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1.
S. D. Kashenko 《Russian Journal of Marine Biology》2009,35(5):422-430
The combined effects of temperatures of 14, 17, 20, 22, and 25°C and salinities of 36–12‰ on embryos and larvae of the sand
dollar Scaphechinus mirabilis was studied. Embryonic development is the most sensitive stage in the early ontogenesis of S. mirabilis. It is completed at a temperature of 14–20°C in a salinity range of 36–24‰ and at temperature of 22°C to 26‰. The fertilization
proceeds in wider ranges of temperature and salinity. Among the swimming larvae, blastulae showed the greatest resistance
to variations of these environmental factors. All the larvae survived at a temperature of 14–22°C and a salinity of 36–20‰,
and more than 70% of them at 18‰. The pluteus I is the most vulnerable stage; probably this is related to the formation of
the larval skeleton and transition to phytoplankton feeding. The survival of larvae at the age of 20 days was 100% at 14–22°
C and a salinity of 36–24‰, most of them survived at 14–20°C and a salinity 18‰. The temperature 25 ° C is the most damaging
for early development of S. mirabilis. The duration of development of that species lasts 28.5–29 days at 20°C and a salinity of 32.2–32.6‰. At 20 and 22°C, the
larvae settled and completed metamorphosis more quickly if sand from the parental habitat was present. The larvae did not
settle during the experiment (14 days) at 14 ° C and in the absence of sand. 相似文献
2.
Omar Hernando Avila-Poveda Sandra Liliana Lamouroux-López 《Reviews in Fish Biology and Fisheries》2007,17(1):11-19
The main objective of the current study was to determine an optimal dosage of commercial carp pituitary extract (CPE) of the
conventional heteroplastic hypophysation technique to induce spawning in the wild caught striped mojarra broodstock Eugerres plumieri under laboratory conditions. We also describe trials testing saline acclimation regimes (changes from 10‰ to 30‰) prior to
hormonal induction. For saline acclimation, three treatments were performed: first and second treatments began 1-day after
conditioning of broodstock fish with a total duration of the saline changes lasting 1-day and 2-days, respectively. The third
treatment began 30-days after conditioning with a 7-day saline regime. After reaching 30‰, all fish from the first and second
treatments died after the fourth and ninth days, respectively; while the fishes in the third treatment survived more than
two years. These fish remain on public exhibit in the “Mundo Marino” Aquarium, Santa Marta, Colombia. Four treatments of hormonal
induction were tested on females using a total concentration of 5-mg of CPE per kg of body weight: first, second and third
treatments were applied in two hormonal doses that corresponded to 10%–90%, 30%–70% and 40%–60%, respectively, with time intervals
between doses of 14-h for the first and second treatment and of 12-h for the third treatment. The fourth treatment was applied
in four hormonal doses that it corresponded to 20%–20%–30%–30% with 12-h time intervals between doses. Only the fishes of
the fourth treatment resisted the induction, continued to live and reached spawning artificially. Water temperature remained
at 28 ± 1°C and at 30‰ salinity during the study. The “dry” method of fertilization was used. The fertilized eggs were incubated
at 30‰ and 35‰ salinities. These eggs reached the Morula early stage, but were later attacked by protozoan. These results
suggest that fast changes of saline and limited hormonal dosages do not offer effective results in Eugerres plumieri. This work provided fundamental procedures for the culture and maintenance of live broodstock for striped mojarra in saltwater
and/or coastal lagoon habitats and provides an effective and viable dosage of CPE for artificial spawning and commercial production
in this species. 相似文献
3.
