共查询到20条相似文献,搜索用时 31 毫秒
1.
Gregory W. Stunz Phillip S. Levin Thomas J. Minello 《Environmental Biology of Fishes》2001,61(3):305-313
We examined patterns of habitat selection in wild-caught and hatchery-reared early juvenile red drum, Sciaenops ocellatus, using mesocosm experiments. Experiments were performed in the presence and absence of a pinfish, Lagodon rhomboides. We hypothesized that newly recruited red drum would have distinct patterns of habitat selection, and these patterns could be influenced by the presence of a pinfish predator. Red drum were introduced to replicate mesocosms containing all possible pair-wise comparisons of four different habitat types: marsh Spartina alterniflora, non-vegetated bottom/sand, oyster reef Crassostrea virginica, and seagrass Halodule wrightii. Wild-caught and hatchery-reared red drum showed distinctively different patterns of habitat selection. In general, wild-caught red drum selected structured habitats, while hatchery-reared fish did not show strong selection for any habitat type. When a predator was present, wild-caught red drum either changed habitat selection or showed significant selection for other structured habitats. This predator effect was similar albeit weaker for hatchery-reared red drum, but as in the trials without a predator, overall habitat selection was reduced compared to wild-caught red drum. Our results suggest that in the absence of seagrass, other habitat types such as marshes and oyster reefs may be important recruitment habitat for red drum. Additionally, hatchery-dependent behaviors may need to be assessed in designing stock enhancement programs. 相似文献
2.
James Nelson Jeffrey Chanton Felicia Coleman Christopher Koenig 《Environmental Biology of Fishes》2011,90(3):243-252
To determine the feasibility of using stable isotopes to track diet shifts in wild gag, Mycteroperca microlepis, populations over seasonal timescales, we conducted a repeated measures diet-shift experiment on four adult gag held in the
laboratory. Fish were initially fed a diet of Atlantic mackerel, Scomber scombrus, (mean δ13C = −21.3‰ ± 0.2, n = 20) for a period of 56 days and then shifted to a diet of pinfish, Lagodon rhomboids, (mean δ13C = −16.6‰ ± 0.6, n = 20) for the 256 day experiment. We developed a non-lethal surgical procedure to obtain biopsies of the muscle, liver, and
gonad tissue monthly from the same four fish. We then determined the δ13C value of each tissue by isotope ratio mass spectrometry. For the gonad tissue we used the relationship between C/N and lipid
content to correct for the influence of lipids on δ13C value. We observed a significant shift in the δ13C values of all of the tissues sampled in the study. Carbon turnover rates varied among the three tissues, but the shift in
diet from mackerel to pinfish was clearly traceable through analysis of δ13C values. The turnover rates for muscle tissue were 0.005‰ day−1, and for gonad tissue was 0.009‰ day−1. Although it is generally thought that tissue turnover rates in ectotherms are driven primarily by growth, we found that
metabolic rate can be a major factor driving tissue turnover in adult gag. 相似文献
3.
Interspecific variation in the escape responses of aphids: effect on risk of predation from foliar-foraging and ground-foraging predators 总被引:1,自引:0,他引:1
A series of laboratory experiments was conducted to determine the effect of interspecific differences on prey defensive behavior
on the susceptibility of two aphid species (Acyrthosiphon pisum and A. kondoi) to a ground-foraging predator, Harpalus pennsylvanicus, and a foliar-foraging predator, Coccinella septempunctata. These organisms are representative of a biologically and economically important predator/prey system in alfalfa. The primary
defensive behavior of both aphid species toward C. septempunctata was to “drop” from the plant. Both aphid species were significantly more likely to drop from the plant in the presence of
C. septempunctata. However, when C. septempunctata was present, a significantly lower proportion of A. kondoi individuals dropped (0.42 ± 0.07) compared to A. pisum (0.73 ± 0.08). As a result of their lower propensity to drop from the plant A. kondoi individuals are significantly more likely to be consumed by C. septempunctata. Conversely, the higher propensity of A. pisum individuals to drop increased their susceptibility to ground-foraging predators. When A. pisum was the prey species, ground-foraging predators made a significant contribution to overall aphid suppression and there was
a significant synergistic interaction between ground and foliar-foraging predators. When A. kondoi was the prey there was no interaction between the predator species. As either a cause or consequence of its higher propensity
to drop, A. pisum seems to be more adapted for survival and dispersal off the plant. In comparison to A. kondoi individuals, A. pisum individuals relocate plants more quickly (63 ± 41 s vs. 164 ± 39 s), disperse farther (18 ± 1.7 cm vs. 13 ± 0.66 cm), and
survive longer (37 ± 2.0 h vs. 25 ± 2.0) off the plant. This study demonstrates the importance of prey defensive behavior
in determining the susceptibility of a prey species to a multiple-predator complex.
