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1.
To examine whether fish were dependent on mangrove habitat in the Ryukyu Islands (southern Japan), fish assemblage structures were compared on the downstream side between mangrove-rich and mangrove-free rivers on Ishigaki and Okinawa Islands in 2014 and 2015. The mean species richness and abundance of fish were significantly higher in mangrove-rich rivers than in mangrove-free rivers. Mangrove-related food feeders (e.g., benthic invertebrate and detritus) were more abundant in mangrove-rich than mangrove-free rivers while mangrove-unrelated food feeders (e.g., zooplankton feeders) showed no difference between river types. Cluster and ordination analyses demonstrated that fish assemblage structures were clearly different between mangrove-rich and mangrove-free rivers. Of all of the fish species collected (88 species), half of the species (45 species, 51%) occurred exclusively in the mangrove-rich rivers, 9 species (10%) in the mangrove-free rivers and 34 species (39%) were common in both types of rivers. Commercially important fish (e.g., Lutjanus fulvus and L. argentimaculatus) showed greater abundance of juveniles in mangrove-rich rivers than in the mangrove-free rivers, indicating that mangrove-rich rivers can provide important habitat for a variety of fish, including those commercially important to fisheries. 相似文献
2.
To determine the effects of shore-parallel offshore breakwaters on the surf-zone fish assemblage structure of a sandy beach,
three study sites (sheltered inshore of breakwater, between adjacent breakwaters, and exposed without breakwaters) were sampled
at Ohnuki Beach in Tokyo Bay, central Japan, in September and December 2009 and March and June 2010. Although some physical
variables (wave height, turbidity, and water depth) differed among the three sites, no differences were apparent among the
sites in the numbers of fish species and individuals, or in the abundance of epibenthic invertebrates (a main fish prey).
In addition, species and individual numbers of two dominant feeding groups (mysid and copepod feeders) showed no significant
among-site differences. Cluster and ordination analyses confirmed the similarity in fish species composition among the three
sites. Furthermore, the mean standard length of all fishes collected throughout the study period did not differ significantly
among the sites, the overall results indicating that the presence of breakwaters had little effect on surf-zone fish assemblage
structure in the study area, despite some breakwater-related differences in the abiotic environment. 相似文献
3.
Saori Tatematsu Seiji Usui Takahiro Kanai Yuichi Tanaka Wataru Hyakunari Seiya Kaneko Kouki Kanou Mitsuhiko Sano 《Fisheries Science》2014,80(3):555-568
To determine the effects of artificial headlands (groins with an anchor-shaped head portion) on the surf-zone fish assemblage structure of a sandy beach with strong wave action, three study sites (headland site sheltered behind the head portion, pocket-beach site between two adjacent headlands and exposed reference site without headlands) were sampled on the Kashimanada Coast, central Japan, in summer and autumn in 2012 and 2013. Distinct differences in physical conditions were recognized between the headland site and the other two sites throughout the study period, the former being characterized by lower wave height and turbidity, finer sediment particles and richer detritus. The fish assemblage structures also differed among the sites, the headland site supporting greater species and individual numbers. Cluster analysis showed clear differences in species composition of fish assemblages between the headland site and the other two sites. In addition, small-sized fishes tended to be more abundant at the headland site compared with the other two sites, although no differences were apparent in fish assemblage structure between the pocket-beach and reference sites. These results suggested that the presence of headlands had marked effects on the surf-zone fish assemblage structure in the study area. 相似文献
4.