Klaus Anger Eduardo Spivak Tomás Luppi Claudia Bas Deborah Ismael 《Helgoland Marine Research》2008,62(2):93-102
The semiterrestrial crab Neohelice (=Chasmagnathus) granulata (Dana 1851) is a predominant species in brackish salt marshes, mangroves and estuaries. Its larvae are exported towards coastal
marine waters. In order to estimate the limits of salinity tolerance constraining larval retention in estuarine habitats,
we exposed in laboratory experiments freshly hatched zoeae to six different salinities (5–32‰). At 5‰, the larvae survived
for a maximum of 2 weeks, reaching only exceptionally the second zoeal stage, while 38% survived to the megalopa stage at
10‰. Shortest development and negligible mortality occurred at all higher salt concentrations. These observations show that
the larvae of N. granulata can tolerate a retention in the mesohaline reaches of estuaries, with a lower limit of ca. 10–15‰. Maximum survival at 25‰ suggests that polyhaline conditions rather than an export to oceanic waters are optimal for
successful larval development of this species. In another experiment, we tested the capability of the last zoeal stage (IV)
for reimmigration from coastal marine into brackish waters. Stepwise reductions of salinity during this stage allowed for
moulting to the megalopa at 4–10‰. Although survival was at these conditions reduced and development delayed, these results
suggest that already the zoea-IV stage is able to initiate the reimmigration into estuaries. After further salinity reduction,
megalopae survived in this experiment for up to >3 weeks in freshwater, without moulting to juvenile crabs. In a similar experiment
starting from the megalopa stage, successful metamorphosis occurred at 4–10‰, and juvenile growth continued in freshwater.
Although these juvenile crabs showed significantly enhanced mortality and smaller carapace width compared to a seawater control,
our results show that the late larval and early juvenile stages of N. granulata are well adapted for successful recruitment in brackish and even limnetic habitats. 相似文献
4.
Summary
Monhystera denticulata Timm, a free-living nematode present in the aufwuchs assemblages of several marine macrophytes located in North Sea Harbor, Southampton, New York, was isolated from Zostera marina and established in laboratory culture in order to study the influences of temperature and salinity on its life history. Under experimental conditions, M. denticulata has a generation time (Measured as the time elapsing between the first egg depositions of consecutive generations) of 10–12 days at 25° C and 26 S, which represent optimal growth conditions in the laboratory. The organism has a generation time of 20 days at 25° C and 13, 17 days at 25° C and 39, 18 days at 15° C and 26, 36 days at 15° C and 13 and 34 days at 15° C and 39. As conditions vary from the optimum of 25° C and 26 S, a decrease in temperature of 10° C and an increase or decrease in salinity of 13 results in a doubling of the generation time. At 5° C the generation time is about 180–197 days.Assuming optimum conditions and average generation time, about 15 generations of M. denticulata could occur in North Sea Harbor during the year. The number of generations occurring in reality is probably less, however, due to the fact that the females deposit their eggs over a period of several days.This work was supported by National Science Foundation Grant GB-19245.Contribution No. 04 from the Institute of Oceanography, City University of New York. 相似文献
5.
J. E. Bradshaw M. F. B. Dale G. E. L. Swan D. Todd R. N. Wilson 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(8):1331-1339
In 1992, 72 seedlings from each of 198 pair crosses were grown in a glasshouse, and the tubers produced by each plant were
visually assessed on a 1–9 scale of increasing preference. Three groups of four progenies with high, medium and low mean scores
were chosen to progress, without selection via tuber progenies and four-plant plots at a high-grade seed site, to replicated
yield trials in the third clonal generation. The three groups maintained their high, medium and low scores for visual preference
over the three clonal generations and also had high, medium and low scores in the second and third clonal generations for
yield, size and appearance of tubers, all of which were components of visual preference. The three groups were predicted to
have 13.6%, 1.8% and 0.2% of their clones exceeding the mean of 13 control cultivars for visual preference in the replicated
trials, and 12.1%, 4.9% and 1.4% for yield, and 56.8%, 37.1% and 14.8% for appearance. The experiment confirmed that selection
for visual preference within crosses in the seedling and first clonal generations is very ineffective, but that worthwhile
progress can be made from selection in the second clonal generation, with correlated responses for faster emergence, earlier
maturity, higher yield and greater regularity of shape (appearance). Combining selection of the high group of progenies with
selection in the second clonal generation of the best 34 out of the 120 clones in this group, produced a response in visual
preference in the third clonal generation of 1.00 compared with a maximum possible of 1.74. Ways of achieving further improvements
in early-generation selection are discussed.
