The studies about the niche and interspecific association in China were mainly focused on the plants, birds and marine animals, and seldom on fish. Based on the fishery resources survey in spring (May) and autumn (September) in 2015, the associations among major fish species in south coastal waters of Wenzhou were investigated. The methods including niche breadth, niche overlap, variance ratio (VR), Χ2-test, association coefficient (AC), percentage of co-occurrence (PC) and point correlation coefficients (Ф) were used. The results showed that 47 fish species were identified, including 9 orders, 27 families and 41 genera. Four species were dominant species and 9 were important species, which together accounted for 17%. The niche breadth cluster analysis demonstrated two clearly identifiable ecological niches. The first one referred to wide niche that included Harpodon nehereus, Collichthys lucidus, Engraulis japonicas, Pampus echinogaster, Argyrosomus argentatus, Polynemus sextarius, Decapterus maruadsi and Trichiurus haumela, and the second one was narrow niche that included Muraenesox cinereus, Amblychaeturichthys hexanema, Cunoglossus robustus, Pseudosciaena polyactis and Ilisha elongate. The niche overlap value of the main fish was 0-0.90, indicating that there was difference in the resource utilization among the species. The ecological niche widths of C. robustus and M. cinereus were narrow, and the overlap values were high. This indicated that there was competition between these two species. The VR analysis revealed significant positive correlation among the main fish species. In view of the advantages of Ф value, which could reduce the impact of the analysis results of Χ2-test, AC and PC to the interspecific association, the Ф value method was selected in this study, and the association of 63 couples were positive. Both the interspecific association and ecological niche had different degrees of correlation with the stability of community structure and community succession.

The southern coastal waters of Wenzhou is in the mid to southern parts of the East China Sea. This area is influenced by the high temperature and high salinity conditions of the Taiwan Warm Current, the low salinity of the Zhejiang Coastal Current, and the southern coastal upwelling. These waters are rich in nutrients and baitfish and are highly diverse with fish species. The area is a typical ecological region of the East China Sea shelf. Cluster analysis, non-metric multidimensional scaling, and a diversity index was used to analyze the patterns of commu-nity composition, diversity, and community structure based on data from two fishery resources investigations conducted in May (spring) and September (autumn) 2015 in the area. The results identified 47 species in the southern coastal waters of Wenzhou, which belonged to 41 genera, 27 families, nine orders, and two classes. Warmwater and warm temperate species were dominant, and Perciformes were the most abundant, with 26 species, followed by Clupeiformes, with six species. The third most frequent group was Tetraodontiformes, with four spe-cies. The dominant species in spring were Engraulis japonicas,Pampus echinogaster, Amblychaeturichthys hex-anema, and Collichthys lucidus, accounting for 49.3% of the total catch. The dominant species in autumn were Harpodon nehereus,Collichthys lucidus, and Polynemus sextarius, accounting for 50.8% of total catch.Engraulis japonicas, Decapterus maruadsi, Psenopsis anomala, Harpodon nehereus, Ilisha elongate, and Polynemus sex-tariuswere typically found at all stations in both seasons, and they were the major divergent species causing community differences among stations. Pearson's correlation analysis indicated that the richness index (D) and the Shannon–Wiener diversity index (H') were positively correlated with dissolved oxygen, salinity, and temperature. A canonical correspondence analysis suggested that the main environmental factors affecting the spatial patterns of fish assemblages were pH, depth, and salinity. pH represents the sum of some of the chemical properties in wa-ter and is the result of interactions among factors. pH can be affected by salinity and temperature. The canonical correspondence analysis results showed a division in the fish community in spring, which was likely due to influx of the high temperature and high salinity water in the Taiwan Warm Current. This current forms an obvious salin-ity gradient in the local coastal strip, which further affected the division of the spring fish community. The Taiwan Warm Current retreated in autumn, and the lower temperature and lower salinity of the Zhejiang and Fujian Coastal Currents gradually carried a large amount of silt into the study area. Therefore, whether temperature, sa-linity, and suspended particles affected the fish community structure requires further investigation.

