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1.
V. S. Ivlev 《Bulletin of mathematical biology》1965,27(1):215-222
The survival rate of fishes in their earlier stages of development and the influencing factors present one of the most fundamental
problems of fish population dynamics. After I. Hjort's (Cons. L.'explor. Ner.,20, 3–228, 1914) work, there have been many investigators in this field and there is no doubt about the very important role
of ova and larvae mortality in the fate of a given fish generation.
Less clear are the ideas concerning factors determining the high mortality of fishes in their earlier stages of development;
especially the factor of food supply of larvae during the period of transition to exogenic nutrition. The value of this factor
has been estimated differently from different points of view. For example, R. J. H. Beverton and S. J. Holt (On the Dynamics of Exploited Fish Population, 1957) have given to the food supply factor its deserved importance. On the other hand, T. V. Dekhnik (Trudy Sevastopolskoi Biologicheskoi Stantsii,13, 216–244, 1960;Ibid.,14, 222–243, 1961) has proved in her investigations that at least for pelagic larvae of Black Sea fishes there is an excessive
amount of food, and that therefore food cannot play an important role in larva survival.
Not wanting to stop to review the literature of the problem (see Dekhnik,Trudy Sevastopolskoi Biologicheskoi Stantsii,13, 216–244, 1960), we will only remark that the problem as a whole needs further investigation. Not only new data are needed,
but also methods for following up analysis have to be worked out. 相似文献
2.
Seasonal and interannual variation of subtidal fish assemblages in Wakasa Bay with reference to the warming trend in the Sea of Japan 总被引:1,自引:0,他引:1
Reiji Masuda 《Environmental Biology of Fishes》2008,82(4):387-399
A bi-monthly underwater visual census was conducted in the subtidal habitat of Nagahama, Wakasa Bay, Sea of Japan, over 5 years
from January 2002 to December 2006. A total of 83 fish species and 63,328 individuals were recorded over 120 1-h visual censuses
composed of three 2 × 200 m transects. The number of both total individuals (abundance) and species (richness) were strongly
correlated with the bottom-water temperature. Species richness was greatest in summer (July–September), with 10–20 species
per 400 m2, when the sea-bottom temperature was highest (24–28°C), and lowest in winter (January–March), with 1–8 species per 400 m2, when the temperature was lowest (10–12°C). Five species, i.e., rockfish, Sebastes inermis, wrasse, Pseudolabrus sieboldi, two species of goby, Acentrogobius pflaumii and Tridentiger trigonocephalus, and pygmy filefish, Rudarius ercodes, were frequently observed and present in more than 200 of the total of 360 total transects. While the presence of most fish
species was dependent on water temperature, some species were independent of water temperature, including anchovy, Engraulis japonicus, S. inermis, wasp fish, Hypodytes rubripinnis, A. pflaumii and pufferfish, Takifugu poecilonotus. Jack mackerel, Trachurus japonicus, was the most abundant fish, being most typically seen from spring through autumn, with a total of 21,850 individuals observed
over the whole census period. Some species showed strong annual fluctuations in abundance. The interannual stability in fish
abundance and species richness was probably because the fish assemblage was composed of a sufficiently large number of species,
but with the number of each species fluctuating over time. A comparison of the present survey to one in 1970–72 revealed that
over the last 30 years southern fish species have significantly increased whereas those indigenous to northern waters have
decreased.
相似文献
Reiji MasudaEmail: |
3.
Phosphorus (P) to chlorophyll ratios and zooplankton–phytoplankton (Z:P) biomass ratios were assessed in 400 temperate lakes
over a gradient of phosphorus (P) and with different fish communities. Most of the lakes in this survey were oligotrophic,
with a median total P of 7.3 μg P L−1. Thus, the survey provided information on food web effects during the early phase of eutrophication. There was no tendency
toward a reduced yield of autotrophs per unit of P over the gradient covered in this survey. The zooplankton yield per unit
of P or chlorophyll a decreased slightly with increased nutrient concentrations, and Z:P biomass ratios decreased with fish community classes,
reflecting increased fish predation pressure. However, the variability in biomass ratios within a given range of P and fish
class was some 100 times higher than the difference over the gradients. This finding suggests that lake-specific properties,
community composition, and food quality are by far the most important determinants of biomass ratios and probably also trophic
efficiency in lakes; it further suggests that these factors are superimposed on the general effect of eutrophication, at least
up to 30 μg P L−1. 相似文献
4.