Toshihiro Yokoo Kouki Kanou Masato Moteki Hiroshi Kohno Prasert Tongnunui Hisashi Kurokura 《Fisheries Science》2012,78(2):237-247
We describe the assemblage structures and spatial distributions of juvenile and adult small gobioid fishes in a mangrove estuary
in Trang Province, southern Thailand. The 11,183 gobioid juveniles and adults collected during the present study were classified
into three families, 19 genera and 36 species. The three most dominant species were Pandaka
pygmaea, Acentrogobius kranjiensis and Acentrogobius malayanus, which accounted for 75.9, 15.0 and 3.8% of the total number of gobioids collected, respectively. Spatial differences in
gobioid fish assemblages were found in a mangrove estuary and its adjacent marine area. The diverse gobioid fauna with a variety
of lifestyles found at muddy-bottomed, low-salinity stations, which were mainly upper- and middle-reach stations, can be partly
accounted for by the existence of the various microhabitats in muddy-bottomed areas around mangroves. These microhabitats
may contribute to local fish catches because gobies are of great significance as prey species for piscivores, including commercially
important fish in mangrove estuaries. The abundance of each gobioid species would contribute to the development of rational
methods for assessing the effectiveness of mangrove conservation and rehabilitation programs. 相似文献
5.
Kusuto Nanjo Hiroyoshi Kohno Yohei Nakamura Masahiro Horinouchi Mitsuhiko Sano 《Fisheries Science》2014,80(1):21-41
In order to clarify the mechanisms determining fish distribution patterns in a mangrove system on Iriomote Island, in southern Japan, fish assemblage structures were determined by visual observation, along with food abundance and environmental factors, in an area of mangrove roots on the banks, and a bare sand area at the center, within downstream, midstream and upstream portions of a branch creek from the Urauchi River. The fish assemblage structures differed significantly between the area types, with the mangrove-root area supporting a more diverse and abundant fish fauna. A canonical correspondence analysis revealed that the relationships between fish distribution and their food abundance differed among trophic groups. Benthic crustacean or plant feeders were positively associated with their prey i.e. crabs and macroalgae—in other words, these trophic groups were abundant in downstream and/or midstream mangrove-root areas in which their prey were also particularly abundant. However, zooplankton feeders did not show such relationships, their abundance being positively associated with fine sediment particles (characteristic of areas with weak water movement). These results suggested that food availability is a major factor determining the distribution patterns of benthic crustacean feeders and plant feeders, whereas for zooplankton feeders other factors, such as sheltering effects against water current and/or predators, may be more significant. 相似文献
6.
The food habits of 67 fish species collected from the mangrove estuary of the Urauchi River, Iriomote Island, southern Japan
were investigated using gut content analysis. Ontogenetic changes in food preference were recognized in nine species, including
mugilids, gerreids, mullids, gobiids and tetraodontids. In most cases, juveniles of these species fed mostly on small crustaceans
(e.g. calanoid and cyclopoid copepods and gammaridean amphipods) or detritus. With their subsequent growth, larger prey items
(e.g. crabs and polychaetes) became dominant. A cluster analysis based on dietary overlaps showed that the mangrove fish assemblage
comprised eight trophic groups (zooplankton, small benthic crustacean, large benthic crustacean, polychaete, fish, detritus,
plant and insect feeders). Of these, large and small benthic crustacean feeders, which consumed mainly crabs and gammaridean
amphipods, respectively, were the most abundantly represented in terms of species, whereas polychaete and insect feeders were
each represented by only two species. 相似文献
7.
The diets and feeding guild structure of a freshwater reed belt fish assemblage (30 species) were examined in Lake Kitaura, part of the Lake Kasumigaura system, eastern Japan, from June to September in 2009 and 2010. Ontogenetic dietary shifts were recognized in 14 species, including several species (e.g., Cyprinus carpio, Tridentiger brevispinis and Hyporhamphus intermedius) targeted by local fisheries. Juveniles of these species generally fed on zooplankton, later switching to other prey items (e.g., benthic chironomid larvae, gammaridean amphipods, shrimps, juvenile fishes, diatoms and decomposing reeds) with growth. A cluster analysis based on dietary overlaps showed that the reed belt fish assemblage comprised five feeding guilds (plant, zooplankton, benthic invertebrate, terrestrial insect and fish feeders). Of these, zooplankton feeders were the most abundantly represented in terms of species numbers, suggesting that the main food items for the fish assemblage were zooplankton (e.g., cladocerans, and calanoid and cyclopoid copepods). Fish feeders included five species, of which one was an alien species introduced from another region in Japan (Opsariichthys uncirostris) and three were from foreign countries (Micropterus salmoides, Lepomis macrochirus macrochirus and Ictalurus punctatus). 相似文献
8.