According to the fishery resources survey data of Wenzhou Bay in Spring 2013 (May) and Spring 2014 (May),we used spatial niche breadth and overlap to determine the major niches of nekton.A series of methods,including the variance ratio (VR) method,x2 test,the association coefficient (AC),percentage of co-occurrence (PC),and functional group classification and trophic level constituents combined the means of niches were used to analyze the relationships among the major marine nekton species.The results showed that there were 18 major nekton species.The three dominant species were Amblychaeturichthys hexanema,Harpodon nehereus,and Pampus argenteus,which had large spatial niches.The other 15 species were main species.In general,there were large differences in the niche overlap values among the major nekton populations,with a maximum value of 0.88 and a minimum of 0.01,indicating a possible resource utilization competition among some nekton species.The VR value was greater than 1 at 9.90,and the W value was 366.39,which was considerably greater than the confidence interval (8.67,27.59).There were significantly positive correlations between the major nekton community species.The percentage co-occurrence of species showed that only three pairs had strong positive association,and no unrelated species pairs was revealed,have not unrelated species pairs.The coupling coefficient showed that 110 pairs of species tended to be independent,indicating that species were independent distributions.According to the type of feeding,the major nekton species could be divided into 5 functional groups:the planktophagous group (Pl),the phytophagous group (Ph),the carnivorous group (C),the omnivorous group (O),and the detritivorous group (D).In terms of percentages of the total nekton,these groups could be ordered as follows:C ＞ O =P1 ＞ D ＞ Ph.Based on the relationship among the functional groups,the trophic levels for major nekton species varied from the second to fourth trophic levels,the third and fourth trophic levels were the major trophic leves in our study.A complex food web is formed between each trophic level.

The macrobenthos is an important part of the ecological system in biological communities, and plays an im-portant role in energy transformation and material circulation. With the decline of marine fishery resources, the inter-tidal zones in six important islands of Zhejiang are seriously threatened by human activities, causing deep recession of some significant economic macrobenthos living resources. We investigated the taxonomic diversity of the macrobenthos of the intertidal zone, and protected the macrobenthos resources in several important islands of Zhejiang (East China Sea). We used the macrobenthos composition produced by the Checklist of Marine Biota of China Seas, which is based on the historical data of macrobenthos surveys in several important islands of Zhejiang since the 1980s. The species number, taxonomic diversity,G-F index and composition of species similarity index in the order and family levels were calculated. The results showed that species number in the macrobenthos differed in several important islands of Zheji-ang. The largest species number occurred in the Nanji Islands: a total of 330 macrobenthos species were recorded, be-longing to 213 genera, 124 families, 42 orders, 18 classes and 10 phyla. The lowest species number was recorded in the Taizhou Islands, with a total of 133 macrobenthos species belonging to 105 genera, 73 families, 29 orders, 15 classes and nine phyla. We used the PRIMER 5.2 software to calculate the average taxonomic distinctness index and the varia-tion in taxonomic distinctness index for several important islands of Zhejiang. The Shengsi islandshad the maximum average taxonomic distinctness index (84.76), while the minimum was the Taizhou Islands (70.89). Thus, the genetic relationship of the composition of the macrobenthos species in the Shengsi Islands was more distant than that of the other six islands. The maximum variation in taxonomic distinctness index was calculated for the Dongtou Islands (846.94) and the Shengsi Islands had the minimum (630.25). The islands showed the maximum G-Findex (0.87), which indicates a higherG-index on the premise of a constantF-index. Compared with the composition of macroben-thos species similarity index analysis at the order level,the composition of macrobenthos species similarity between the Dongtou Islands and Taizhou Islands was the highest (0.651) and the lowest was between the Yushan Islands and Shengsi Islands (0.480). At the family level,the highest composition of macrobenthos species similarity index was between the Dongtou Islands and Taizhou Islands (0.781) and the lowest was between the Taizhou islands and Yushan Islands. Thus, the macrobenthos species compositions were not significantly different between the Dongtou Islands and Taizhou Islands at the order and family levels. The macrobenthos of the intertidal zone taxonomic diversity in six im-portant islands of Zhejiang was analyzed, which provided references for conservation, development and management within the macrobenthos of the intertidal zoneof the Zhejiang Islands.

