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1.
Effect of siltation on stream fish communities 总被引:10,自引:0,他引:10
Synopsis The effect of siltation on stream fish in northeast Missouri was evaluated using community structural measurements and a functional
approach that emphasized feeding and reproductive guilds. As the percentage of fine substrate increased, the distinction among
riffle, run, and pool communities decreased, primarily because the number of individuals of typical riffle species decreased.
Within the riffle communities the abundance of fish of two feeding guilds — benthic insectivores and herbivores — was reduced
as the percent of fine substrate increased. The abundance of fish in other feeding guilds was not affected. The only reproductive
guild to be similarly affected was the simple and lithophilous, whose members require a clean gravel substrate for spawning.
Species within each guild affected by siltation had significantly similar trends in abundance. The guild analysis indicated
that species with similar ecological requirements had a common response to habitat degradation by siltation. 相似文献
2.
V. V. Napazakov 《Russian Journal of Marine Biology》2008,34(7):452-460
The food spectra, trophic statuses, and feeding interrelations of three most abundant benthic carnivorous fish species inhabiting
the Shelikhov Bay—the Pacific cod Gadus macrocephalus, the great sculpin Myoxocephalus polyacanthocephalus, and the Okhotsk sculpin M. ochotensis—are considered based on materials collected during the complex survey of the RV Professor Kaganovsky of the TINRO-Center, in September 2004. It was found that these species were facultative predators with wide food spectra.
The significance of prey objects in the diet of the Okhotsk sculpin was as follows: crustaceans, fish, and mollusks. Great
sculpin and Pacific cod preyed mostly on fish, then on crustaceans, and mollusks. Pacific cod ate equal proportions of fish
and decapods. All the species had age-related variability of diet. The potential competition of great sculpin and Okhotsk
sculpin for food was mitigated by the difference in the depths of their ranges, as well as by morphological (body size) and
behavioral peculiarities in the areas where their habitats overlapped, and in microecosystems. The most probable competition
was among Pacific cod 30–60 cm long and Okhotsk sculpin 20–50 cm in length, as well as among cod and great sculpins of all
sizes. 相似文献
3.
Amir Neori 《Journal of applied phycology》2011,23(1):143-149
Freshwater fish culture is generally considered the largest sector in world aquaculture. Several of the leading species consume
“green water” plankton. This plankton—mostly microalgae (phytoplankton) and also bacteria, protozoa and zooplankton—grows
in man-made fertilized water impoundments. The quantity of “green water” microalgae consumed by fish and shrimp is estimated
here at a quarter billion ton fresh weight a year, about three and a half times as much as the entire recognized aquaculture.
This estimate is based on the quantities of the microalgae consumed and the efficiencies of their use for growth by the main
species in aquaculture. The cost of producing “green water” microalgae by the aquaculturists—mostly in SE Asia—is low. The
populations in “green water” are biologically managed by the cultured fish themselves. The fish with their different feeding
habits help “manage” the composition of the plankton and the overall water quality as they grow. The aquaculturists further
manage “green water” through simple means, including water exchange and fertilization. Cost is remunerated partially by the
income from sales of the fish and partially by bio mitigation services that “green water” polyculture ponds provide the aquaculturists
in treating farm and household waste. A comprehension of the scale and importance of the microalgae sector to world aquaculture
should lead to more research to improve understanding of algal population dynamics, growth factors, and efficiency of food
chains. The consequent improved control of the plankton’s interaction with fish and shrimp production in “green water” will
undoubtedly contribute much to the expansion in production of seafood. 相似文献
4.
Yu. V. Gerasimov 《Inland Water Biology》2008,1(2):175-181
The foraging behavior of four fish species—bream, Abramis brama (L.); roach, Rutilus rutilus (L.); crucian carp, Carassius auratus (L.); and a tropical catfish, Corydoras paleatus (Jenins)—differing in their degrees of morphological specialization for benthic foraging has been studied. In the modeling
of a stable environment, fish encountered a constant pattern of food location, while under unstable conditions, food location
varied between subsequent trials. In contrast to an unstable environment, after long exposures to constant conditions, there
was an increase in motor activity not associated with foraging and the feeding rate fell. This drop in feeding rate resulted
in decreased growth rates in the studied fish. 相似文献
5.