Received: 26 May 1998 / Accepted: 9 June 1998 相似文献
6.
Allen PJ McEnroe M Forostyan T Cole S Nicholl MM Hodge B Cech JJ 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2011,181(8):1045-1062
We measured the ontogeny of salinity tolerance and the preparatory hypo-osmoregulatory physiological changes for seawater
entry in green sturgeon (Acipenser medirostris), an anadromous species occurring along the Pacific Coast of North America. Salinity tolerance was measured every 2 weeks
starting in 40-day post-hatch (dph) juveniles and was repeated until 100% survival at 34‰ was achieved. Fish were subjected
to step increases in salinity (5‰ 12 h−1) that culminated in a 72-h exposure to a target salinity, and treatment groups (0, 15, 20, 25, 30, 34‰; and abrupt exposure
to 34‰) were adjusted as fish developed. After 100% survival was achieved (134 dph), a second experiment tested two sizes
of fish for 28-day seawater (33‰) tolerance, and gill and gastrointestinal tract tissues were sampled. Their salinity tolerance
increased and plasma osmolality decreased with increasing size and age, and electron microscopy revealed three types of mitochondria-rich
cells: one in fresh water and two in seawater. In addition, fish held on a natural photoperiod in fresh water at 19°C showed
peaks in cortisol, thyroid hormones and gill and pyloric ceca Na+, K+-ATPase activities at body sizes associated with seawater tolerance. Therefore, salinity tolerance in green sturgeon increases
during ontogeny (e.g., as these juveniles may move down estuaries to the ocean) with increases in body size. Also, physiological
and morphological changes associated with seawater readiness increased in freshwater-reared juveniles and peaked at their
seawater-tolerant ages and body sizes. Their seawater-ready body size also matched that described for swimming performance
decreases, presumably associated with downstream movements. Therefore, juvenile green sturgeon develop structures and physiological
changes appropriate for seawater entry while growing in fresh water, indicating that hypo-osmoregulatory changes may proceed
by multiple routes in sturgeons. 相似文献
7.
The survival percentage of Drosophila melanogaster larvae on synthetic media containing different concentrations of heavy metals, including Cd, Cu, Pb, and Zn, in the first
generation indicated no significant reduction in their growth and development up to 500 ppm for all tested heavy-metal concentrations.
At 500 ppm, results showed that there was a significant reduction in pupa and adult stages: 65% and 25% for Cd, 50% and 25%
for Cu, 100% and 95% for Pb, and 85% and 75% for Zn, respectively. The survival percentages at 1000 ppm were further significantly
reduced: 15% and 0% for Cd, 35% and 15% for Cu, 45% and 90% for Pb, and 65% and 35% for Zn, respectively for pupa and adult
stages. For the second generation, there was no significant reduction in survival growth and development up to 100 ppm, but
above 500 ppm, there was a significant reduction. For most of these heavy-metal concentrations, the survival percentages of
the second generation at the pupa stage was higher than the first generation, whereas for the adult, there was a lower survival
percentage, indicating some effect on metamorphosis of these heavy-metal concentrations on Drosophila melanogaster Comparing the survival percentage between first and second generations at 500 ppm for pupa indicate a significant increase
on Cu only, and for the adult, there was a significant reduction for Cd. 相似文献
8.
The study deals with the effect of changes in salinity from 32 to 4‰ (at an interval of 4‰) on the growth, chlorophyll a and
carotenoid contents, and cell size of the benthic alga Attheya ussurensis (Bacillariophyta). A. ussurensis showed high tolerance to reduced salinity and ability to adapt to salinity changes from 16 to 12‰. In this salinity range,
the cells restored their shapes, sizes, and physiological functions. The number of cells and photosynthetic pigment content
were highest at a salinity reduction to 24‰. At 8‰, algal cells remained alive, but the process of cell division was inhibited; as a result,
the number of cells was significantly lower than in the control, the cells did not restore their sizes and shapes and remained
deformed until the end of the experiment. A drop in salinity to 4‰ caused a complete loss of cell viability of A. ussurensis within a day of exposure to this factor. 相似文献
9.