长江芜湖江段鱼类多样性及其群落结构的时空格局 总被引：4，自引：0，他引：4
为制定合理的渔业资源保护措施与管理对策,2009年按季度共4次调查了长江芜湖江段鱼类多样性及其群落结构。结果显示:该江段现有鱼类54种,其中以似鳊(Parabramis pekinensis)、油(Hemiculter bleekeri bleek-eri warpacho)、短颌鲚(Coilia brachygnathus Kreyenberg et Pappenheim)、鲫(Carassius auratus)等中小型鱼类为常见种和优势种,表明了该江段的鱼类组成存在明显的小型化特点。长江干流沿岸浅水区的鱼类多样性最高,江心深水区最低,而青弋江支流、漳河支流和漳河河口的居中,青弋江的鱼类种数和个体数都显著低于沿岸浅水区,但漳河的鱼类数量与沿岸浅水区无明显差异。江心深水区的鱼类群落与其它样点明显不同,而青弋江的鱼类群落与沿岸浅水区、漳河及其河口的鱼类群落也存在部分差异。鱼类群落结构的季节动态无显著性。 相似文献
9.
E. J. Hyslop 《Ecology of Freshwater Fish》1999,8(2):102-107
Abstract– Longitudinal variation in fish species composition at various sites on the Angabanga river showed an increase in diversity from source to mouth and that only a few fish species occur at all sites. The fish assemblage of floodplain pool areas contained fewer species than the main channel and was dominated by two exotic species Oreochrornis mossambicus (Peters 1852) and Trichoguster pectoralis (Regan 1910). Most native fish species utilize invertebrates as a food source. The absence of indigenous detritus/substrate feeders in the Angabanga community may account in part for the success of the two introduced species on the floodplain. 相似文献
10.
J. Schaefer B. R. Kreiser C. Champagne P. M. Mickle D. D. Duvernell 《Ecology of Freshwater Fish》2009,18(3):360-368
Abstract – Two ecologically similar topminnow species ( Fundulus olivaceus and F. euryzonus ) were studied in a contact zone in the West Fork of the Amite River of the Lake Pontchartrain drainage. We assessed whether relative abundance and measures of fitness of each species, and their hybrids, were correlated with predictable abiotic or biotic factors. We sampled the full fish assemblage and measured a suite of local and landscape level environmental characteristics at ten sites. Topminnows were genotyped to identify individuals of hybrid ancestry. We compared the abundance and distribution of parental species in the context of overall fish assemblage structure and environmental variables. Hybridisation was generally rare with only nine of 244 genotyped topminnows exhibiting evidence of hybrid ancestry. The relative abundance of the two topminnows was related to site assemblage structure, species diversity and a number of local but not landscape level environmental variables. Both species were in better condition and females were more fecund at sites with greater abundance of F. olivaceus . Hybrid individuals were not morphological or ecological intermediates. 相似文献
11.
Jurgenne H Primavera Joseph B Binas Giselle P B Samonte‐Tan Ma Junemie J Lebata Veronica R Alava Mark Walton Lewis LeVay 《Aquaculture Research》2010,41(8):1211-1220
Brackishwater pond culture has been a major factor in mangrove loss in Southeast Asia, hence, the need to develop environment‐friendly technologies such as mud crab Scylla (Portunidae) culture in mangrove pens exists. This study evaluated the effects of mud crab netpen systems in central Philippines on mangrove macroflora, and the replacement of dietary fish with low‐cost pellets. Wild or hatchery‐sourced Scylla olivacea and Scylla serrata were stocked at 0.5–0.8 m−2 in 167–200 m2 nylon netpens (2.3 cm stretched mesh) in Avicennia‐dominated mangrove habitats. The feeding treatments were: (A) Zarraga: (1) no feeding (natural productivity), (2) no feeding for 1 month+supplementary feeding, (3) fish biomass and (4) low‐cost pellets, and (B) Batan: (1) fish biomass and (2) pellets+fish biomass. Feeds were given ad libitum twice daily. Growth and survival rates of S. olivacea in Zarraga pens were not significantly different among treatments, although crabs fed fish biomass had the highest survival, body weight and production. Similarly, growth and survival of S. serrata were not significantly different between the Batan treatments. Economic analysis of the latter gave a 38.5% return on investment (ROI) and 2.6 years payback period (PP) for pellets+fish biomass treatment compared with 27.5% ROI and 3.6 years PP for fish alone. Sensitivity analysis showed an improved economic performance of the pellets+fish biomass treatment by increasing the survival rate. Evaluation of mangrove community structure showed that crab culture reduced species diversity, numbers and biomass of seedlings and saplings, but not of mangrove trees. Therefore, mud crab pen culture is recommended for mangrove sites with mature trees, but not seedlings and saplings, and low‐cost pellets can reduce dependence on fish biomass. 相似文献
12.