Received: 24 February 1997 / Accepted:17 December 1997 相似文献
4.
Veronica L. Bura Antoine K. Hnain Justin N. Hick Jayne E. Yack 《Journal of Insect Behavior》2012,25(2):114-126
The tobacco hornworm (Manduca sexta) is a model organism extensively studied for many aspects of its biology, including its anti-predator strategies. We report
on a novel component of this caterpillar’s defence repertoire: sound production. Late instar caterpillars produce discrete
clicking sounds in response to disturbance. Click trains range in duration from 0.3–20.0 s (mean 3.3 ± 4.8 s) and contain
2–41 clicks (mean 7.1 ± 9.5). Sounds are broadband with a dominant frequency of 29.8 ± 4.9 kHz. We investigated the mechanism
of sound production by selectively ablating three identified sets of ridges on the mandibles, and determined that ridges on
the inner face strike the outer and incisor ridges on the opposing mandible to produce multi-component clicks. We tested the
hypothesis that clicks function in defence using simulated attacks with blunt forceps. In single attack trials 77% of larvae
produced sound and this increased to 100% in sequential attacks. Clicks preceded or accompanied regurgitation in 93% of multiple
attack trials, indicating that sound production may function in acoustic aposematism. Sound production is also accompanied
by other behaviours including directed thrashing, head curling, and biting, suggesting that sounds may also function as a
general warning of unprofitability. 相似文献
5.
A central issue in predator–prey interactions is how predator associated chemical cues affect the behaviour and life history of prey. In this study, we investigated how growth and behaviour during ontogeny of a damselfly larva (Coenagrion hastulatum) in high and low food environments was affected by the diet of a predator (Aeshna juncea). We reared larvae in three different predator treatments; no predator, predator feeding on conspecifics and predator feeding on heterospecifics. We found that, independent of food availability, larvae displayed the strongest anti-predator behaviours where predators consumed prey conspecifics. Interestingly, the effect of predator diet on prey activity was only present early in ontogeny, whereas late in ontogeny no difference in prey activity between treatments could be found. In contrast, the significant effect of predator diet on prey spatial distribution was unaffected by time. Larval size was affected by both food availability and predator diet. Larvae reared in the high food treatment grew larger than larvae in the low food treatment. Mean larval size was smallest in the treatment where predators consumed prey conspecifics, intermediate where predators consumed heterospecifics and largest in the treatment without predators. The difference in mean larval size between treatments is probably an effect of reduced larval feeding, due to behavioural responses to chemical cues associated with predator diet. Our study suggests that anti-predator responses can be specific for certain stages in ontogeny. This finding shows the importance of considering where in its ontogeny a study organism is before results are interpreted and generalisations are made. Furthermore, this finding accentuates the importance of long-term studies and may have implications for how results generated by short-term studies can be used. 相似文献
6.
Thomas J. Minello Roger J. Zimmerman 《Journal of experimental marine biology and ecology》1983,72(3):211-231
The effect of artificial Spartina structure on the predation rates of four estuarine fish on juvenile brown shrimp (Penaeus aztecus Ives) was examined under laboratory conditions. Vegetative structure reduced predation rates of pinfish and Atlantic croaker but did not affect predation rates of red drum and speckled trout. Pinfish and Atlantic croaker were inefficient predators, needing several strikes before successfully capturing prey. This inefficiency, necessitating repeated detection of prey organisms, probably contributed to the reduced predation rates by these fish in vegetated treatments. Although pinfish and speckled trout appeared to be strictly visual feeders, Atlantic croaker and red drum could apparently detect and feed upon shrimp through other sensory mechanisms. Differences in the mode of feeding among the fish, however, did not appear to be related to the effect of vegetative structure on predation rates. Over all of the experiments, predation rates on shrimp (50–69 mm) ranged between ≈2 and 13 shrimp·fish?1·day?1, and there was a positive relationship between the number of shrimp eaten and the size of the predator. 相似文献
7.