Decreases in salinity (<10%) increased the growth rates ofPhaeodactylum tricornutum and Dunaliella tertiolecta. Increasinglevels of cadmium (150 ppm (mg 11)) reduced thegrowth rates of both species. 100 ppm cadmium was lethal toD. tertiolecta but not to P. tricornutum. Lead (1 4 ppm)initially increased the growth rate of D. tertiolecta but thencaused all but the 1 ppm culture to die. Lead (14 ppm)caused a decrease in growth rate of P. tricornutum. After exposureto 1 ppm cadmium, cultures of D. tertiolecta showed an increasedtolerance to levels of cadmium, and a changed response to levelsof lead. Exposure of P. tricornutum to either cadmium or lead,or exposure of D. tertiolecta to lead caused no change in responseto either metal. 相似文献
10.
Clement K. M. Tsui K. W. Fan Raymond K. K. Chow E. B. Gareth Jones Lilian L. P. Vrijmoed 《Mycoscience》2012,53(1):1-9
We investigated the effects of salinity on the zoospore production of four mangrove thraustochytrid isolates, Schizochytrium sp. KF1, Aurantiochytrium
mangrovei KF6, Thraustochytrium striatum KF9 and Ulkenia sp. KF13. The zoospore motilities, which were based on curvilinear velocity (VCL) and straight-line velocity (VSL), were
monitored using the Computer-Assisted Sperm Motility Analysis (CASA) Software system. The zoospore production of four isolates
was suppressed at salinity above 15‰. Schizochytrium sp. produced the greatest number of zoospores at 15‰, while Aurantiochytrium mangrovei and Ulkenia sp. produced abundant zoospores in diluted sea water ranging from 7.5 to 15‰. Thraustochytrium striatum performed relatively poorly under all salinities. Salinity and exposure time, as well as their interactions, had significant
impacts on most zoospore velocity measurements. The optimal velocities of zoospore motility also varied among isolates. Zoospores
of Schizochytrium sp. and A. mangrovei had similar responses to salinity, with the highest motility at 7.3‰, followed by a decrease in velocities with increasing
salinity. In contrast, the zoospore of T. striatum had optimal motility at 12‰ and remained highly motile from 15 to 20‰. The velocities of zoospores of Ulkenia sp. were the lowest among the tested thraustochytrids and had optimal motility at 12‰. Zoospores of all the isolates remained
active after 4 h of exposure to aqueous medium, but the optimal salinity for each mode of swimming changed. The ecological
significance of these data are discussed. 相似文献
11.
Recently, heterotrophic nanoflagellates (HNF) have been reported to actively ingest prokaryotes in high salinity waters. We report the isolation and culture of an HNF from a Korean saltern pond of 300‰ salinity. The organism is biflagellated with an acronematic anterior flagellum and never glides on surfaces. The mitochondria have tubular cristae. Neither transitional helix nor spiral fiber were observed in the transition zones of the flagella. The cell has a cytostome supported by an arc of eight microtubules, suggesting that our isolate is a bicosoecid. Our isolate had neither mastigonemes, lorica, body scales, nor cytopharynx and thus could not be placed in any of the presently described bicosoecid genera. Phylogenetic analysis of 18S rRNA gene sequences from stramenopiles confirmed the bicosoecid affinities of our isolate, but did not place it within any established genus or family. Its closest relatives include Caecitellus and Cafeteria. The optimal range of growth temperature was 30–35°C. The isolated HNF grew optimally at 150‰ salinity and tolerated up to 363‰ salinity, but it failed to grow below 75‰ salinity, indicating that it could be a borderline extreme halophile. On the basis of its morphological features and position in 18S rRNA trees we propose a novel genus for our isolate; Halocafeteria, n. gen. The species name Halocafeteria seosinensis sp. nov. is proposed. 相似文献
12.
