scholarly journals 18S rRNA metabarcoding diet analysis of a predatory fish community across seasonal changes in prey availability

2019 ◽  
Vol 9 (3) ◽  
pp. 1410-1430 ◽  
Author(s):  
Justin M. Waraniak ◽  
Terence L. Marsh ◽  
Kim T. Scribner
2004 ◽  
Vol 61 (3) ◽  
pp. 414-431 ◽  
Author(s):  
Yunne-Jai Shin ◽  
Philippe Cury

For most fish species, strong environmental constraints imposed by living in an aquatic medium have produced converging streamlined body forms without prehensile appendices. This similarity in body shapes highlights a common predation constraint: a predatory fish must have a jaw large enough to swallow its prey. Fish diets may then reflect local prey availability and predator–prey size ratios. Based on this size-based opportunistic predation process, the multispecies individual-based model OSMOSE (Object-oriented Simulator of Marine ecOSystem Exploitation) is used to investigate to what extent the size distribution of fish communities can contribute to better our understanding of the functioning of marine food webs and the ecosystem effects of fishing. Strong similarity in shape is found between simulated size spectra and those described in empirical studies. The existence of a curvature towards small size classes is discussed in the light of the size-based predation hypothesis, which implies that smaller fish may undergo higher predation mortality. Applying linear and quadratic regressions to the simulated size spectra allows the detection of variations in fishing pressure and the proposal of different ways to quantify them. In particular, it is shown that the slope of the size spectrum decreases quasilinearly with fishing mortality and that the curvature could help to detect ecosystem overexploitation.


2017 ◽  
Vol 41 (2) ◽  
pp. 239-253
Author(s):  
Jana Menegassi del Favero ◽  
June Ferraz Dias

In order to analyze the time-space variation of the fish fauna in the surf zone fish communities at Ilha do Cardoso State Park, São Paulo, Brazil, four consecutive hauls were done over a year on three beaches with different degrees of exposure, at low and high tide. To evaluate the influence of each abiotic variable over the fish community, a Canonical Correspondence Analysis was conducted. We identified 7,286 individuals belonging to 20 families and 47 species, most specimens collected were juveniles. At low tide, the highest diversity and richness values were calculated while the highest dominance was obtained at high tide. As for the number of species collected at the three beaches, stood out for the lower values the cooler months, between June and September. Abiotic variables explained 41.3% of the variability of biological data, where 11.4% corresponds to the spatial variation. Meanwhile the temporal variables accounted for 31.9% of the variation in abundance, where 26.3% of the variance explained nycthemeral variation. Additionally two groups were clearly observed between months with low and high temperature. However in this variable, the tidal variation, excluding the seasonal effect, explained 6.2%, while seasonality, excluding tide effect, explained 26.3%. Although the main measurable seasonal changes were related to temperature, water temperature showed a low percentage of explanation in the fish fauna variability (2.7%). Finally, it is emphasized that the seasonal changes in surf zone fish community primarily reflect patterns of recruitment determined by the reproductive activity and coastal circulation.


1989 ◽  
Vol 67 (8) ◽  
pp. 2008-2012 ◽  
Author(s):  
Joseph M. Culp

Diel periodicity in foraging activity of the longnose dace (Rhinichthys cataractae) was determined by measuring dace activity over the stream bed, gut fullness, and the digestive state of prey items. Although most species of minnows are either diurnally or crepuscularly active, dace began foraging within 1 h after sunset with light levels near 10 lx and ceased before sunrise throughout the ice-free period. During the day few prey were taken as the dace remained under the shelter of stones. This nocturnal foraging pattern did not appear to be affected by spawning or seasonal changes in prey composition. Nocturnal foraging in dace is not likely a response to prey availability, but may be a response to avoid diel periods when salmonid competitors or visual predators are active.


1979 ◽  
Vol 6 (1) ◽  
pp. 79 ◽  
Author(s):  
B Miller

The food and feeding habits of two species of cormorant were studied on a group of freshwater lakes in inland New South Wales. P. sulcirostris fed mainly on exotic fish (69% of live weight of prey), captured while fishing communally in the deeper waters. P. melanoleucos fed mainly on native decapod crustaceans (60% of prey) captured while fishing individually in the shallow parts of the lakes, and in nearby billabongs and farm dams. P. sulcirostris took larger common carp Carassius auratus, redfin Perca fluviatilis and yabby Cherax destructor than its congener. Seasonal changes in the diet of P. sulcirostris were similar in each year; its major prey, common carp and redfin, were least available during winter and spring, as fry grew too large to be captured and swallowed. Changes in diet of P. melanoleucos were irregular, as the availability of yabby, its major prey, was influenced by the turbidity, level and temperature of water. Seasonal changes in diets of both cormorants were attributed to changes in prey availability, and not changes in food preference. Food of nestlings sometimes differed from that of adults.


2018 ◽  
Vol 75 (10) ◽  
pp. 1723-1732 ◽  
Author(s):  
Diana Perry ◽  
Thomas A.B. Staveley ◽  
Linus Hammar ◽  
Alyssa Meyers ◽  
Regina Lindborg ◽  
...  

In shallow-water marine environments, ecosystem functioning is a complex interworking of fine-scale characteristics and region-wide factors, and the importance of these variables can vary on multiple temporal and spatial scales. This underwater video study targeted seasonal changes in the fish community of seagrass habitats along the Swedish west coast and the influence of offshore seascape variables (latitudinal position, wave exposure, open ocean, and deep water). Results showed that fish assemblage structure exhibited seasonal changes between summer and autumn and strong spatiotemporal variations in the importance of offshore factors affecting shallow-water fish communities. In summer, abundance from the Gobiidae family responded to wave exposure, whereas the Gadidae family and juvenile migrant habitat preference guild responded to latitudinal position and proximity to deep water. In autumn, deep water was related to abundance of Gadidae and juvenile migrants, whereas latitudinal position influenced Gasterosteidae. These findings underscore the importance of understanding the influence of offshore factors on facets of coastal fish assemblages to address large-scale geographic connectivity along nearshore–offshore gradients.


2014 ◽  
Vol 34 (7) ◽  
Author(s):  
李凡 LI Fan ◽  
徐炳庆 XU Bingqing ◽  
马元庆 MA Yuanqing ◽  
吕振波 LU Zhenbo ◽  
王田田 Wang Tiantian

2000 ◽  
Vol 57 (8) ◽  
pp. 1679-1691 ◽  
Author(s):  
Lance P Garrison

Patterns in spatial and trophic resource partitioning in the fish community of the Georges Bank region are identified, accounting for size-based changes in diets. During autumn and spring, this community is divided into geographic assemblages of species that have high spatial overlap. Similarity in spatial distribution is primarily related to similarity in depth preferences, and seasonal differences in species composition within assemblages are related to migrations. There is also important trophic structure within the Georges Bank community separating predators based upon prey size and location in the water column. Ontogenetic changes in diets are an important feature of the trophic structure in this system, particularly in the major piscivores. Seasonal changes in trophic structure reflect both predator and prey migrations. Dietary overlap among predator types is independent of either spatial overlap or depth preferences. There is spatial segregation within trophic guilds, and this spatial partitioning reduces the potential for exploitative competition within this community. Given the observed spatial patterns in trophic structure, the geographic assemblages on Georges Bank may be considered ecologically distinct functional units within this ecosystem.


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