Dimitris G. Sfakianakis Ioannis Leris Maroudio Kentouri 《Environmental Biology of Fishes》2011,90(4):421-427
It is widely known that water temperature affects the swimming capacity of fish. But the effect of the rearing temperature
on the swimming ability of the fish at later stages, has not had similar attention. In this study, four populations of zebrafish,
were reared in different water temperatures (22, 25, 28 and 31°C) and after being acclimatized in a common temperature (26.5°C)
for over a month, they were subjected to swimming trials in order to evaluate the maximum relative critical velocity (RU
crit
) in each case. Fish that were reared in 22°C showed statistically significant lower performance than the ones reared in 31°C
(7.72 ± 0.17 vs. 8.79 ± 0.28, means ± S.E.). Possible explanations for the observed differentiation could be the effect of
early life temperature on fish muscle ontogeny or on body shape. 相似文献
8.
Jorge I. Sonnenholzner Gabriela Montaño-Moctezuma Ricardo Searcy-Bernal Alfredo Salas-Garza 《Journal of applied phycology》2011,23(3):505-513
Recently recruited urchins from the same brood, but with different initial sizes, may respond differently to similar environmental
factors. The aim of this study was to assess and compare the effects of starvation and diet on the survival, growth rates
in size and weight, and gonad index among small and large sub-adult purple sea urchins, Strongylocentrotus purpuratus. Small urchins ranged from 7.3 to 7.8 mm and large urchins from 11.8 to 14.1 mm (test diameters). Two independent experiments
were performed. In the first experiment, sea urchins were fed during 22 weeks on Egregia menziesii (ad libitum) and for only 1 day month−1 (starved condition). Feeding regime significantly affected survival, somatic growth rate in size and weight, and gonad index,
with higher means in the ad libitum treatments than in starving conditions. A recurrent cannibalism event by conspecifics
occurred in small sea urchins under starving conditions. In the second experiment, sea urchins were fed during 13 weeks ad
libitum with four diets: kelp (E. menziesii), coralline algae (Bossiella orbigniana), eelgrass (Phyllospadix scouleri) and a mixed diet of the three species. Survival was not affected by diet or urchin size, but diet significantly affected
somatic growth rate in size and weight and gonad index. Kelp promoted the highest growth rate (2.23 ± 0.21 mm month−1), the mixed diet produced an intermediate growth (1.26 ± 0.21 mm month−1), while the lowest values corresponded to coralline algae and the eelgrass (0.30 ± 0.12 and 0.10 ± 0.03 mm month−1, respectively, means ± SE). The mean growth rate of small urchins (averaging all diets) was higher than in large specimens
(1.17 ± 0.37 and 0.77 ± 0.28 mm month−1, respectively). 相似文献
9.
10.
The periodicity of otolith growth increments (opaque and translucent zones) from adult red snapper (Lutjanus campechanus) was examined through a mark and recapture study (2005–2010), and laboratory holding of hatchery reared red snapper over
a 2 year period (2002–2004). Wild red snapper (n = 295) were caught hook-and-line, marked with anchor tags, injected with oxytetracycline dihydrate (OTC), and released in
the Gulf of Mexico 15–40 km south of Dauphin Island, Alabama. Marked fish were recaptured up to 2.8 years after release (n = 35) and sagittal otoliths were dissected, sectioned and examined under white and blue-violet light. The number of opaque
growth zones past the OTC mark was compared to time at liberty for each fish and supported an annual periodicity of growth
increment formation. Also, most (87%) of the hatchery reared fish showed two opaque zones that supported an annual increment
formation rate. However, an unusual timing of opaque zone formation was shown for mark-recaptured fish. Based on known timing
of OTC marking, otoliths from mark-recapture fish showed opaque zone formation from late summer (August) to early winter (December).
This fall formation of opaque zones is in contrast to previous studies and its timing may relate to the end of spawning for
this species. 相似文献
11.
Ling Cao Biyu Song Jinmiao Zha Chengtai Yang Xinfu Gong Jianbin Li Weimin Wang 《Environmental Biology of Fishes》2009,86(1):75-88
This study presents fundamental information on the reproductive biology, size and age composition, and growth of yellow catfish,
Peltobagrus fulvidraco. Sampling was carried out monthly from Ce Lake in Hubei province from January 2004 and December 2004. Overall female/male
(F/M) sex ratio was 1.08, not significantly different from expected 1.0 ratio. But sex ratio (F/M) of the spawning group was 1.14:1 with skewness towards females (p < 0.05). The smallest sexually mature male and female massed 20.51 and 16.93 g, and measured 100.1 and 94.3 mm in total length,
respectively. Reproductive period for this species is from April to August when GSI is considerably higher than the rest months
(p < 0.05). The highest GSI values were measured from May to July for both sexes and this period was presumably the peak spawn.