The interstices of coral rubble provide a good refuge for cryptic small crustaceans and molluscs, which are important prey
items for reef fishes. In this study, we focused on the assemblage composition of cryptic mobile species along the depth gradient
at an outer reef slope. Traps with coral rubble (22 × 18 × 6 cm) were set at three sites at different depths, and mobile animals
that colonized the traps were sorted. In total, 117 species of larger animals (mainly Decapoda and Gastropoda) were recorded:
71 species at the 3 m point, 53 species at the 11 m point, and 37 species at the 22 m point. On average, 260.3 individuals
were captured in the traps at 3 m, while 95.3 and 57.8 individuals were captured at 11 and 22 m, respectively. MDS ordination
showed that assemblage composition differed among the three sites. The most abundant species at the 3 m was the galathean
crab Galathea mauritiana, followed by the gastropod Diala albugo. At 11 and 22 m, the galathean crab Sadayoshia edwardsii was most abundant. Thus, at the reef slope, the benthic assemblage was most diverse at the shallow site, and specific communities
occurred at the three sites. 相似文献
13.
Masahiro Horinouchi Prasert Tongnunui Kusuto Nanjyo Yohei Nakamura Mitsuhiko Sano Hisao Ogawa 《Fisheries Science》2009,75(6):1409-1416
Fish assemblage structures in fragmented and continuous seagrass habitats in Trang Province, Thailand, were examined in detail
to elucidate the effects of habitat fragmentation. The assemblage structures clearly differed: fish species diversity was
apparently higher in the fragmented seagrass beds, although total fish numbers did not differ between them. A total of 37
fish species were collected, including 24 and 34 species from the continuous and fragmented beds, respectively. Thirteen species
were restricted to the fragmented beds, compared with three restricted to the continuous beds. In addition, eight species
were more abundant in the fragmented beds and only two in the continuous beds. Such differences may have arisen, at least
in part, from differences in microhabitat diversity and the relative amounts of microhabitats between the two habitat types,
as well as specific microhabitat preferences of the resident fishes. Although fragmented beds supported greater fish species
diversity at the present study sites, it is axiomatic that habitat fragmentation caused by anthropogenic disturbance is unacceptable,
with seagrass-habitat conservation being essential for both the preservation of high overall biodiversity and the successful
management of local fisheries. 相似文献
14.
Dietary overlap and selectivity among silver carp and two native filter feeders in the Wabash River 
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下载免费PDF全文 Silver carp (Hypophthalmichthys molitrix) are a potential threat to native filter feeders and larval fish due to dietary overlap. To test for dietary overlap and selectivity, we collected diet samples from invasive silver carp and two native filter feeders (gizzard shad Dorosoma cepedianum and bigmouth buffalo Ictiobus cyprinellus), and river plankton samples at three sites on the Wabash River during the spring and summer of 2015. Contents of diet items were identified to major group and quantified. Diet proportions were compared among seasons, sites and species. Diet selectivity was calculated using the Manly–Chesson diet selectivity index. The results of our diet analysis showed that silver carp had significantly dissimilar diets among seasons and displayed dietary overlap with native fishes. We did not find a significant difference among sample sites. While silver carp diets overlapped with native fishes, the impact of this possible source of competition requires further study to confirm impacts on native fish abundances and body conditions. 相似文献
15.
