endolyases.
Somogyi-Nelson method is used for determining the reducibility of lyase-decomposed substrates, indicating that the three lyases acted strongly on algin, SM and SMG, but slightly on SO. UV absorption method is used for determining absorption spectrum of products, indicating that all the three lyases are polymannuronide lyases (EC 4·2·99·4).
With their aigins decomposed, all the three lyases can reduce the M/G value, the best being lyase I which can reduce the M/G by about 3.65 fola. Therefore, the enzymatic method might be used in preparing medicine for preventive absorption of 90Sr.
Purification and characterization of lipoxygenase from Entermorpha clathrata
YANG Wenge, XUE Changhu, XU Dalun, FU Xueyan, HE Xiong
2008(1): 92-101.
Keywords: Entermorpha clathrata, lipoxygenase, purification, characterization
The purification and characterization of lipoxygenase (LOX, EC 1.13.11.12) from the green algae Enteromorpha clathrata were studied. Two components marked LOX-1 and LOX-2 were purified and their molecular masses were estimated to be 102 and 79 ku by SDS-PAGE. Both LOX-1 and LOX-2 were stable over the pH wide range 6.0~10.0 and had the optimum pH of 10.0 and 8.6, at optimum temperature of 30 and 25℃, respectively. Substrate specificities of LOX-1 and LOX-2 were the greatest towards linoleic acid, followed by arachidonic acid and linolenic acid. The Michaelis constant values of LOX-1 and LOX-2 were 0.23 and 0.20 mmol/dm3 with the substrate of linoleic acid. The LOX activities were stimulated greatly by Ca2+ but inhibited by Hg2+ and the antioxidants such as BHA, BHT and TBHQ. The hydroperoxide products of LOX were analysed by HPLC with the substrate of methyl linoleate, and the results showed that LOX-1 formed mainly 9-hydroperoxides while LOX-2 formed both 9-and 13-hydroperoxides at a ratio of 24:76.
Growth of marine bacteria and ammonium regeneration from substrates in different C: N ratios
WANG Jiangtao, YIN Xiaonan
2009(3): 59-64.
Keywords: marine bacteria, C:N, bacteria growth efficiency, ammonium
Natural assemblages of marine bacteria were chosen in a batch culture experiments. The impact of varying nitrogen substrate concentrations and the substrate C:N ratios (C:NS) on the bacterial C:N ratio (C:NB), the bacterial growth efficiency (BGE) and ammonium regeneration was mainly examined. The C:NS ratios varied from 5:1 (carbon limitation) to 40:1 (nitrogen limitation) with varying combinations of glucose and NO3-. The C:NB ratio had positive relationship with the C:NS ratio (r=0.93, n=8), whose value was 3.77 when the C:NS ratio was 5:1 but increased to 6.47 when the C:NS ratio was 40:1. These results indicate that the C:NB ratio is a potential diagnostic tool for determining the bacterial growth in natural waters controlled by either, carbon or nitrogen. BGE decreased with the declining nitrate concentration and negatively related to C:Ns (r=-0.51, n=8). The average value of BGE was 0.20. This value was a little lower than other reports, which could be induced by the nitrogen source used in our experiments. Finally, regeneration time of ammonium delayed with the increasing C:NS ratio, which indicates that there were different metabolism mechanisms when bacterial growth was limited by carbon source and nitrogen source.
First record of Odontaster penicillatus populations (Philippi, 1870) (Echinodermata: Asteroidea) in the Atacama and Antofagasta regions, Chile (Southeast Pacific)
Leonardo Campos, Fernando Berrios, Brenda B. Hermosillo-Núñez, Marco Ortiz
2022, 41(12): 152-155. doi: 10.1007/s13131-021-1957-1  Published:2022-12-30
Keywords: Odontaster penicillatus, new record, Antofagasta, Atacama, South Pacific Ocean
We report for the first time the presence of local populations of the starfish Odontaster penicillatus in the regions of Atacama and Antofagasta, Chile. This finding indicates an extension of the distribution limit of 500 km with respect to the last observation made in 2007 in Isla Grande de Atacama. A total of 121 specimens of O. penicillatus were recorded at depths of between 8 m and 24 m. They were associated with rocky substrate and with different species of barnacles, sponges and bryozoans. The presence of O. penicillatus expands the knowledge of the benthic biodiversity of the region, and the development of studies on its ecological importance will be promoted.
Notes Effects of four nitrogen substrates on growth of several red tide species
Yan Tian, Zhou Mingjiang, Qian Peiyuan
2002(3): 461-467.