N. T. Dolganova N. V. Kolpakov V. I. Chuchukalo 《Russian Journal of Marine Biology》2008,34(7):482-489
The feeding interrelations and foraging of juvenile fish and shrimp were investigated in estuaries of Peter the Great Bay
in summer and fall 2006 and 2007. In total 3483 specimens were analyzed. The trophic spectra of 34 fish species and 3 shrimp
species were described for the first time. Three trophic groups were singled out depending on differences in diet compositions:
(i) detritophages (3 species of bitterlings—Acanthorhodeus sp., A. chankaensis and Rhodeus sericeus, redlip mullet Liza haematocheila and two species of shrimp-Palaemon macrodactylus and Crangon cf. septemspinosa); (ii) predators (lookup Culter alburnus and Amur catfish Silurus asotus); (iii) euryphages (28 fish species and the shrimp Palaemon paucidens). The detritus food chain was found to be the primary one in estuaries of Peter the Great Bay. Most of the species had two
peaks of feeding activity each day. Values of daily feeding rations were determined for 21 fish species; these varied from
1.6% to 8.0% of body weight. Similarity in diet composition was significant only for 10% of the species, which shows a low
level of competition for food in the community. 相似文献
6.
Ruminant herbivores have been shown to learn about food properties by associating food flavours with the food’s post-ingestive
consequences. Previous experimentation supporting the conditioned food aversion/preference hypothesis has generally employed
very simple diet learning tasks which do not effectively represent the wide range of foods selected within single bouts typical
of wild, free-ranging ruminant herbivores. We tested the ability of a ruminant herbivore to associate a food with artificially
administered nutrient rewards in a designed experiment where we altered the temporal pattern of encounter with the food as
well as the nature (fast or slow reward) of the post-ingestive outcome. Twenty-four goats were offered branches of Sitka spruce
(SS) and Norway spruce (NS) for 4 h per day on two days per week for five weeks. The pattern of feeding varied with treatment such that the species on offer changed every hour (short) or every 2 h (long). The energy treatment altered the reward delivered during Sitka consumption so that animals were dosed either with predominantly sugar
(rapidly fermented), predominantly starch (slower fermentation rate), or with water (placebo). Preference was measured on
the day following each learning day. We expected that goats would find it easier to associate SS with post-ingestive rewards
when the duration of encounter was longest, and that associations would be stronger with the most rapidly digested post-ingestive
reward. In the event, goats did not alter their consumption of SS in response to the treatments. Our results suggest that
at the scale of temporal resolution of encounters with different plant species (1–2 h), and at the different rates of experiencing
post-ingestive consequences tested in this experiment, ruminants do not appear to discriminate the nutritive properties of
foods predominantly through a post-ingestive feedback mechanism. They must, instead, use a range of cues—including post-ingestive
consequences—to assess food properties.
An erratum to this article can be found at 相似文献
7.
Groups of carp and thick lipped mullet quickly learned to operate an underwater trigger for food reward. Single mullet also learned this operant response but single carp did not. Groups of mullet exhibited a higher rate of responding than groups of carp. Mullet appeared to feed in bouts, whereas carp fed randomly during the learning trials. Both species adapted well to six days continuous demand feeding. Grouped and single mullet decreased their feeding at night but carp did not show a diurnal feeding pattern. Feeding responses were found not to be sequences of random events and response rates over the six days were higher in carp than in mullet. In both species, individual fish within a group operated the trigger significantly more often than other fish but all fish took food and gained weight. 相似文献
8.
Researchers consider group size in primates to be determined by complex relationships among numerous ecological forces. Antipredator benefits and better resource defense are the primary pressures for large groups. Conversely, intragroup limited food availability, can result in greater intragroup feeding competition and individual energy expenditure in larger groups, creating energetic advantages for individuals in small groups and placing an upper limit group size. However, the extent to which food availability constrains group size remains unclear for many species, including black howlers (Alouatta pigra), which ubiquitously live in small social groups (≤10 individuals). We studied the relationship between group size and 2 key indices of feeding competition—day journey length and activity budgets—in 3 groups of wild Alouatta pigra at a hurricane-damaged site in Belize, Central America. We controlled for differences in food availability between home ranges (food tree density) and compared both indicators of feeding competition directly with temporal variation in food availability for each group. Our results show no consistent association between resource availability, group size, and either index of competition, indicating that feeding competition does not limit group size at the site—i.e., that larger groups can form without increased costs of feeding competition. The results support the search for other explanations, possibly social ones, for small group size in the primates, and we conclude with suggestions and evidence for such alternative explanations. 相似文献
9.