The effect of salinity on survival, osmoregulation and oxygen consumption was determined on coastal young-of-the-year (YOY)
largemouth bassMicropterus salmoides by exposing them to saline media of 0, 4, 8, 12, and 16‰. The data indicated a decrease in survival with longer exposure
time and increased salinity. There were no significant differences in plasma osmolality with increased salinity from 0 to
8‰ but osmolality was significantly greater at 12‰ than 0‰ and osmolality from 16‰ was greater than all other salinity treatments.
No significant differences in hematocrits were detected between 0 and 12‰, but hematocrits in the 16‰ treatment were significantly
reduced compared to all other treatments. YOYM. salmoides are good osmoregulators up to 8‰ but increased salinity caused measurable osmoregulatory dysfunction. Oxygen consumption
rate increased significantly as salinity increased, suggesting that adaptation of this species to hypersaline media is in
part accompanied by increased energy expenditure. 相似文献
13.
The salinity tolerance of aRhizobium meliloti strain, used as inoculum, was established by growing the strain for seven consecutive generations in a broth containing 0–1.2%
NaCl. Identical generation times and viable cell numbers were observed. Furthermore, the nodulation, plant yield and elemental
composition ofM. sativa grown on agar slopes responded identically to all inocula, irrespective of the levels of NaCl with which they were grown.
The effect of salinity on the ability ofM. sativa to grow and fix nitrogen was tested on agar slopes containing 0–1.2 % NaCl. At 0.0, 0.2 and 0.4 % NaCl the induced fixation
was identical as indicated by the constant values of nodulation and plant yield. However, a significant reduction at 0.8 and
almost a total suppression at 1.2 % NaCl occurred. Commensurate was the effect of inoculation on the elemental composition
ofM. sativa as a function of salinity at the agar medium. The concentration of Mo, Mn, Sr, Cu and Zn, is clearly affected by fixation
while salinity has no effect. Their concentration in the inoculated plants is significantly lower compared to the uninoculated
at 0–0.4 % NaCl levels, when significant fixation occurred. In contrast, at 0.8 and 1.2 % NaCl their concentration in inoculated
and uninoculated plants tends to overlap. On the other hand, the concentration of K, Rb, Br and Cl is affected mainly by salinity.
Finally, Ni is affected by neither salinity nor nitrogen fixation. 相似文献
14.
Alvaro Israel Milagrosa Martinez-Goss Michael Friedlander 《Journal of applied phycology》1999,11(6):543-549
Acclimation responses of the red alga Gracilaria tenuistipitata var. liui collected on the northwest coast of Philippines were determined in laboratory setups and outdoor cultivation tanks in Haifa,
Israel. Growth under laboratory conditions was influenced by all three variables studied, namely, temperature (20 or 30 °C), salinity (20, 30 or39‰) and seawater pH (6.5, 7.0, 8.0 or ≥ 9.0). In 250 mL flasks lacking pH control growth was influenced
by temperature only at 20 ‰, whereas at 39 ‰, growth rates were similar at 20 or 30 °C. In 500 mL cylinders in which pH was controlled, growth rates were significantly different at a pH of 6.5 and 7.0 for all
salinities, with maximal rates occurring in 39 ‰. At pH 8.0, and above, growth rates between salinities were similar and reduced
to approximately 50% at a pH of 9.0 compared to rates at a pH of 6.5. Photosynthesis responses generally resembled growth
responses both, in 250 mL and 500 mL cultures. In 40-L outdoor tanks, weekly growth and agar yields were apparently enhanced
by increasing light intensities (up to full sunlight) and nutrient concentrations (up to 0.2 mM PO3
2- and 2.0 mM NH4
+), and rates averaged four times higher than rates determined in the smaller flask cultures. This study shows broad salinity
tolerance of G. tenuistipitata var. liui and its ability to sustain growth rates that are among the highest measured for Gracilaria spp. in outdoor cultures.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
15.