In order to examine the distribution, abundance, and food habits of the snailfish,Liparis tanakai, in the Suo Sea, western Seto Inland Sea of Japan, experimental fishing surveys were made using trawl nets on the night (1930–0340
h) of 26 May and 2 and 3 June, 1986. The study area was subdivided into 18 areas, each sampled by one trawl tow of 35 min
duration. A total of 190 fish was collected during the surveys, and most fish (78.9%) were obtained from muddy substrata ranging
in depth from 30 to 40 m at the middle area of the Suo Sea. The total length of the fish in the samples ranged from 72 to
273 mm. The overall length-frequency distribution formed a unimodal curve, the mode occurring at the class of 100–130 mm in
total length. Of 151 fish examined, 146 (96.7%) had stomachs full of food, including a variety of small crustaceans and fish.
Shrimps, especiallyCrangon affinis, ranked highest in importance in the diet ofL. tanakai. These biological data are compared with those of conspecifics from Sendai Bay, northern Honshu of Japan. 相似文献
5.
J. Bonde 《BioControl》1989,34(2):275-287
Amblyseius barkeri (Hughes) fed onThrips tabaci (Lind.) at 25°C showed an average duration of 2.2, 0.8 and 3.2 days for the egg, larval and nymphal stages, with mortalities
at 1.0, 1.0 and 3.1%, respectively. Females represented 63% of the population and required multiple matings for optimal fertility.
The oviposition period was 20.3 days and the average oviposition rate 2.3 eggs per day. The intrinsic rate of increase was
0.22 per day. The expected life span was 29.6 days for ♀♀ and 27.4 days for ♂♂.A. barkeri ♂♂ and ♀♀ both consumed 3.3 nymphs of thrips per day (mean value for the feeding stages). The larva does not take up food.
In the absence of thripsA. barkeri was able to consume two-spotted spider mites,Tetranychus urticae (Koch), and their eggs, adult broad mites,Polyphagotarsonemus latus (Banks), and pollen of various plants. Cannibalism was observed when food was lacking. Certain morphological features, egglaying,
mating and predatory behaviour are described.
相似文献
6.
Alexandra S. Grutter 《Oecologia》1997,111(1):137-143
The ecological significance of cleaner fish on coral reefs was investigated. I removed all cleaner fish, Labroides dimidiatus, from eight small reefs, measured the subsequent effect on the abundance and species composition of all reef fish after 3
and 6 months, and compared it with eight control reefs with cleaner fish. The removal of cleaner fish had no detectable effect
on the total abundance of fish on reefs and the total number of fish species at both times. Multivariate analysis by non-metric
multidimensional scaling and ANOSIM pairwise tests based on 191 fish species revealed no effect of cleaners on the community
structure of fish. Similar results were obtained using principal components analysis on subsets of the data using the 33 most
common fish species and the 15 most abundant species (≥5 individuals per reef ) with both log10 (x + 1) transformed data and with fish numbers standardized for abundance. This study demonstrates that the removal of cleaner
fish for 6 months did not result in fish suffering increased mortality nor in fish leaving reefs to seek cleaning elsewhere.
Received: 28 October 1996 / Accepted: 7 February 1997 相似文献
7.