Goro Hanya 《International journal of primatology》2009,30(4):569-581
It is important to understand the effects of ecological factors on aggression during feeding in order to link habitat characteristics
to competitive regime and social relationships. Multiple habitat characteristics are likely to affect aggression, but few
researchers have examined the effect of multiple factors on intragroup competition simultaneously. I examined the effect of
8 factors on aggression during feeding in wild Japanese macaques living in a coniferous forest in Yakushima: density of the
tree species, feeding time, number of feeding sites within a feeding tree, number of cofeeding animals, intratree macaque
density, food type, and rank and age of the focal individual. When macaques cofed with other individuals, food type, the number
of feeding sites, and their interactions significantly influenced aggression. Aggression increased when macaques ate fruits/seeds
versus other foods and as the number of feeding sites decreased. Primate socioecological models highlight the importance of
clumped distribution of food patches as a correlate of intragroup contest. However, my study indicates that primatologists
need to pay attention to the factors related to the current feeding tree—food type and feeding tree size with respect to monopolizability—in
addition to the distribution of food in the entire home range. 相似文献
10.
N. V. Chernova 《Journal of Ichthyology》2011,51(10):825-924
Chorological structure of ichthyofauna of the Arctic Region is described. Distribution patterns of 504 fish-like vertebrates
and fish species are characterized. One hundred and eighty-nine range types are defined, which are combined into eight main
categories: 1—Arctic; 2—Atlantic-Arctic; 3—transitional subarctic zone of Atlantic sector; 4—Pacific-Arctic; 5—transitional
subarctic subarctic zone of Pacific sector, 6—Pacific-Atlantic (amphiboreal); 7—bipolar; 8—continental (fresh and brackish
waters). Arctic and boreal regions are bordered by transitional (subarctic) zones, which are the areas of intermutual penetration
of faunas. The distribution of most fish species that penetrate into to the Arctic Region from the southern areas is limited
by these transitional zones. The benthic fish species prevail in the group of autochthonous Arctic species (which includes
64 species or 14% of marine fauna). The demersal fauna of the Arctic preudoabyssal is presented by endemic species. Ten variations
of amphiboreal distribution patterns are revealed. Three areas may be defined within the Atlantic-subarctic zone in regard
to the fish fauna and range types, i.e., Labrador-Greenland region, the Barents Sea region, and Icelandic (transitional) region. 相似文献
11.
Weston H. Nowlin Ray W. Drenner Kirk R. Guckenberger Mark A. Lauden G. Todd Alonso Joseph E. Fennell Judson L. Smith 《Hydrobiologia》2006,563(1):357-369
Top–down control of phytoplankton biomass through piscivorous fish manipulation has been explored in numerous ecological and
biomanipulation experiments. Piscivores are gape-limited predators and it is hypothesized that the distribution of gape sizes
relative to distribution of body depths of prey fish may restrict piscivore effects cascading to plankton. We examined the
top–down effects of piscivorous largemouth bass on nutrients, turbidity, phytoplankton, zooplankton and fish in ponds containing
fish assemblages with species representing a range of body sizes and feeding habits (western mosquitofish, bluegill, channel
catfish, gizzard shad and common carp). The experimental design consisted of three replicated treatments: fishless ponds (NF),
fish community without largemouth bass (FC), and fish community with largemouth bass (FCB). Turbidity, chlorophyll a, cyclopoid copepodid and copepod nauplii densities were significantly greater in FC and FCB ponds than in NF ponds. However,
these response variables were not significantly different in FC and FCB ponds. The biomass and density of shallow-bodied western
mosquitofish were reduced and bluegill body depths shifted toward larger size classes in the presence of largemouth bass,
but the biomass and density of all other fish species and of the total fish community were unaffected by the presence of largemouth
bass. Our results show that top–down impacts of largemouth bass in ecosystems containing small- and deep-bodied fish species
may be most intense at the top of the food web and alter the size distribution and species composition of the fish community.
However, these top–down effects may not cascade to the level of the plankton when large-bodied benthivorous fish species are
abundant. 相似文献
12.
Information on the qualitative and quantitative characteristics of the feeding habits of two pandal shrimp—the humpy shrimp
(Pandalus goniurus) and the northern shrimp (Pandalus borealis) and one species of crangonids (Crangon communis) is submitted. The materials were collected in April–May 2006 and 2007 during complex surveys at West Kamchatka. The size
and sex composition of the shrimp, as well as the composition of their food were analyzed. The food of all the considered
species basically consisted of polychaetes, amphipods and, to a lesser extent, other shrimp. The daily ration (DR) of a shrimp
with a body length of 40–60 mm was calculated for the first time—it was 7.9% of the body weight. The DR of a northern shrimp
61–80 mm in length was 5.8% of its body weight. Individuals of the third species, Crangon communis, generally did not feed. 相似文献
13.