The lethal and sublethal effects of tebufenozide on the survival, development, and reproduction of a field strain of tufted apple bud moth, Platynota idaeusalis (Walker) (Lepidoptera: Tortricidae), were assessed by feeding first and third instars tebufenozide-treated diet until pupation. Larval mortality was 27.4 and 44.7% at 0.1 and 0.2 ppm for first instars and 21.9 and 57.8% at 0.2 and 0.4 ppm for third instars, respectively. Treated larvae exhibited higher pupal mortalities, lower pupal weights, and generally more deformed adults than untreated larvae. Larval development was not affected by tebufenozide when neonates were exposed, but development was accelerated slightly at 0.4 ppm for both males and females when third instars were exposed. All treatments produced sex ratios biased toward males. When paired with either treated or untreated males, females resulting from neonates treated at 0.2 ppm and from third instars treated at both 0.2 and 0.4 ppm laid from 37 to 65% fewer eggs. A reduction in fertility was only found when third instars were treated at the higher 0.4 ppm rate. These results suggest that tebufenozide can exhibit a significant effect on the population dynamics of the tufted apple bud moth. 相似文献
16.
Kazuyoshi Kuwano Shingo Matsuka Shigeki Kono Masayori Ninomiya Junichi Onishi Naotsune Saga 《Journal of applied phycology》1998,10(1):9-14
The growth of Laurencia okamurae and the content of laurinterol and debromolaurinterol were influenced by various factors.
Temperature influenced growth raere te with a maximum at 25°C, regardless of daylength. Maturity depended on temperature rather
than daylength; the plants grew without maturing at 15°C, while the plants matured within two weeks at 25°C. The plants were
able to grow at salinities of 14–50‰ with maximum growth at 26‰. The salinities growth rash;50‰te reduced with decreasing
concentration of nitrate below 1.2 × 10-3 M, and of total phosphate below 7.5× 10-8 M. Bromide concentration had no effect on growth, and the plants grew without bromide. Variation in temperature between 15–25°C
and daylength produced no obvious change in laurinterol and debromolaurinterol contents. On the other hand, an increase in
salinity led to an increase for both. The plants cultured in a completely artificial medium, modified ASP12NTA, showed a marked drop in their content of these metabolites. An increase in concentrations of nitrate, total phosphate
or bromide did not restore the content.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
17.
H. G. Choi Y. S. Kim J. H. Kim S. J. Lee E. J. Park J. Ryu K. W. Nam 《Journal of applied phycology》2006,18(3-5):269-277
Effects of temperature and salinity on the growth of the two agarophytes, Gracilaria verrucosa (Hudson) Papenfuss and Gracilaria chorda Holmes were examined in Korea. Both species grew over a wide range of temperatures (10–30 ∘C) and salinities (5–35‰), and grew well at 17–30 ∘C and a salinity of 15–30‰. In culture, G. verrucosa grew faster than G. chorda and their maximum growth rates were 4.95% day−1 (30 ∘C, 25‰) and 4.47% day−1 (at 25 ∘C, 25‰), respectively. In the field population the maximum growth and fertility of G. chorda were observed in summer. The growth rate of G. verrucosa was slightly higher than that of G. chorda for 2 weeks on the cultivation rope and in culture but it was much lower after being contaminated with epiphytes. The biomass of the epiphytes was 0.82 g dry wt. per host plant in G. verrucosa and 0.001 g in G. chorda. G. chorda exhibited resistance to epiphytism and grew 7 times in length and the dry weight increased 15 times after 55 days. In conclusion, G. chorda appears to be a good agarophyte with a fast growth rate and resistance to epiphytesm, and compared with G. verrucosa, has good potential for commercial cultivation. 相似文献
18.