生物多样性的含义十分广泛, 不仅包括物种的多样性, 还包括物种间进化关系、进化历史以及生态系统等各层面的多样性[1].传统的生物多样性指数主要为Shannon- Wiener多样性指数、Pielous均匀度指数、Margalef物种丰富度指数等, 对研究生物多样性起到了促进作用, 但它们只是综合了一个群落内物种相对数量的信息量, 而未考虑物种间的差异以及它们的分类关系[2, 3].为了更好地研究生物多样性, Clarke等[4]提出了分类多样性指数,主要有分类多样性指数(Δ)、分类差异指数(?*)、平均分类差异指数(??)及分类差异变异指数(??).其中, 平均分类差异指数(??)和分类差异变异指数(??), 其理论平均值不取决于取样大小和取样方法, 对开展不同区域、不同生境间和历史数据的对比研究, 以及取样性质未知或不一致情况下的研究具有重要意义[3, 4].分类学多样性指数提出后在国内外得到了广泛的应用, 目前主要用于大型底栖动物[1]、浮游动物[5]以及鱼类[3, 6—13]等生物群落.

In this paper, the interaction between the species Population were analyzed based on the data of major nekton species in the south coastal waters of Cangnan in spring and autumn 2014. A series of methods including niche breadth, niche overlap, χ2 - test and association coefficient (AC) based on a 2x2 contingency table were used. The results showed that the major nekton species in the south coastal waters of Cangnan were classified into three groups, i.e. wide niche breadth species, moderate niche breadth species and narrow niche breadth species based on the niche breadth values. The wide niche breadth species of nekton were Harpodon nehereus, Portunus trituberculatus, mantis shrimp and other 2 species. The moderate niche breadth species of nekton were Collichthys lucidus, Parapenaeopsis hardwickii, Parapenaeopsis tenella and other 5 species. While the species with narrow niche breadths were Charybdis japonica, Amblychaeturichthys hexanema, Palaemon gravieri and other 7 species. There were great differences in the niche overlap values among the major nekton populations, with the maximum value of 0.93 and the minimum of 0, which indicated that resource utilization competition in some nekton might exist. The results of variance ratio analysis for major nekton in the south coastal waters of Cangnan showed that they were significantly positively correlated. χ2 - test results showed that there were significantly interspecific association for 78 species pairs (χ2≥3.841), among which more association coefficients (AC) of species pairs are positive.

Based on the bottom trawl surveys in May of 2013,we investigated the community structure and biodiversity of nekton near Oufei Beach of Wenzhou by traditional diversity analysis,abundance-biomass comparison curves,clustering analysis and non-metric multidimensional scaling. A total of 87 species were collected,including 55 species of fish,18 species of shrimps,10 species of crabs and 4 species of cephalopods. The dominant species were Amblychaeturichthys hexanema,Pampus argenteus and Harpodon ne-hereus;the important species were Lateolabrax maculatus,Collichthys lucidus and other 15 species. The densities of nekton quantity and weight were 304. 6 × 103 ind·km - 2 and 365. 8 kg·km - 2 ,respectively. Cluster analysis and non-metric multidimensional scaling (NMDS)analysis reveal that the nekton community could be spatially clustered into three groups. ANOSIM analysis shows very signifi-cant difference in nekton species composition among all groups(R = 0. 463 ~ 0. 807). The abundance and biomass curves(ABC)in-dicate that the nekton community was seriously disturbed,and the fast-growing,small-sized and opportunistic r-strategist was dominant in the nekton community. The Shannon-Wiener diversity index(H′),Pielou evenness index(J′)and Margalef species richness index (D)ranged from 1. 31 to 3. 74,0. 33 to 0. 78,and 1. 80 to 5. 81,respectively.

