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1.
Seasonal variation in the relationship between cellular immune response and badge size in male house sparrows (Passer domesticus) 总被引:7,自引:2,他引:5
Guillermo Gonzalez Gabriele Sorci Florentino de Lope 《Behavioral ecology and sociobiology》1999,46(2):117-122
The immunocompetence handicap hypothesis postulates that secondary sexual traits are honest signals of male quality because
steroid hormones (such as corticosteroids and sex steroids), which are supposed to favor the development of secondary sexual
traits, may also have immunosuppressive effects. Certain secondary sexual traits are not only used as mate choice signals
but also play a role as badges of status. In the house sparrow (Passer domesticus), males have a bib of black feathers which is used both as a signal of social status in male-male interactions and by females
when choosing a mate. We investigated the relationships between bib size and cellular immune response in male house sparrows
during and outside the reproductive season. Males with large badges were found to have lower levels of immunocompetence, as
assessed using a T-cell-mediated immunity assay, during the reproductive season, as predicted by the immunocompetence handicap
hypothesis. Conversely, in November, the correlation between badge size and cellular immune response was positive, possibly
reflecting the better access to trophic resources of large-badged dominant males in winter flocks.
Received: 24 September 1998 / Received in revised form: 2 February 1999 / Accepted: 14 February 1999 相似文献
2.
Bioluminescence spectra of shallow and deep-sea gelatinous zooplankton: ctenophores, medusae and siphonophores 总被引:3,自引:0,他引:3
We have examined the variability and potential adaptive significance of the wavelengths of light produced by gelatinous zooplankton.
Bioluminescence spectra were measured from 100 species of planktonic cnidarians and ctenophores collected between 1 and 3500 m
depth. Species averages of maximal wavelengths for all groups ranged from 440 to 506 nm. Ctenophores (41 species) had characteristically
longer wavelengths than medusae (34 species), and the wavelengths from siphonophores (25 species) had a bimodal distribution
across species. Four species each produced two different wavelengths of light, and in the siphonophore Abylopsistetragona these differences were associated with specific body regions. Light from deep-dwelling species had significantly shorter
wavelengths than light from shallow species in both ctenophores (p = 0.010) and medusae (p = 0.009). Although light production in these organisms was limited to the blue-green wavelengths, it appears that within
this range, colors are well-adapted to the particular environment which the species inhabit.
Received: 27 April 1998 / Accepted: 27 October 1998 相似文献
3.
T. R. Fisher A. B. Gustafson K. Sellner R. Lacouture L. W. Haas R. L. Wetzel R. Magnien D. Everitt B. Michaels R. Karrh 《Marine Biology》1999,133(4):763-778
We report nutrient addition bioassays at 18 stations in Chesapeake Bay (USA) to assess resources limiting phytoplankton growth.
Data were pooled from several sampling programs conducted from 1989 to 1994. Spatially, light and P limitation declined from
low salinity regions to high salinity regions, as N limitation increased. This spatial pattern was driven primarily by freshwater
inflows with high N/P and seawater inflows with low N/P. Seasonally, there was a marked progression of winter light limitation,
spring P limitation, and summer N limitation at mesohaline and polyhaline stations. The seasonal pattern appeared to be caused
by temperature, mixing, river discharge, and sediment P fluxes. At high salinity stations, we also observed winter N limitation
(caused by DIN depletion prior to spring nitrate delivery), and at lower salinity stations there was fall P limitation (caused
by reaeration of bottom sediments). At tidal fresh stations, turbidity and nutrient concentrations resulted in continuous
light limitation, except at some stations in summer. Interannual decreases in light limitation and increases in N and P limitation
appear to represent improvements in water quality.
Received: 31 October 1997 / Accepted: 18 December 1998 相似文献
4.
Vertical distribution and population structure of Neocalanus cristatus were investigated at Site H in the Oyashio region from September 1996 through October 1997 to evaluate their life cycle mode.