First maturation occurred at age 1+ for both sexes. Fish of age 1+ and 2+ comprised the greatest portion of spawners. The absolute fecundity (AF) of P. fulvidraco ranged from 657 to 11,696 eggs per fish, with mean AF value of 3,570 ± 122 (S.D.) eggs per fish, varying considerably at
given length, weight and age. The fecundity relative to total length (F/L) fluctuated from 58 to 680 eggs/mm, with a mean value of 246 ± 34 (SD) eggs/mm, and fecundity relative to total weight (F/W) varied from 29–133 eggs/g, with a mean value of 67 ± 7 (SD) eggs/g. P. fulvidraco is a single spawner, with low fecundity compared with other Bagrid fish. 相似文献
12.
Julie Marmet Benoît Pisanu Jean-Louis Chapuis 《European Journal of Wildlife Research》2009,55(5):497-504
Home range size, range overlap, and multiyear site fidelity were investigated for introduced Siberian chipmunks (Tamias sibiricus) in a French suburban forest from bimonthly trapping sessions for 4 years (2004–2007). Annual home range sizes (100% minimum
convex polygon, ±SE) were estimated from 39 trapping histories of 28 different adult residents. Males (N = 13, 1.86 ± 0.32 ha) had a home range 2.5 times larger than females (N = 26, 0.71 ± 0.08 ha); a male home range included significantly more trapping centers (arithmetic mean of capture locations)
of females (5.5 ± 0.7) than of males (2.3 ± 0.5). Chipmunks exhibited strong multiyear site fidelity: mean distance between
annual trapping centers of individuals trapped over two successive years was small (N = 82, 26 ± 2 m) compared to the largest home range length (ranging from 36 to 281 m); overlap between annual home range sizes
of residents was 84 ± 5% (N = 11). These results improve our understanding of the space occupation of this unknown species in a novel environment. 相似文献
13.
A. B. Shrivatav K. P. Singh S. K. Mittal P. K. Malik 《European Journal of Wildlife Research》2012,58(1):365-367
Haematological and biochemical studies were conducted on 12 clinically healthy tigers of Central India. The range and mean
(with one standard deviation), respectively for the parameters examined were: red blood cells, 4.66 to 9.15, 7.9 ± 1.42, 106/μl; haemoglobin, 7.8 to 13.8, 12.8 ± 1.65 g/dl; packed cell volume, 36 to 45, 38 ± 2.54; icterus index, 2 to 5, 2 ± 1.51 U;
erythrocyte sedimentation rate, 14 to 26, 21 ± 4.21 mm at 1 h; white blood cells, 6.2 to 11.05, 8.5 ± 1.49, 103/μl; neutrophils, 57 to 75, 60 ± 5.08%; lymphocytes, 18 to 35, 30 ± 4.56%; monocytes, 2 to 6, 5 ± 1.21%; eosinophils, 2 to
6, 4 ± 1.3; basophils, 0 to 4, 1 ± 1.21; plasma albumin, 2.1 to 4.6, 3.5 ± 0.99 mg/dl; total protein, 3.7 to 8.7, 6.4 ± 1.88 mg/dl;
total bilirubin, 0.4 to 3.2, 1.9 ± 1.21 mg/dl; creatinine, 1.6 to 4.6, 2.90 ± 1.03 mg/dl; blood urea nitrogen, 6.5 to 48.2,
27.90 ± 13.77 mg/dl; glutamic pyruvic transaminase, 21.2 to 109.0, 67.88 ± 27.84 IU/L and glutamic oxaloacetate transaminase,
14.4 to 84, 57.96 ± 17.27 IU/L; index conspicuous erythrocyte sedimentation rate; absence of reticulocytes and predominance
of neutrophils. 相似文献
14.
The age of Japanese eels (Anguilla japonica) is often estimated from otoliths, but this method has not been fully validated, particularly in tropical areas where the
annulus in otolith is considered to be less distinct than in temperate areas. To validate the annuli in Japanese eel otoliths
from southern Taiwan, known-age (2 year-old) cultured eels from an eel farm and wild eels from Kao-Ping River were collected.