Feeding experiment on nine feral minkMustela vison Schreber, 1777 was carried out to find differences in digestibility of particular prey types. The values of correction factors
(CF), which show the ratio between consumed prey biomass and undigested remains, were calculated for seven food types. The
experiment revealed that results obtained by commonly used percentage of occurrence methods differed from the real intake
of food. Food types which were intensively digested were underestimated by percentage of occurrence methods and prey which
had hardly digestive elements of their body were overestimated. The calculated values of CF are as follows: crayfish — 14.8,
fish — 30.8, frog — 61.3, small passerine bird — 17.2, chicken — 41.3, rodent — 17.3, egg — 687.5. The variability in CF values
did not depend on mink individuals but could be explained by the mean weight of prey items eaten by mink. The positive correlation
between the prey size and its digestibility was recorded for crayfish, fish and chicken. The biomass of frog, passerine and
rodent remains was not related to the body mass of eaten prey. The use of evaluated correction factors enables more accurate
estimates of the food composition of wild living mustelids. 相似文献
14.
Experiments were performed to investigate senses that are essential for mediating fright reaction and food behavior in Pseudoplatystoma corruscans, pintado. The dilemma “to feed or to flee” was also analyzed in fishes with intact and sectioned olfactory tracts, stimulated
by alarm substance extracts and food. Fishes were arranged into five groups: fish with intact lateral olfactory tracts (LOT),
fish with intact medial olfactory tract (MOT), fish with tracts totally sectioned (TOTAL, both LOT and MOT), sham operated,
and nonoperated fish. The five groups were submitted to either alarm substance extract and food stimulus or to distilled water
(control) and food stimulus. Fish reacted to food independently of which tract (LOT, MOT or TOTAL) was sectioned; vision seems
necessary and elemental to detect and deflagrate food response. Latency of the responses to each reaction was different between
groups. None of the fish with sectioned tracts reacted to alarm substance extract, while sham- and nonoperated fish showed
the typical alarm behavior response, leading to the conclusion that olfaction is essential for mediating alarm response. These
results indicate that others sense systems (e.g., vision) are sufficient to trigger and elicit feeding behavior and that olfaction
is not necessary to fully maintain food detection to qualitative and quantitative extent. However, olfactory tract integrity
seems to be required for mediation of alarm reaction in P. corruscans. 相似文献
15.
The grazing rates and feeding preferences of the dinoflagellates Pfiesteria piscicida and a cryptoperidiniopsoid on the alga Rhodomonas sp. and fish blood cells were calculated at different ratios of the two food types and at different total food densities. Data from 6 h grazing periods within microcosms were used to calculate grazing rates. Grazing rates of both dinoflagellates increased linearly with an increased ratio of blood cells to Rhodomonas, and P. piscicida had a higher maximum grazing rate than the cryptoperidiniopsoid. The grazing rate of P. piscicida on Rhodomonas also increased with increased Rhodomonas densities relative to the blood cells, but increased densities of Rhodomonas did not increase the grazing rate of the cryptoperidiniopsoid, suggesting a lower feeding threshold for this species. Both dinoflagellates demonstrated a preference for fish blood cells over Rhodomonas cells, with no significant difference in the index of preference between the two species. Total food abundance affected the degree of preference differently for each dinoflagellate species. A higher index of feeding preference was attained by P. piscicida when resource levels were high, while the cryptoperidiniopsoid did not show this response. A preference for fish blood cells occurred at all food ratios for both dinoflagellates, including when blood cells were scarce relative to the alternate food type (15% of total available food). These results suggest that these strains of P. piscicida and the cryptoperidiniopsoid share similar feeding preferences for the prey types tested, although cryptoperidiniopsoids have not been associated with fish kills. 相似文献
16.
The zooplankton of freshwater systems has been recognized as an important energy resource for fish of small body size that,
in turn, provide energy to piscivorous fish consumers higher up the food web. This study evaluates the importance of zooplankton
to the diets of three species of fish living in floodplain waterholes of an Australian dryland river. The species selected
for study represent different trophic categories in waterhole food webs: Ambassis agassizii is a microcarnivore, Leiopotherapon unicolor is an omnivore, and Nematalosa erebi is a detritivore. Dietary differences among size classes of each species were also evaluated to understand possible ontogenetic
shifts in zooplankton consumption. Ambassis agassizii fed primarily on zooplankton (99.9%, made up mostly of 81.6% Calanoida and 17.4% Moinidae), regardless of the size of individual
fish. Leiopotherapon unicolor fed on zooplankton (47%, mostly Daphniidae and Moinidae) and aquatic insects (46.7%). Smaller individuals of Leiopotherapon unicolor (30–49 mm TL—total length) were responsible for 36.1% of the plankton consumed by the species. Nematalosa erebi fed on detritus (84.6%) with zooplankton (Calanoida, Moinidae, and Cyclopoida) contributing only 13.7% of the mean diet.