The annual dynamics of fish assemblage in a pond-connecting canal of a South Moravian pond aquaculture facility was studied
to reveal potential assemblage effects on pond stocks and vice versa. The species richness of fish assemblage and seasonal
dynamics of its development were predominantly dependent upon the fish stock of the interconnected ponds (particularly due
to escapees during the period of pond harvesting), which contributed to a considerable increase of commercial fish species
occurrence. Using a seasonal parameter, the season proved to have a major impact on fish assemblage dynamics (r = −0.71, P < 0.001). Spring samples were dominated by commercial fishes of aquaculture origin (mainly Cyprinus carpio). Occurrence of several fish species originating from the wild (bleak, Alburnus alburnus, chub, Leuciscus cephalus and roach, Rutilus rutilus) was also reported.
The pond canal was found to be an important reservoir site of persistent survival and potential subsequent spreading of some
undesirable alien fishes such as topmouth gudgeon (Pseudorasbora parva) and gibel carp (Carrasius auratus). Moreover, more attention should be paid to the potential negative impacts of all fishes of aquaculture origin upon the
natural ecosystem and to the adverse effects due to the immigration of wild fish into aquaculture pond farming units. 相似文献
16.
Nicholas T. Simpson Alexander P. Bybel Michael J. Weber Clay L. Pierce Kevin J. Roe 《水产资源保护:海洋与淡水生态系统》2021,31(7):1831-1846
- Many fish species of greatest conservation need (SGCN) in Iowa and Minnesota, USA, have been in decline for decades. A key reason for the decline is the alteration and degradation of naturally flowing streams owing to land use changes resulting from agricultural practices. Populations of several fishes have been adversely affected by widespread stream channelization that has resulted in more homogeneous stream habitats throughout Iowa and Minnesota.
- The goal of this study was to determine the abiotic and fish assemblage characteristics associated with the presence of these rare fishes. Electrofishing and seining were used to sample fish assemblages and 43 abiotic characteristics were measured at 111 sites in the North Raccoon and Boone River basins in central Iowa and the Rock River and Beaver Creek basins in north-west Iowa and south-west Minnesota during 2016 and 2017.
- Six SGCN, including the federally endangered Topeka shiner (Notropis topeka), were included in statistical modelling to determine habitat and fish assemblage characteristics associated with their presence.
- Species-specific nonmetric multidimensional scaling ordinations indicated that abiotic characteristics and fish assemblages often differed between sites where SGCN were present and absent. Random forest and logistic regression models suggested that the presence of four of six SGCN were positively associated with species richness, whereas all other 10 important abiotic and fish assemblage variables were unique to only one or two of the six SGCN.
- Topeka shiners were present at 36% of sites and were positively associated with orangespotted sunfish (Lepomis humilis) catch per unit effort while being negatively associated with canopy cover and fantail darter (Etheostoma flabellare) catch per unit effort.
17.
Potential population and assemblage influences of non‐native trout on native nongame fish in Nebraska headwater streams 下载免费PDF全文
下载免费PDF全文 Kelly C. Turek Mark A. Pegg Kevin L. Pope Steve Schainost 《Ecology of Freshwater Fish》2016,25(1):99-108
Non‐native trout are currently stocked to support recreational fisheries in headwater streams throughout Nebraska. The influence of non‐native trout introductions on native fish populations and their role in structuring fish assemblages in these systems is unknown. The objectives of this study were to determine (i) if the size structure or relative abundance of native fish differs in the presence and absence of non‐native trout, (ii) if native fish‐assemblage structure differs in the presence and absence of non‐native trout and (iii) if native fish‐assemblage structure differs across a gradient in abundances of non‐native trout. Longnose dace Rhinichthys cataractae were larger in the presence of brown trout Salmo trutta and smaller in the presence of rainbow trout Oncorhynchus mykiss compared to sites without trout. There was also a greater proportion of larger white suckers Catostomus commersonii in the presence of brown trout. Creek chub Semotilus atromaculatus and fathead minnow Pimephales promelas size structures were similar in the presence and absence of trout. Relative abundances of longnose dace, white sucker, creek chub and fathead minnow were similar in the presence and absence of trout, but there was greater distinction in native fish‐assemblage structure between sites with trout compared to sites without trout as trout abundances increased. These results suggest increased risk to native fish assemblages in sites with high abundances of trout. However, more research is needed to determine the role of non‐native trout in structuring native fish assemblages in streams, and the mechanisms through which introduced trout may influence native fish populations. 相似文献
18.