D. Piepenburg N. V. Chernova C. F. von Dorrien J. Gutt A. V. Neyelov E. Rachor L. Saldanha M. K. Schmid 《Polar Biology》1996,16(6):431-446
Composition and distribution of megabenthic communities around Svalbard were investigated in June/July 1991 with 20 Agassiz
trawl and 5 bottom trawl hauls in depths between 100 and 2100 m. About 370 species, ranging from sponges to fish, were identified
in the catches. Species numbers per station ranged from 21 to 86. Brittle stars, such as Ophiacantha bidentata, Ophiura sarsi and Ophiocten sericeum, were most important in terms of constancy and relative abundance in the catches. Other prominent faunal elements were eunephthyid
alcyonarians, bivalves, shrimps, sea stars and fish (Gadidae, Zoarcidae, Cottidae). Multivariate analyses of the species and
environmental data sets showed that the spatial distribution of the megabenthos was characterized by a pronounced depth zonation:
abyssal, bathyal, off-shore shelf and fjordic communities were discriminated. However, a gradient in sediment properties,
especially the organic carbon content, seemed to superimpose on the bathymetric pattern. Both main factors are interpreted
as proxies of the average food availability, which is, hence, suggested to have the strongest influence in structuring megabenthic
communities off Svalbard.
Received: 28 April 1995/Accepted: 18 November 1995 相似文献
8.
9.
Daphnia hyalina × galeata (Dhg) and D. pulicaria (Dp) are ready to pay greater costs in terms of predation risk avoidance at high rather than at low food levels. Such costs are
easier to assess in Daphnia than in large long-lived and difficult-to-handle herbivores, since they can be precisely determined in a few-day experiment
as the reduced growth (P=A−R) resulting from diminished assimilation (A) and/or increased respiration (R). In experiments with Daphnia grown for six days from the neonate to the first clutch of eggs, which were given different levels of algal food (Scenedesmus at concentrations from 0.05 to 1.60 mg C l−1), individual growth was lower in the presence of fish kairomone (chemical information on fish predation; present at a concentration
that induces antipredator defensive behavior and life histories) than in the absence of kairomone (control). The difference
from the control was negligible at the lowest food levels, and gradually increased with increasing food concentration. At
a food concentration of 1.6 mg C l−1, growth was reduced by 9–32 and 0–8% in Dhg and Dp, respectively, compared to the controls. A similar reduction was observed in the body length of six-day-old animals (Dhg 6–19%, Dp 0–14%), but not in the first clutch reproductive effort (clutch volume). Daphnia had a greater number of eggs per clutch in the presence of the kairomone, but smaller eggs, so that the total volume of eggs
in a clutch was the same with and without kairomone. The amplification of the effect of the kairomone due to high food levels
was weaker in Dp, a species that rarely coexists with planktivorous fish in natural habitats. 相似文献
10.
The cardinal tetra (Paracheirodon axelrodi) is the most abundant species of the Brazilian ornamental fish trade, constituting more than 80% of the ornamental fish collected
in the middle Negro River basin. Stable isotope analyses were used to identify the autotrophic carbon sources and trophic
position for the cardinal in relation to the plant groups at the base of its foodchain. Filamentous algae, tree and plant
leaves and cardinals were collected in stream habitats, flooded forest and interfluvial swamps (campos) during peak flood,
falling water and low water periods. δ15N values of the cardinal in relation to the plants at the base of the food chain indicated a trophic position of omnivore.
Values of δ13C for the plants ranged from −43.1 to −26.4‰, with averages of −37.6, −30.4, and −29.4‰ for filamentous algae, flooded forest
leaves, and campo leaves, respectively. The δ13C values for the cardinal ranged from −35.0 to −27.9‰, with an average of −31.4‰. Relative contributions of plants to fish
carbon were estimated in a two end-member mixing model which determined that the leaves (flooded forest and campo leaves combined)
and filamentous algae had average relative contributions to cardinal carbon of 71% and 29%, respectively. However, seasonal
variation in the relative contributions was encountered throughout the hydrological cycle. The cardinals least enriched in
13C were encountered in November during the falling water period, indicating that they had perhaps recently migrated down from
interfluvial campos where filamentous algae production is significant. Considering that algal production has been reported
to be less than 1% of total primary production in the Negro River, these results could suggest some evidence of selective
herbivory in the cardinal’s food chain.