It was found that 26 out of 31 cultured eels (83.9%) showed two clear annuli and the remained 5 eels showed either one or
three annuli. The mean (± SD) age of the cultured eels was 1.97 ± 0.4 years. Meanwhile, a clear peak in the mean monthly marginal
increment ratio of the otolith in wild yellow and silver eels occurred once a year during winter (November to March). The
annual deposition of presumed annuli in otoliths of Japanese eel was validated and the age and growth rate estimation for
Japanese eels in the tropical southern Taiwan is deemed feasible. The growth rate of cultured eels was significantly faster
than that of wild eels, but it did not differ significantly between sexes for wild silver, yellow or cultured eels. The von
Bertalanffy Growth Function parameters (K, and t
0
) of the wild eels were estimated as 0.114 ± 0.028 year−1, 1178 ± 171 mm and −0.8 ± 0.2 years, respectively. 相似文献
15.
Midori Iida Shun Watanabe Akira Shinoda Katsumi Tsukamoto 《Environmental Biology of Fishes》2008,83(3):331-341
Ecological aspects of recruitment in the amphidromous goby, Sicyopterus japonicus, were studied from larval collections made with a set net in the estuary of the Ota River, Wakayama, Japan. The abundance
patterns of the 12,766 larvae collected from 18 April to 26 August 2006 showed several peaks during the recruitment season.
Their body sizes at recruitment ranged from 23.5 to 30.0 mm standard length (mean ± SD, 26.3 ± 1.1 mm), 0.11 to 0.49 g body
weight (0.22 ± 0.05 g), and 8 to 20 condition factor (11 ± 2). The standard length of the goby larvae tended to decrease with
the season, while their body weight slightly increased and resulted in an increase in condition factor. The recruitment of
larvae occurred mainly during the daytime. Otolith growth increment analysis of 30 larvae collected by a square lift net on
30 April 2005 revealed that the oceanic larval duration after downstream migration ranged from 173 to 253 days (208 ± 22)
after hatching. A limited time of recruitment in early summer and a considerably long duration of oceanic life (about a half
year) appeared to be unique characteristics of this Sicyopterus species that lives in a temperate region in comparison to other tropical species of the genus Sicyopterus that all have year-round recruitment. 相似文献
16.
The aim of the study was to determine the susceptibility to predation of Atlantic sturgeon larvae (Acipenser oxyrinchus) reared under traditional hatchery conditions. Experiments were conducted to determine whether predators would prey on Atlantic sturgeon if alternative prey was available and if the presence of substrate on the tank bottom impacted the number of Atlantic sturgeon consumed. European perch (Perca fluviatilis) was used as the predator, and the alternative prey were three‐spined stickleback (Gasterosteus aculeatus) or gudgeon (Gobio gobio). The predators and alternative prey were obtained from the wild. The mortality of sturgeon (n = 10) and alternative prey (n = 10) caused by four predators was recorded during 15 min trials. Trials with three‐spined stickleback and gudgeon as alternative prey were performed separately. Each experimental trial was repeated five times. The predators consumed significantly more Atlantic sturgeon than alternative prey in both the experimental setups when the bottom of the tank was covered with gravel and stone substrate and when there was no substrate. In trials with three‐spined stickleback the mortality of Atlantic sturgeon in both experimental setups was 94 ± 8.94%, while that of three‐spined stickleback in the setup with substrate was 20 ± 19.23%, and without substrate it was 22 ± 10.00%. European perch also consumed more Atlantic sturgeon than they did gudgeon, and the mean Atlantic sturgeon mortality in the experimental setup with substrate was 94 ± 5.48%, while for gudgeon it was 48 ± 8.37%. In the experimental setup without substrate the predators also consumed substantially more Atlantic sturgeon than gudgeon, with a mean Atlantic sturgeon mortality of 94 ± 8.94%, while for gudgeon it was 76 ± 5.48%. The study indicated that hatchery reared Atlantic sturgeon larvae are susceptible to predation by European perch. Predation could impact the survival of juvenile Atlantic sturgeon in the natural environment, and it could be one of the factors that is impeding the restoration of this species in the Baltic Sea basin. 相似文献
17.
Brian D. Wisenden Justin Karst Jeffrey Miller Stacey Miller Linda Fuselier 《Environmental Biology of Fishes》2008,82(1):85-92
When a predators attack prey, damaged prey tissue releases chemical information that reliably indicates an actively foraging
predator. Prey use these semiochemicals to cue anti-predator behaviour and reduce their probability of predation. Here, we
test central mudminnows, Umbra limi (Kirtland 1840), for anti-predator behavioural responses to chemical cues in conspecific skin extract. In a field experiment,
traps scented with mudminnow skin extract (alarm cue) caught fewer mudminnows than traps scented with water (control). Under
controlled laboratory conditions, mudminnows showed a significant reduction in activity and movement to the bottom in response
to alarm cues relative to water controls. Reduced activity and increased time on the bottom of the tank are both known components
of an anti-predator response. Thus, based on field and lab data, mudminnows exhibited anti-predator behavioural responses
to chemical alarm cues released by damaged epidermal tissue. Histological preparations of epidermal tissue did not reveal
the presence of specialised “alarm substance” cells for the production of chemical alarm cues. This is the first report of
an alarm reaction in an esociform, an order with a long evolutionary history of piscivory. 相似文献
18.