三疣梭子蟹(Portunus trituberculatus)隶属于甲壳纲、十足目、梭子蟹科、梭子蟹属,俗称梭子蟹、枪蟹、门蟹等,是一种重要的海洋经济蟹类,广泛分布在中国、日本、韩国及南亚各国近岸海域,是重要的渔业产品之一[1,2],由于其生长速度快、经济价值较高,我国沿海地区梭子蟹人工养殖十分广泛.目前,其养殖方式以围塘养殖为主,投饵量通常根据经验定量投喂,投饵方式基本采用抛撒式,因而在养殖过程中,往往会出现投饵不足或者过量的情况.饵料不足不仅影响梭子蟹生长,且会造成梭子蟹互相残杀;而饵料过量不仅会浪费成本,且会污染水体,影响水质,更可能致使梭子蟹疾病多发甚至死亡,养殖效益降低.

基于2012年5、8和10月对唐山湾海域进行底拖网渔业资源调查的资料,采用相对重要性指数、多样性指数及群落ABC曲线等分析方法,对3个季节渔业资源现状及群落多样性进行研究.结果显示:渔获物中共有海洋动物59种,其中鱼类27种,甲壳类17种,贝类7种,棘皮动物4种,头足类3种,多毛类1种;春季捕获35种渔获物,夏季36种,秋季37种;春季平均渔获率(质量)为3.50 kg/h,夏季为13.68 kg/h,秋季为16.99 kg/h.研究表明:(1)渔获率及其组成季节差异明显.在生物量上,春季以头足类为主,鱼类与甲壳类次之;夏季甲壳类为主,鱼类次之;秋季鱼类为主,甲壳类次之.(2)渔获率空间分布季节变化明显,春季浅水区较深水区渔获率高,夏季深水区较浅水区高.(3)优势种季节变化不明显.(4)春季H'高于夏、秋季,深水区总体高于近岸浅水区.(5) ABC曲线分析可知,群落受到严重干扰.

Based on 496 specimens of Harpodon nehereus collected from Zhoushan Fishery in China in September to November, 2011 and March to May, 2012, morphological characters of the right otoliths were measured and analyzed by principal component analysis, regression analysis, etc. The results showed that the otoliths were irregular oval; the rostrum of otoliths was long and the anti-rostrum was underdeveloped; the end of otoliths had ripple leafed aragonite crystal without postrostrum and pararostrum. The morphological parame-ters (L, H, L1, L3, b2, c1, c2) could represent the most of H. nehereus′ otolith morphology. They and body length (or net weight) were positive correlation and the correlation of L and body length (or net weight) were the most strong. The ratios of the otolith parameters to the long axial length were no obviously correlate with body length. Otolith morphology of H. nehereus was stable during growth and development.

In order to set forth the situation of intertidal macrobenthos resources in Wenzhou, the species composition, quantity distribution, dominant species, biodiversity and ABC curve were analyzed based on the investigation of macrobenthos at 6 sections in the intertidal zone in autumn of 2012, combined with the data from the past. The results showed that:(1) A total of 16 orders, 31 families and 45 species were identified, species of crustacean and mollusk are the most.(2) Biomass and abundance were generally low, crustacean were the dominant in tidal flats areas, while mollusk were the dominant in rocky areas. Biomass and abundance were much higher in rocky areas than that of tidal flat areas.(3) Metaplax longipes was dominant species in all the sections of tidal flat areas, while Thais clavigera was dominant species in ones of rocky areas.(4) The biodiversity level of T3(Cangnan), T5(Dongtou) was high, the community structure had been affected lightly, and their community stability was good. While the biodiversity level of T2(Pingyang), T6(Dongtou)was low, the community structure had been affected seriously, and community stability was poor. Therefore, the marine development departments should utilize the macrobenthos resources reasonably, repair the littoral sea ecology as well as manage the littoral sea resources scientifically at the same time.