Smaller individuals (40–69 mm TL) were responsible for 98% of the plankton consumed by Nematalosa erebi, and individuals of 40–49 mm (TL) fed exclusively on zooplankton (53.8% Moinidae and 46.2% Calanoida). Although the three
fish species had different diets, reflecting differences in species-specific and ontogenetic morphological and behavioral
characteristics, zooplankton formed the basis of the diet of all species when young. These results confirm the importance
of zooplankton as a major food resource for three fish species and smaller size classes of these species in floodplain waterholes
of the Macintyre River, Australia.
Guest editors: U. M. Azeiteiro, I. Jenkinson & M. J. Pereira
Plankton Studies 相似文献
17.
W. Thimdee G. Deein N. Nakayama Y. Suzuki K. Matsunaga 《Wetlands Ecology and Management》2008,16(6):463-470
Stable carbon and nitrogen isotope ratios were used to elucidate primary carbon sources and trophic relationships of the fish
and shrimp community in the Klong Ngao mangrove ecosystem, southern Thailand. There were no significant differences in isotopic
compositions of biota between mangrove and offshore sites (Welch–Aspin test). The δ15N values of eight fish species and two shrimp species at both sites were also not significantly different by the test, meaning
that at both sites they feed on the same diets due to the discharge of large quantities of mangrove sediments. The δ15N isotopic enrichment of consumers suggested that there are four trophic levels in the Klong Ngao food web, with at least
two fish species capable of switching feeding strategies and thus altering their apparent trophic positions. Phytoplankton
culture experiments indicated that mangrove-derived sediments could play an important role in stimulating phytoplankton growth
for low turbidity offshore areas, thus providing an alternate food source. The isotopic associations among sources and consumers
indicated that mangroves were the major carbon source supporting aquatic food webs in the Klong Ngao ecosystem. 相似文献
18.
Naoki Agetsuma 《International journal of primatology》1994,15(5):595-609
I investigated the activity budget and diet of Yakushima macaques (Macaca fuscata yakui,)in warm temperate broad- leaved forest of Yakushima, Japan. Both time spent feeding and time spent moving varied considerably
between half- months. However, total time spent in active behaviors— feeding time plus moving time— was stable. The composition
of the diet also showed considerable variation between half- months. The macaques fed mainly on fruits, seeds,mature leaves, fallen seeds, flowers, and young leaves, each of which accounted for more than 30% of feeding time in at least
1 half- month. They also ate insects and fungi, but each of them comprised ≤ 25 and ≤ 8% of feeding time in any half- month,
respectively. Time spent feeding on mature leaves, young leaves, flowers, or fallen seeds is positively correlated with total
time feeding and is negatively correlated with time moving. In contrast, time feeding on fruits, seeds, insects or fungi is
negatively correlated with time feeding and is positively correlated with time moving. Foraging on foods that have a low energy
content, a high density, and a relatively even distribution— mature leaves— or that need much manipulation to be processed—
flowers and fallen seeds— increased feeding time, while foraging on foods for which monkeys must search intensively in the
forest— fruits, seeds, insects, and fungi— led to increased moving time. I examined foraging strategies of Yakushima macaques
in terms of moving costs and the quality of food items. Regarding time feeding on fruits, which have more energy and may need
less manipulation than other foods, as a benefit, and moving time as a cost, they seemed to employ a strategy that balanced
the costs and benefits of foraging. 相似文献
19.
Tamaki Maruhashi 《Primates; journal of primatology》1981,22(1):1-14
Activity patterns of Japanese monkeys (Macaca fuscata) were observed for 240 hr from August to December 1976 on the western slope of Mt. Kuniwari, Yakushima Island, Japan. Activity
patterns and the time budget of a habituated wild troop which consisted of 47 animals in August 1976, were studied quantitatively
by using the scan-sampling method at 15-min intervals. Six thousand seven hundred and six animals were recorded in 959 scans
during the study period and the mean number of animals seen per scan was 7.0. The time budget established for different categories
of activity was as follows: inactive—20.9%; moving—22.8%; feeding—23.5%; social grooming—27.9%; self-grooming—1.2%; and other
activities—3.7%. Adult males spent less time in feeding and more time in resting or being inactive than females or juveniles.
The daily activity patterns were highly variable with respect to time. Intraspecific variations were examined between troops
in several regions of Japan and it was noted that the percentages of time devoted to feeding were similar in all areas.
Inter-species variations in the activity budgets of several species of primates were also examined. The percentage of time
spent in social grooming by Japanese monkeys is exceptionally high compared to that recorded in other species. 相似文献