Handling editor: J. M. Melack 相似文献
11.
We extend the game theoretic model of kleptoparasitism introduced by Broom and Ruxton (1998, Behav. Ecol.
9, 397–403) in two ways: we allow for asymmetric contests, where the probability α of the challenger winning can take any value from 0 to 1; and we allow the handler to choose not to resist the challenge,
but to immediately concede and relinquish its food to the challenger. We find, in general, three possible evolutionarily stable
strategies—challenge-and-resist (Hawk), challenge-but-do-not-resist (Marauder) and do-not-challenge-but-resist (Retaliator).
When α = 1/2, we find that Hawk and Marauder are the only ESS’s, in contrast to the result of the original model; we also find an
overlap region, in parameter space, where two different ESS’s are possible, depending on initial conditions. For general α, we see that all three ESS are possible, depending on different values of the environmental parameters; however, as the average
time of a contest over food becomes long, then the Marauder strategy becomes more and more prevalent. The model makes a potentially
significant prediction about animal behaviour in the area of kleptoparasitism, that a searcher, when it meets a handler, will
only decline to attack that handler when α < 1/2 i.e.when the defender is more likely to win. One possible converse of this statement, that a handler whose probability
of success is greater than 1/2 should always resist a challenge, is not true. 相似文献
12.
Md. Shahidul Islam Mohammed Mokhlesur Rahman Govinda Chandra Halder Masaru Tanaka 《Aquatic Ecology》2006,40(2):263-272
The fish assemblage of a traditional Kata fishery and the stomach contents of Wallago attu were studied over a period of one year from a large floodplain system in Bangladesh. A total of 19 species of fish and 2 species of shrimp were recorded. W. attu (9.7–17.8%), Mystus vittatus (6.0–11.3%), M. aor (5.0–12.1%), Amblypharyngodon mola (4.4–9.3%) and Mastacembelus armatus (3.5–10.5%) dominated the catch. W.␣attu occupied the top position in abundance throughout the year, followed by M. vittatus and M. aor. Bagridae, Siluridae and Cyprinidae were three major families that contributed respectively 21.0, 17.4 and 16.1% of the total catch. Considerable seasonality was observed in the abundance of different fishes. A total of 14 different prey items were recorded, belonging to three major groups (fish, prawn and plant matters). The fish fed on at least eight species of small fishes (A. mola, M. vittatus, M. cavasius, Puntius stigma, P. ticto, Puntius sp., Glossogobius guris, and Heteropneustes fossilis) and some other unidentified small fishes. Other major prey items were small prawn, fish and prawn remains, and macroalgae. A. mola was the most important food item, contributing 23.7% of the total amount of diet by weight and 19.9% by frequency of occurrence. A. mola was followed by unidentified small prawn (13.7%), M. vittatus (13.1%), and unidentified small fishes (8.8%) by weight and by unidentified small fishes (15.9%), fish remains (12.5%), and M.␣vittatus (12.3%) by occurrence. Of the major diet categories, fish contributed 74.3% of the total diet by weight and 80.9% by occurrence, prawn contributed 18.5% by weight and 11.0% by occurrence and plants contributed 7.2% by weight and 8.1% by occurrence. A. mola and small shrimps were positively selected by W. attu. We concluded that W. attu is a piscivorous predator with potential impacts on prey fish communities; we also hypothesized that a specialized food-web based on the Kata fishery exists in and around the Katas which is of particular ecological significance. 相似文献
13.
Anatol Rapoport 《Bulletin of mathematical biology》1956,18(4):317-321
A learning curve derived by H. D. Landahl (Bull. Math. Biophysics,3, 71–77, 1941) from postulated neurological structures is shown to be derivable from simplified assumptions by introducing
the information measure of the uncertainty of response. The possible significance of this approach to learning theory is discussed. 相似文献
14.