Additional temporary samplings were also made at several stations covering the entire subarctic Pacific, Okhotsk Sea and Japan
Sea, as a basis for regional comparison of life cycles of this species. At Site H, N. cristatus spawned throughout the year below 500 m depth, with a peak from October to December. The resulting eggs and nauplii floated/migrated
upward, and formed an abundance peak of Copepodite Stage 1 (C1) in the surface layer in February. In the surface layer, the
C1 developed and reached C5 by early June through a phytoplankton bloom which occurred in mid-March to end of June. The C5
migrated to deeper layers in July and August, where they molted to adults. Apparently, the developmental time from C5 to adults
was highly variable (>1 month), and some might overwinter. The life cycle of N. cristatus appeared to be annual for the major portion of the population. Taking into account sampling season, temporal changes in vertical
distribution and population structure data collected from regions other than Site H, there was a close correlation in the
timing of the life cycle over the entire subarctic Pacific, but the reproduction season (April to June) was observed to be
different in the Okhotsk and Japan Sea populations. Regional comparison of prosome length of C5 individuals, including those
in the Bering Sea, indicated significantly larger sizes of specimens from the Japan Sea and Okhotsk Sea, as compared with
those from the entire subarctic Pacific. Possible causes for regional variability in life cycle patterns and body sizes are
discussed.
Received: 18 December 1998 / Accepted: 19 April 1999 相似文献
5.
Changes in male guppy courting distance in response to a fluctuating light environment 总被引:1,自引:0,他引:1
In the guppy (Poecilia reticulata), effective courting by a male requires visual contact with the female. Therefore, environmental light intensity may affect
male display behavior, particularly initial courtship distance. We found that male guppies courted at exact and predictable
distances from the female given a particular light level, both in field and laboratory studies. In lower light levels (<0.1 μmol m−2 s−1), for example at dawn, dusk, or under heavy canopy, males court females at closer and less variable distances (<3 cm). At
higher light levels, which occur during most of the day and with less canopy cover, males often court from twice or three
times further out. Light levels over guppy streams change over relatively short time periods and ranges, correlating with
variation in courtship distances. Laboratory manipulations of irradiance confirmed that courtship distance depends on illumination.
Hence, courtship distances may be set by the effect of lighting on signal efficiency, minimization of energy or time expenditures,
or predation risk.
Received: 16 December 1997 / Accepted after revision: 8 August 1998 相似文献
6.
E. A. Widder S. Johnsen S. A. Bernstein J. F. Case D. J. Neilson 《Marine Biology》1999,134(3):429-437
To learn how organisms apportion space in the open ocean, biological oceanographers have sought to improve temporal and spatial
resolution of ocean sampling systems. Their objectives are to simultaneously measure physical, chemical and biological structure
in the water column in order to find significant correlations that may reveal underlying processes. Here we report one such
correlation between intense peaks of bioluminescence and density discontinuities in the water column. Intensified video recordings
made in these bioluminescent “hot spots” were analyzed with a computer image-recognition program that identifies organisms
based on the temporal and spatial characteristics of their luminescent displays. Based on this analysis, the source of the
“hot spots” was found to be very thin layers (0.5 m) of the bioluminescent copepod Metridia lucens present at from 5 to 100 times average background concentrations. Given the recent discovery that the vertical distribution
of marine snow is also strongly correlated with density discontinuities in the water column, we suggest that this finding
may provide a possible explanation for the disparity between estimated energy requirements of marine copepods and measurements
of average in situ food concentrations. The energy costs associated with locating food-rich micro-patches is greatly reduced
if those patches are spread out into very thin layers, because the search strategy can be reduced from three dimensions to
one.
Received: 28 December 1998 / Accepted: 12 April 1999 相似文献
7.
Using a biopsy dart system, samples of skin tissue were collected from southern right whales (Eubalaena australis) in 1995 on two wintering grounds, southwest Australia (n = 20) and the Auckland Islands of New Zealand (n = 20); and on offshore feeding grounds at Latitudes 40 to 43°, south of Western Australia (n = 5). A variable section of the mitochondrial DNA control-region (289 nucleotides) was amplified and sequenced from these
45 individuals (21 males, 20 females and 4 of unknown sex), distinguishing a total of seven unique sequences (i.e. mtDNA haplotypes).
Two haplotypes were found on both wintering grounds (including a common type representing 45% of each sample), and five types
were unique to only one wintering ground. An analysis of variance adapted for molecular information revealed significant genetic
differentiation between the two wintering grounds (p = 0.017). The feeding-ground sample was too small for statistical comparison with the wintering grounds, but included two
haplotypes found only in the Auckland Islands as well as the common haplotype found on both wintering grounds. The nucleotide
diversity and differentiation of mtDNA among the right whales was similar to that among humpback whales (Megaptera novaeangliae) from the same regions (Baker et al. 1998), but haplotype diversity was significantly reduced, perhaps as a result of more
intensive hunting during the last century and continued illegal hunting during this century.