Shun Kawaida Kusuto Nanjo Takahiro Kanai Hiroyoshi Kohno Mitsuhiko Sano 《Fisheries Science》2017,83(6):1007-1017
Crab assemblage structures in sandy flat, muddy flat and mangrove forest microhabitats in a mangrove estuary of the Urauchi River, Iriomote Island, southern Japan, differed clearly among the three microhabitats, species and individual numbers being greater inside the mangrove forest than on the flats. A similarity index showed distinct differences in species composition among the microhabitat assemblages, primarily due to the differential distributions of dominant species, such as the soldier crab Mictyris guinotae, sentinel crab Macrophthalmus convexus and sesarmid crab Perisesarma bidens. A canonical correspondence analysis indicated that the differences likely arose from among-microhabitat differences in the physical environment, the mangrove forest being characterized mainly by structurally complex mangrove roots, lower soil porewater temperatures and higher relative substrate elevation, the sandy flat by lower organic content of the sediment and higher porewater oxygen amount, and the muddy flat by higher levels of sediment water and organic material. The findings suggested that microhabitat-related physical differences are important factors determining crab distribution patterns in mangrove estuaries. 相似文献
19.
为探究不同时空尺度下黄河口及其邻近水域鱼类群落谱系结构的分布格局以及多样性的维持机制, 根据 2013 年 6 月、7 月、8 月、10 月和 2014 年 2 月、4 月和 5 月在黄河口及其邻近水域开展的 7 个航次的鱼类资源调查数据, 基于鱼类系统发育关系, 分别以各月份黄河口及其邻近水域的鱼类群落、全年和不同月份在各个站位上出现的鱼类为目标群落, 应用净亲缘关系指数分析了该海域鱼类群落谱系结构的时空变化, 并探讨了影响群落构建的主要因素。结果表明, 在黄河口及其邻近水域, 鱼类群落谱系结构在 2 月、4 月呈现发散状态, 竞争排斥可能是影响鱼类群落构建的主导因素; 在其他月份均为谱系聚集状态, 生境过滤可能是鱼类群落构建的主导因素。在站位尺度上, 从全年来看, 入海口处的站位点鱼类群落呈现为谱系发散, 竞争排斥起着主导作用, 而其他站位鱼类群落谱系结构表现为谱系聚集, 生境过滤为主要驱动因素; 在各月份中, 站位间鱼类净亲缘关系指数变化较小, 除 2 月和 4 月外, 各月份中多数站位上鱼类群落表现为谱系聚集, 生境过滤起着主导作用。不同时空尺度下, 黄河口及其邻近水域鱼类群落有不同的物种组成和谱系结构; 在较大时空尺度下, 生境过滤对鱼类群落谱系结构起主导作用, 而在较小时空尺度下竞争排斥则是主要影响因素。 相似文献
20.
Movement and recaptures of two hatchery-reared brown trout, Salmo trutta L., stocks and landlocked salmon, Salmo salar L., released at different sites in regulated Lake Oulujärvi, were studied in relation to release site. Five groups of fish from each stock were released in approximately equal numbers. Most of the fish released in June and July were recaptured within 3 months, whereas the majority of the fish released in early winter (October and November) were caught the following spring, about 7–9 months after stocking. The release site had a significant effect on recapture rate. The results showed that fishing restrictions targeted mainly at gill net fishing are needed to preserve the stocked fish from overfishing. Significantly fewer recaptures were observed from the landlocked salmon stocking compared with brown trout. The recaptures from the landlocked salmon stocking indicated more active movement and less clumping compared with the two brown trout stocks. 相似文献