The dietary composition of juvenile Trematomus newnesi, trawled at Potter Cove, South Shetland Islands, in the summers 2004–2005 and 2005–2006 was analysed using frequency of occurrence
(F%) and dietary coefficient Q (%) methods. The samples consisted exclusively of immature specimens in the range 4–15.4 cm (total length) and are complementary
to those of larger fish from the same site, including adults, which were analysed in previous work. Benthic-demersal organisms
such as gammaridean amphipods and harpacticoid copepods were the main (coefficient Q) and most frequent (F%) prey. The importance of the smaller and larger main prey diminished and increased, respectively, during ontogeny. Pelagic
krill, being negligible in the diet of the small and medium size fish categories, became secondary food, but only for fish
larger than 12 cm. Other taxonomic groups occurred scarcely and constituted occasional food. They were mostly benthic, such
as gastropods, bivalves, isopods, cumaceans, and algae, with the exception of an insignificant number of pelagic ostracods
and calanoid copepods. Unlike the more pelagic/planktivorous mode of life known for late juvenile-adult stages of T. newnesi, including cryopelagy, present results indicate that early juvenile fish remain sheltered among macroalgae beds preying on
the associated community of demersal-benthic organisms. 相似文献
15.
Influence of body weight/age on the food intake,growth and conversion efficiency of Gambusia affinis
On a restricted food supply of Tubifex tubifex (2h/day) the fish consumed only 69.5 mg dry food/g live fish/day and grew only to 25.6 mg live body weight by the 30th day of it's age, while those fed ad libitum consumed 94.7 mg/g/day and attained a body weight of 125.9 mg live weight by the 30th day. Conversion efficiency (K1) averaged to 8.3% in the former and 14.1% in the latter series, throughout the 30 day experimental period.Feeding rate of the test series fed individually and at ad libitum, decreased from 780 mg dry food/g dry fish/day for a fish weighing 4 mg dry weight to 180 mg/g/ day for one weighing 41 mg, exhibiting a log-log relationship to the body weight (Y = 2.20140–0.5639 X). Growth rate also decreased as a log-log function with increasing body weight (Y = 1.2309–0.4384 X). 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.
E. V. Levina D. L. Aminin S. N. Kovalchuk V. B. Kozhemyako S. A. Dyshlovoi A. I. Kalinovskii P. S. Dmitrenok 《Russian Journal of Bioorganic Chemistry》2010,36(2):233-239
Four polyhydroxylated steroids, new (20R)-5α-cholestan-3β,6α,8,15α,24,26-hexaol (I) and known (20R,25S)-5α-cholestan-3β,6α,8,15β,16β,26-hexaol, (20R,25S)-5α-cholestan-3β,6α,15β,16β,26-pentaol, and marthasterone sulfate were isolated from the Solaster endeca starfish inhabiting the Sea of Okhotsk and characterized. Steroid (I) contains a 24,26-dihydroxylated side chain, which is unique for starfish polyols. The isolated steroids and related metabolites
from two starfish species of the Evasterias genus (in total, 15 compounds) were weakly cytotoxic in a human HeLa cell culture and some of them were inhibitors of non-specific
esterase from mouse Ehrlich carcinoma. The effects of these compounds on the p53 protein activity were studied in a yeast
two-hybrid test system and both inhibitors and stimulators of this activity were found among them. 相似文献
18.
This study examined mercury levels in northern pike (Esox lucius) from the Twin Valley Reservoir in southern Alberta, 2 years after construction in 2003. The hypothesis was tested that mercury
concentrations in pike from the reservoir are significantly higher than in pike from the nearby Oldman River. Mercury concentrations
in muscle tissue (0.37–1.54 ppm) generally exceeded the consumption guideline of 0.5 ppm total mercury (THg), and were significantly
higher (3.5-fold) than northern pike mercury concentrations in the Oldman River. In addition, these levels exceeded (up to
2-fold) previously published data from other reservoirs of the northern hemisphere. Gill-netting followed by stomach contents
and stable isotope analysis revealed a very simple food web. No zooplanktivorous fish species were present, and the benthic
fish community contained only few white sucker (Catostomus commersoni). Thus, the reservoir almost completely lacked forage fish, and the pike fed primarily on amphipods (Gammarus lacustris and Hyalella azteca), whose average mercury concentrations were 0.21 ppm. An observed low growth trajectory of northern pike in this reservoir
may reflect low growth efficiency as a result of their invertebrate diet. 相似文献
19.