Received: 16 March 1998 / Accepted: 18 December 1998 相似文献
8.
We manipulated availability of food and nesting sites in one population of the forest ant Myrmica punctiventris. The manipulations produced significant changes in relatedness structure, reproductive allocation, and response to hierarchical
selection. Food availability appeared to have a consistently stronger influence on these aspects of social organization than
did availability of nesting sites. We interpret our experimental results in light of observed differences between populations,
and discuss implications for kin selection dynamics.
Received: 30 July 1998 / Accepted after revision: 31 October 1998 相似文献
9.
The ability of endosymbioses between anthozoans and dinoflagellate algae (zooxanthellae) to retain excretory nitrogen and
take up ammonium from seawater has been well documented. However, the quantitative importance of these processes to the nitrogen
budget of such symbioses is poorly understood. When starved symbiotic Anemonia viridis were incubated in a flow-through system in seawater supplemented with 20 μM ammonium for 91 d under a light regime of 12 h light at 150 μmol photons m−2 s−1 and 12 h darkness, they showed a mean net growth of 0.197% of their initial weight per day. Control anemones in unsupplemented
seawater with an ammonium concentration of <1 μM lost weight by a mean of 0.263% of their initial weight per day. Attempts to construct a nitrogen budget showed that, over
a 14 d period, ≃40% of the ammonium taken up could be accounted for by growth of zooxanthellae. It was assumed that the remainder
was translocated from zooxanthellae to host. However, since the budget does not balance, only 60% of the growth of host tissue
was accounted for by this translocation. The value for host excretory nitrogen which was recycled to the symbionts equalled
that taken in by ammonium uptake from the supplemented seawater, indicating the importance of nitrogen retention to the symbiotic
association.
Received: 23 December 1997 / Accepted: 12 September 1998 相似文献
10.
Importance of cysts in the population dynamics of the red tide flagellate Heterosigma akashiwo (Raphidophyceae) 总被引:7,自引:0,他引:7
To elucidate roles of cysts in occurrences of Heterosigma akashiwo blooms, cyst dynamics were studied in northern Hiroshima Bay, the Seto Inland Sea of Japan, where H. akashiwo regularly forms red tide in June. Monthly measurements of seasonal changes in the densities of vegetative cells of H. akashiwo and their germinable cysts in surface sediments (top 1-cm layer) were made for 2 years at three stations. Vegetative cells
of H. akashiwo could be detected from April through December throughout the water column, and the existence of vegetative cells was confirmed
in surface waters even in winter after incubation of sampled seawater in culture medium. Germinable cysts, enumerated by the
extinction dilution method, existed in sediments in all seasons, even before and after the seasonal bloom. The effects of
incubation temperature on the germination of natural cysts of H. akashiwo in sediments were examined. Germination was not observed at 5 °C, was low at 10 °C, while it increased at 15 °C, and maintained
a high level to 25 °C. The bottom water temperature reached 15 °C (suitable for the germination of cysts) and the surface
about 18 °C or more (suitable for the growth of vegetative cells) 2 to 3 weeks before the blooms. The dark survival of H. akashiwo cysts was tested, and it was found that the cysts were viable for at least 650 d at 11 °C, and for 165 d at 25 °C, indicating
a significant role of cysts in the survival during winter and summer seasons. The cysts presumably also play an important
role in seeding primary populations into water columns when the bottom water reaches a suitable temperature (around 15 °C);
thereafter the populations develop with great annual regularity to bloom in June. These results suggest that initiation of
H. akashiwo red tides in the Seto Inland Sea could be triggered by bottom water temperature.
Received: 3 July 1998 / Accepted: 12 January 1999 相似文献
11.
The mode of reproduction in Pocillopora verrucosa Ellis and Solander, 1786 varies between geographically isolated regions. This scleractinian coral is common along the KwaZulu-Natal
coast, and its reproductive mode and period of reproduction were assessed using histological preparations. The study was undertaken
from 1992 to 1994 and showed that P. verrucosa is a simultaneous hermaphrodite and broadcast spawner in KwaZulu-Natal. Gametogenesis occurs from October to January, with
the gametes maturing simultaneously so that spawning can be synchronised at new moon in January (mid-summer). Zooxanthellae
are present in the mature oocytes.