Brain tissue was analyzed for acetylcholinesterase (AChE) activity from 24 American pronghorn antelope (Antilocapra americana) collected on the US Army Dugway Proving Ground (DPG) (latitude 40°13' 52" N, longitude 112°45' 01" W), Tooele County, Utah.
Pronghorn antelope from DPG were evaluated against 26 pronghorn antelope collected in Wyoming. The mean AChE activity was
significantly greater (P < 0.001) in the Wyoming control group (4.612 ± 0.193 μM/gm brain tissue/min) relative to DPG (4.032 ± 0.621 μM/gm brain tissue/min).
The DPG database exhibited a fourfold greater coefficient of variation, a tenfold greater variance, and a threefold increase
in the standard deviation when compared to control AChE activity. Furthermore, the 95% confidence interval for the control
and for the DPG data were not overlapping; the entire control data set was greater than the mean DPG AChE activity. A post
hoc sequential Bonferroni statistical procedure showed two significantly (P < 0.001) distinct subsets in the DPG data. Mean DPG Subset I AChE activity (4.528 ± 0.347 μM/gm brain tissue/min) was indistinct
from the mean control AChE value (4.612 ± 0.193 μM/gm brain tissue/min). The mean DPG Subset II AChE activity (3.537 ± 0.387 μM/gm
brain tissue/min) differed significantly (P < 0.001) from the mean control AChE activity. The sum of resulting α values from the multiple statistical tests did not exceed the selected α value of P < 0.05, validating the post hoc sequential Bonferroni statistical procedure. Pronghorn antelope represented by Subset II,
experienced a 23.3% mean loss of AChE activity suggesting sub-lethal organophosphate (OP) exposure rather than a low level
chronic environmental influence was experienced by a population subset of the DPG pronghorn antelope herd. The origin of the
DPG sublethal OP exposure and its long-term effects are speculative. 相似文献
19.
The time it takes for ingested seeds to pass through the gut of animals is an important aspect of endozoochorous seed dispersal
because it influences seed dispersal distance. Variations in the physical characteristics of seeds, such as their weight,
volume, and specific gravity, can affect their movement through the gastrointestinal system of a given animal. We conducted
feeding experiments with captive Japanese martens, Martes melampus (n = 4), at Toyama Municipal Family Park Zoo, central Japan to examine the effects of the physical characteristics of seeds
on their passage times. The mean (±SD) transit time, mean retention time, and time of last appearance of four different types
of commercial seeds were 2.6 ± 0.3 h (range 0.6–5.4), 9.7 ± 1.1 h (3.8–17.3), and 23.8 ± 3.1 h (12.2–51.8), respectively.
All of these values are greater than those found during previous experiments conducted with mustelids. Similar to previous
studies, however, none of these passage time variables was correlated with the physical characteristics of seeds. Our results
thus indicate that martens disperse seeds of different plant species, whose size, volume, and specific gravity all fall within
the range of those used in the present study, from parent plants at similar distances. 相似文献
20.
Migration and reproduction of the Caspian Lamprey, Caspiomyzon wagneri, in the Shirud River were investigated during late-March to early-May at water temperatures ranging from 11 to 21.25°C. We
examined the effect of water temperature on timing of spawning migrations. There was a significant negative relationship between
temperature and intensive migration of Caspian Lamprey (p < 0.05). The most intensive migration of lampreys was at night (21:00–3:00 h) and when the water temperatures averaged 16°C
(34.43%). The overall sex ratio (male to female) was 1.07 to 1. The individual absolute fecundity was 31 ‘758–51’ 198 eggs
(mean±SD—41,924 ± 5,382). The egg diameter was 0.780–1.151 (0.92 ± 0.081) mm. The individual relative fecundity varies from
80.3 to 148.1 (107.2 ± 15.1) eggs per 1 mm of length and from 260.8 to 677.4 (397.6 ± 93) eggs per 1 g of weight. The gonadosomatic
index (GSI) of females was 5.83–31.44 (11.22 ± 4.30). 相似文献