Alan K. Whitfield Ricky H. Taylor Caroline Fox Digby P. Cyrus 《Reviews in Fish Biology and Fisheries》2006,16(1):1-20
The recorded salinity ranges of freshwater, estuarine and marine fish species in Lake St Lucia, a Ramsar and World Heritage Site, are documented. The freshwater group is most diverse and abundant under oligohaline conditions, although the Mozambique tilapia (Oreochromis mossambicus) was common under all salinity regimes. Estuary resident species also favoured oligohaline conditions but, in contrast to the freshwater taxa, were well represented in salinities up to 40 ‰. The marine group was most diverse and abundant within the salinity range 10–40 ‰, but a large number of species could also be found in salinities up to 70 ‰. Very few fish species were able to tolerate salinities between 70 ‰ and 110 ‰, with only O. mossambicus surviving for extended periods in salinities above 110 ‰. All the aquatic macrophytes and most of the zoobenthos within the lake appear to die out within the salinity range of 50–60 ‰, thus creating additional stress to those fish present under such conditions. The food resources least affected by extreme hypersalinity are the microphytobenthos and detritus food chains, with detritivorous fishes being dominant when the lake is in this state. Mass mortalities of fishes in Lake St Lucia have been recorded under both low (<5 ‰) and high salinity (>70 ‰) conditions. The fish kills are often triggered by exceptionally low or high water temperatures which affect the osmoregulatory abilities of these species. Hypersaline conditions and fish mortalities under the most recent closed estuary mouth conditions (2002–2005) are reviewed. If the surface area of St Lucia (35,000 ha) is compared to the total surface area of all South African estuaries (approximately 70,000 ha), then the possibility exists that the loss of the Lake St Lucia nursery area for estuary-associated marine fish species over the past few years may cause significant short-term declines in the future abundance of these taxa on both a local and regional scale. 相似文献
20.
C. R. Joiris 《Polar Biology》1996,16(6):423-429
At-sea distribution of seabirds and marine mammals was quantitatively determined during the Arctic EPOS cruise of RV Polarstern,
from 21 June till 28 July 1991, during 377 half-an-hour counts. Data were expressed as numbers per count and as density, and
daily food intake was calculated using allometric equations from literature. Mean densities for the whole expedition were
29 seabirds per km2 (mainly little auk,Alle alle: 8.7, kittiwake,Rissa tridactyla: 8.2, Brünnich’s guillemot,Uria lomvia: 6.5 and fulmar,Fulmarus glacialis: 3.4), 0.06 pinnipeds, 0.01 cetaceans and 0.002 polar bears. Total food intake by seabirds and marine mammals was 3.9 kg fresh
weight/km2 per day, with extreme values of 6.6 in the northern west-to-east transect and 2.5 in the Storfjorden. The major ecological
influence were fish eaters (1.7), and more especially Brünnich’s guillemot (1.2). Geographic differences were also detected:
food intake by Brünnich’s guillemot represented 62% of total intake in Storfjorden, and by the kittiwake, 45% in the first
eastern transect. The first and last transects in the western Barents Sea are described and discussed in more detail. Within
different sectors, high concentrations of seabirds were noted, corresponding to hydrological features such as fronts between
Atlantic and polar waters, as well as ice edges. Values of seabirds’ density and food intake are higher than in the Greenland
Sea, even than at the biologically very active ice edge there. Figures for pinnipeds and cetaceans are similar; numbers of
polar bears were higher around Spitsbergen.
The data presented were collected during the European “Polarstern” Study (Arctic EPOS) sponsored by the European Science Foundation 相似文献