Received: 10 September 1997 / Accepted: 6 July 1998 相似文献
12.
Kevin R. Foster Perttu Seppä Francis L. W. Ratnieks Peter A. Thorén 《Behavioral ecology and sociobiology》1999,46(4):252-257
Queen mating frequency was studied in the European hornet, Vespa crabro, by analyzing four DNA microsatellite loci in 20 workers from each of 14 nests. Queens were found to be predominantly singly
mated (9/14), although double (4/14) and triple mating (1/14) also occurred. For most multiply mated queens, paternity was
significantly biased with the majority male fathering on average 80% of the female offspring. The population-wide effective
mating frequency was therefore low (1.11), and sister-sister relatedness high (0.701 ± 0.023 SE). Low effective mating frequency
in Vespa, in combination with data from other vespines, suggests that high paternity frequency is derived in the group. Some problems
with the non-detection of fathers, where the queen was not sampled or shared alleles with males, are analyzed.
Received: 16 November 1998 / Received in revised form: 29 March 1999 / Accepted: 12 April 1999 相似文献
13.
Karyotypic characterization of the great sturgeon, Huso huso, by multiple staining techniques and fluorescent in situ hybridization 总被引:1,自引:0,他引:1
F. Fontana J. Tagliavini L. Congiu M. Lanfredi M. Chicca C. Laurente R. Rossi 《Marine Biology》1998,132(3):495-501
A karyotype analysis by several staining techniques was carried out on the great sturgeon, Huso huso (Linnaeus, 1758). The karyotype (2n = 118 ± 2) was composed of 42 pairs of meta-/submetacentric chromosomes and 17 pairs of acrocentrics/microchromosomes. Constitutive
heterochromatin was mainly located at the centromeric regions of the acrocentric chromosomes. The biarmed chromosomes showed
weak C-bands. Fluorescent staining with GC-specific chromomycin A3 showed clearly recognizable fluorescent regions, whereas a more uniform base composition was revealed by the AT-specific
4,6-diamidino-2 phenylindole. After Ag-staining, nucleolar organizer regions could be observed on the short arms of two medium-sized
submetacentrics and on two acrocentrics. Digoxigenated 28S and 5S rDNA probes, prepared from Acipenser naccarii DNA and hybridized to metaphase chromosomes, showed signals on six and two chromosomes, respectively. The telomeric sequence
(TTAGGG)
n
detected by FISH was located at both ends of each chromosome. Results are discussed in relation to karyotype organization
and evolution in sturgeons.
Received: 1 April 1998 / Accepted: 21 July 1998 相似文献
14.
Alasdair I. Houston John M. McNamara Anthony L. Moody 《Behavioral ecology and sociobiology》1998,44(2):143-146
Received: 10 June 1998 / Accepted: 5 July 1998 相似文献
15.
In the eutrophic Veerse Meer lagoon (The Netherlands) large amounts of free-floating thalli from Ulva spp. are present from May to October. In winter however, no algae seem to occur in the lagoon. Sexual reproduction appears
to be negligible, as spore formation and germling growth are observed only sporadically. Results of a field survey showed
that in winter, viable Ulva biomass is present buried in the sediment of the shallow parts of the lagoon. Freezing experiments demonstrated that the
algae are able to survive temperatures of −5 °C for 2 weeks when kept in darkness. In spring, the buried Ulva thalli are liberated out of the sediment to initiate a bloom. A field experiment indicates that bioturbation by the lugworm
Arenicola marina does not stimulate the release of the thalli. Burial and winter survival can explain the rapid increase in Ulva biomass in spring and suggest that the initial spring biomass is one of the major factors determining the maximal biomass
in summer.
Received: 28 October 1997 / Accepted: 20 January 1998 相似文献
16.