Keywords: Red tide, nutrient, N-substrate
Eight common red tide species including the Dinoflagellates Ale randrium tamarense,Prorocentrum minimum, Prorocentrum mican, Diatoms Skeletonema costatum, Cerataulina pelagica, Leptocylindrus minimus, a Raphidophyte Heterosigma akashiwo and a Chrysophyte Ivohrysis galbana were chosen to study the effect of four nitrogen substrates (NO3-N, NH4-N, Urea-N,Mixed-N) on the growth of these algae. After two transfers, the results showed that at N concentration of 550μmol, NO3-N was the best nitrogen source among these four nitrogen substrates; Urea-N and Mixed-N were also good for the growth of most algae, but not as good as NO3-N for some species; NH4-N inhibited the growth of all these species except H. akashiwo. At concentrations of 280 and 50 μmnol experiments on the growth of I. galbana, P. minimum and L. minimus in NH4-N and NO3-N substrates were also performed. The results showed that the growth rates of I. galbana were not significantly different from each other in NO3-N and NH4-N substrates both concentrations of 280 and 50 μmol. In concentration of 280μmol NH4-N substrate, the growth rates of P. minimum and L. minimus were slower than in same concentration of NO3-N; At concentration of 50μmol, the growth rate of P. minimum in NH4-N was not significantly different from that in NO3-N, while the growth rate of L. minimus was only about 30% of that in NO3-N substrate.The results indicated that each alga had its own preference in N-substrate and concentration, therefore,different nitrogen substrates may play a role in red tide formation.
STUDY OF MARINE MICROFOULING ORGANISMSSOME CHARACTERISTICS OF THE MICROFOULING TO FIVEMATERIAL SURFACES OBSERVED BY THE SCANINGELECTRON MICROSCOPE
LIN YANSHUN, LIANG ZIYUAN
1984(3): 437-440.
In the last few years, scanning electron microscope (SEM) has been widely used to observeand study community structure and succession of the microfouling organisms on various solid surfaces immersed in the sea[1-3], polysaccharide components of bacterial slime layer[4-6], two-tier microfouling layer structure[6, 7], metal corrosion products in the attached process and character-istics of attached microorganisms on the coating surfaces[8, 9].The SEM observations indicated that substrate components exposed to natural seawater are one of the important factors affecting microbial adhesion[7, 10].The present paper examined the influences of several metal materials, from which ship is usually made on microbial adhesion during the exposure to seawater by the SEM and discussed the material selecting problems from the anti-microfouling point of view.
Variability in the empirical leucine-to-carbon conversion factors along an environmental gradient
LI Xiangfu, XU Jie, SHI Zhen, LI Qian, LI Ruihuan
2018, 37(4): 77-82. doi: 10.1007/s13131-018-1144-1
Keywords: bacteria, leucine incorporation, conversion factors, Zhujiang (Pearl River) Estuary
Bacterial production is one of the key parameters to evaluate bacterial role in ocean carbon fluxes. Estimation of bacterial production requires the leucine-to-carbon conversion factors that change widely across environments. However, empirical leucine-to-carbon conversion factors (eCFs) are seldom determined in situ because of time consuming and little is known on regulating factors for the eCFs. During May 2015 to January 2016, fourteen dilution experiments were conducted, from the Zhujiang (Pearl River) Estuary to the coast of the northern South China Sea, to determine spatiotemporal variability in the eCFs and its potential controlling factors along an environmental gradient. The eCFs showed clear spatial variations with the highest (1.27-1.69 (kg C)/(mol Leu)) in low salinity waters (salinity<15), intermediate (1.03-1.25 (kg C)/(mol Leu)) in moderate salinity (salinity of 15-25), and the lowest (0.48-0.85 (kg C)/(mol Leu)) in high salinity waters (salinity>25). Substrate availability was responsible for spatial variability in the eCFs. In the pristine coastal waters, low eCFs was related to substrate limitation and leucine incorporated was respired to maximize the survival rather than bacterial production. Hence, the eCFs measurement was needed for estimating bacterial production accurately in various marine environments.
The first snapshot study on horizontal distribution and identification of five peritrich ciliates (Genus Vorticella Linnaeus and Zoothamnium Bory de St. Vincent) from the eastern Indian Ocean
MUNIR Sonia, SUN Jun
2018, 37(10): 79-85. doi: 10.1007/s13131-018-1303-4
Keywords: Vorticella oceanica, Zoothamnium alternans, Zoothamnium alrasheidi, Zoothamnium marinum, Zoothamnium pelagicum, eastern Indian Ocean
Epipont peritrich ciliates are one of the most sessilie protists that attached to the substrate of zooplankton communities especially copepods and crustaceans. Peritrich ciliates can be solitary or colonial form found from the coastal zones and embayment around the world. Present research report is the first snapshot study of the peritrich ciliates and the horizontal distribution in open waters from surface to 200 m depth in the eastern Indian Ocean. Recently, five peritrich ciliates, e.g., Vorticella oceanica, Zoothamnium alternans, Z. alrasheidi, Z. pelagicum, and Z. marinum were collected from plankton net tow samples during the cruise from April 10 to May 13, 2014. The characteristics of the peritrich ciliate were determined according to the shape of the zooids, the ciliary structure and the stalks. The morphometric shape, sizes and characters also explained by examination under light/scanning electron microscopy. Vorticella oceanica and Z. pelagicum showed their association with host such as diatom (i.e, Chaetoceros coarctatus) and copepod (Oithona brevicornis) including some individuals around the dinoflagellate species (Ceraitum tripose). The distribution of these sessilid ciliates was dominated by the V. oceanica, Z. pelagicum and Z. marinum at the southeast zone while the large colonies of Z. alrasheidi observed at the Bay of Bengal. This distribution can be influenced by substrate availability like diatom (Ch. coarctatus) and copepods (O. brevicornis).
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