Spatial and seasonal variations in fish assemblages of the Yangtze River estuary
Summary This study aimed to test the hypothesis that biotic influences play a role in determining estuarine fish assemblages. Thus the mechanisms that regulate the observed spatial niche segregation between fish species with morphological and ecological similarities within estuaries were investigate...
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Published in | Journal of applied ichthyology Vol. 30; no. 5; pp. 844 - 852 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Berlin
Blackwell Publishing Ltd
01.10.2014
Wiley Subscription Services, Inc |
Subjects | |
Online Access | Get full text |
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Summary: | Summary
This study aimed to test the hypothesis that biotic influences play a role in determining estuarine fish assemblages. Thus the mechanisms that regulate the observed spatial niche segregation between fish species with morphological and ecological similarities within estuaries were investigated. Fishes were sampled seasonally at 30 stations along an entire salinity gradient of the Yangtze River estuary from spring 2010 to winter 2011, using bottom trawling (10 mm mesh size in the cod end). A total of 62 species belonging to 28 families were collected. Marine migrants (21) and estuarine species (19) dominated the assemblage and accounted for the highest abundances (marine migrants = 42.5%, estuarine species = 38.3%), with the marine migrants having the highest biomass (57.2%). Canonical correspondence analyses indicated that chlorophyll a, salinity, temperature, and geographic distance were the four main variables influencing the occurrence of fishes within the system. A stable fish assemblage in the upper zone during the wet season (spring and summer) was more obvious than in the dry season. The Pianka index showed a clear spatial segregation in four pairs of tonguesoles species (Cygonobius), and in most pairs of gobiids (Gobiidae), and a high degree of overlapping (>0.60) in only four pairs of gobiid species during the wet season. However, according to the results of the null model the observed segregating or pattern sharing was not caused by interspecific competition. |
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Bibliography: | istex:005B341AAAFF1AFE0B879022F1BB9A708160FD77 ArticleID:JAI12448 ark:/67375/WNG-KHPJJ1G5-S State Key Development Program for Basic Research in China - No. 2010CB429005 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0175-8659 1439-0426 |
DOI: | 10.1111/jai.12448 |