Kensuke Nakata 《Behavioral ecology and sociobiology》1998,43(4-5):223-227
To optimally allocate resources between workers, reproductive females, and males, ant workers have to be able to identify
the sex of larvae and raise them differently. The ability of workers to discriminate between the sexes in the brood was tested
in colonies of queenless ponerine ants, Diacamma sp., from Japan. The ratio of male eggs in the egg pile was increased experimentally. This manipulation resulted in a corresponding
increase in the ratio of adult males, suggesting that Diacamma workers do not raise the sexes differently.
Received: 4 November 1997 / Accepted after revision: 14 March 1998 相似文献
17.
European lobsters, Homarus gammarus (L.), were tracked on an artificial reef in Poole Bay on the south coast of England using an electromagnetic telemetry system
which monitored movements between reef units and recorded body movements (pitching and rolling) detected with a tilt switch
incorporated into the transmitting tag. Several environmental variables (water temperature, light, hydrostatic pressure, current
velocity and direction) were recorded simultaneously by the telemetry system, which was self-contained on the seabed. Movements
between units of the artificial reef (excursions outside shelter) were predominantly nocturnal, peaking 1.5 to 3 h after sunset
and returning to low levels shortly before dawn. A marked decline in the number of inter-reef unit movements from late summer
to winter was related to decreasing water temperature rather than to daytime light level, wave height or tidal range. Activity
indicated by the tilt switch was also greater at night, but declined gradually from a peak early in the night to a minimum
at around midday, on average, implying a degree of activity within reef units during daylight. As with movements between reef
units, activity declined seasonally with decreasing water temperature; in addition, the diel pattern of activity disappeared
in winter.
Received: 9 February 1998 / Accepted: 24 July 1998 相似文献
18.
Temporal fluctuations of species composition and abundance of fish juveniles in the National Park Kornati were studied over
12 months from January to December 1992. A total of 40 168 individuals, representing 24 families and 69 species, were collected
using a 50 m long beach seine. The community was dominated numerically by a few species: Atherina hepsetus (45.90%), Sarpa salpa (21.21%), Diplodus vulgaris (10.49%), and Symphodus ocellatus (6.98%), constituting over 84.58% of the total catch. Similarity between patterns in the abundance of the 17 most common
species were examined using correlation matrix-based principal component analysis. Results were compared to the abiotic factors
leading to the conclusion that only a low amount of variation in the abundance field can be explained by temperature, salinity
and dissolved oxygen.
Received: 23 March 1997 / Accepted: 11 April 1997 相似文献
19.
Cysts of the planktonic oligotrich ciliate Strombidium conicum were isolated from sediment samples, collected monthly in Onagawa Bay on the northeastern Pacific coast of Japan, and incubated
under laboratory conditions of 20 °C in light. The excystment ability changed seasonally in a regular manner, which was demonstrated
by alternation of three characteristic seasonal patterns of the cumulative excystment curve, i.e., rapid, delayed and transitional
patterns. While the transitional excystment pattern was characteristic during the period from spring to midsummer, the rapid
pattern occurred during late summer to early winter. The pattern changed again to transitional in midwinter and finally returned
to the delayed pattern in late winter or early spring. We suggest that mud temperature was the most determinative factor of
this seasonality in excystment ability. Such synchronization of annual excystment helps this species to proliferate rapidly
and maintain the vegetative part of the population in the upper water column for a longer period of time where it is subjected
to the dispersion process due to water movement.
Received: 17 September 1996 / Accepted: 18 November 1996 相似文献
20.
Astrid M. Heiling 《Behavioral ecology and sociobiology》1999,46(1):43-49
The nocturnal orb-web spider Larinioides sclopetarius lives near water and frequently builds webs on bridges. In Vienna, Austria, this species is particularly abundant along the
artificially lit handrails of a footbridge. Fewer individuals placed their webs on structurally identical but unlit handrails
of the same footbridge. A census of the potential prey available to the spiders and the actual prey captured in the webs revealed
that insect activity was significantly greater and consequently webs captured significantly more prey in the lit habitat compared
to the unlit habitat. A laboratory experiment showed that adult female spiders actively choose artificially lit sites for
web construction. Furthermore, this behaviour appears to be genetically predetermined rather than learned, as laboratory-reared
individuals which had previously never foraged in artificial light exhibited the same preference. This orb-web spider seems
to have evolved a foraging behaviour that exploits the attraction of insects to artificial lights.
Received: 8 June 1998 / Received in revised form: 18 January 1999 / Accepted: 19 January 1999 相似文献