The salinity tolerance of aRhizobium meliloti strain isolated from salt-affected soils was examined. Growth of the strain on yeast—mannitol broth containing 0–1.2% NaCl
exhibited in all cases the same generation time and simultaneous onset of the stationary phase while the total viable number
of cells was the same for three continuous generations. The nodulation, plant yield and elemental composition ofMedicago sativa plants grown on agar slopes, inoculated with cultures from the third generation grown on broth containing 0–1.2% NaCl responded
identically to all inocula. The salinity tolerance of the strain in fixing nitrogen was furthermore demonstrated withM. sativa plants grown on either nitrogen-free agar slopes containing 0.2–1.2% NaCl or soil-agar slopes with saline soil in which 0.15
and 0.3% additional NaCl was used. 相似文献
19.
The purpose of this study was to determine the seasonal water use patterns of dominant macrophytes coexisting in the coastal
Everglades ecotone. We measured the stable isotope signatures in plant xylem water of Rhizophora mangle, Cladium jamaicense, and Sesuvium portulacastrum during the dry (DS) and wet (WS) seasons in the estuarine ecotone along Taylor River in Everglades National Park, FL, USA.
Shallow soilwater and deeper groundwater salinity was also measured to extrapolate the salinity encountered by plants at their
rooting zone. Average soil water oxygen isotope ratios (δ
18O) was enriched (4.8 ± 0.2‰) in the DS relative to the WS (0.0 ± 0.1‰), but groundwater δ
18O remained constant between seasons (DS: 2.2 ± 0.4‰; WS: 2.1 ± 0.1‰). There was an inversion in interstitial salinity patterns
across the soil profile between seasons. In the DS, shallow water was euhaline [i.e., 43 practical salinity units (PSU)] while
groundwater was less saline (18 PSU). In the WS, however, shallow water was fresh (i.e., 0 PSU) but groundwater remained brackish
(14 PSU). All plants utilized 100% (shallow) freshwater during the WS, but in the DS R. mangle switched to a soil–groundwater mix (δ 55% groundwater) while C. jamaicense and S. portulacastrum continued to use euhaline shallow water. In the DS, based on δ
18O data, the roots of R. mangle roots were exposed to salinities of 25.4 ± 1.4 PSU, less saline than either C. jamaicense (39.1 ± 2.2 PSU) or S. portulacastrum (38.6 ± 2.5 PSU). Although the salinity tolerance of C. jamaicense is not known, it is unlikely that long-term exposure to high salinity is conducive to the persistence of this freshwater
marsh sedge. This study increases our ecological understanding of how water uptake patterns of individual plants can contribute
to ecosystem levels changes, not only in the southeast saline Everglades, but also in estuaries in general in response to
global sea level rise and human-induced changes in freshwater flows. 相似文献
20.
Douglas P. Middaugh Michael J. Hemmer Yara Lamadrid-Rose 《Environmental Biology of Fishes》1986,15(2):107-117
Synopsis Spawning patterns of inland silversides, Menidia beryllina, and tidewater silversides, Menidia peninsulae, were examined in the laboratory under several combinations of ‘tidal’ and diel light cycle cues. M. beryllina showed a high frequency of spawning throughout the day when held under constant conditions (24L: OD, current velocity 8 cm
sec−1) and when ‘tidal’ and diel light cycles were presented singly or in combination. In contrast, M. peninsulae demonstrated a high frequency of spawning only when presented a combination of ‘tidal’ and diel light cycle cues and spawned
predominantly at night. Menidia beryllina embryos were euryhaline. Hatching ranged from 73 to 78% at salinities of 5,15 and 30‰ M. peninsulae embryos showed an inverse relationship between the percentage hatch and the incubation salinity, 90% at 5‰ and only 65% at
30‰ Survival and growth of larval M. beryllina from the day of hatching through 16 days old was optimal at 15‰ Although survival of M. peninsulae larvae was optimal at 30%, no trend was apparent in growth of larvae held for 16 days at 5, 15 or 30‰ salinity.
Contribution No. 508 from the Gulf Breeze Environmental Research Laboratory 相似文献