Intraspecific variation in Hydrogen Ion and Aluminum Toxicity in Bufo americanus and Ambystoma maculatum

1987 ◽  
Vol 44 (9) ◽  
pp. 1622-1628 ◽  
Author(s):  
Karen L. Clark ◽  
Bruce D. LaZerte
Keyword(s):  
Significant Variation ◽  
Hatching Success ◽  
Aluminum Toxicity ◽  
Natural Populations ◽  
Acid Tolerance ◽  
Ambystoma Maculatum ◽  
Hydrogen Ion ◽  
Perivitelline Space ◽  
Laboratory Studies ◽  
Bufo Americanus

Variation in hydrogen ion and aluminum toxicity was measured among clutches in one Bufo americanus population from a pond with pH 5.96 and both among clutches and ponds in four Ambystoma maculatum populations from ponds with pH levels from 4.44 to 6.19. There was significant variation among clutches, but in general, B. americanus hatching success was reduced at pH 4.1 compared with pH6.0. At pH 4.1,200 μg Al/L caused even greater embryonic mortality. Aluminum toxicity did not vary among clutches; however, variation in acid tolerance was such that clutches with the highest hatching success at pH 6.0 had the lowest hatching success at pH 4.1. Hatching success of A. maculatum also varied among clutches, but in general, hatching success was lower at pH 4.3 than at pH 6.0, and 200 μg Al/L at pH 4.3 increased hatching success compared with when no aluminum was present. Variation in acid tolerance among pond populations was so large that one population had higher hatching success at pH 4.3 than at pH 6.0. Ambystoma maculatum hatching success was not related to diameter of the perivitelline space just prior to hatch. The wide variation in acid tolerance among clutches of B. americanus and among populations of A. maculatum suggests that laboratory studies using small numbers of clutches may not adequately represent the response of the natural populations.

A Laboratory Study of the Effects of Aluminum and pH on Amphibian Eggs and Tadpoles

1985 ◽  
Vol 42 (9) ◽  
pp. 1544-1551 ◽  
Author(s):  
Karen L. Clark ◽  
Bruce D. Lazerte
Keyword(s):  
Laboratory Study ◽  
Egg Size ◽  
Hatching Success ◽  
Rana Sylvatica ◽  
Consistent Pattern ◽  
Hydrogen Ion ◽  
Aluminum Stress ◽  
Bufo Americanus ◽  
Aluminum Speciation ◽  
Laboratory Bioassays

Bufo americanus and Rana sylvatica eggs and tadpoles were exposed in laboratory bioassays to a range of pH and aluminum concentrations commonly encountered in ponds and streams of central Ontario. Bufo americanus and R. sylvatica hatching success was reduced at pH 4.14. The addition of 10 μg inorganic monomeric aluminum (IMAl)/L at pH < 4.35 further reduced hatching success of B. americanus. Rana sylvatica was slightly less sensitive, with hatching success being reduced by addition of 20 μg IMAl/L at pH 4.14. Increasing aluminum concentrations at pH 4.14 appeared to have no further effect except at the highest level used (200 μg/L). IMAI that was toxic at pH 4.35 or 4.14 had no effect at pH 4.75 or 5.75. Toxicity was not dependent on the aluminum speciation, since similar levels of Al3+ and Al(OH)x complexes that were toxic at pH 4.14 were not toxic at pH 4.75; also, Al(F)x complexes were as toxic as Al3+. Egg mortality due to hydrogen ion stress was correlated with a delay in time of hatch and a reduction in egg size; however, there was no consistent pattern with respect to aluminum stress. Bufo americanus and R. sylvatica tadpoles were not sensitive to up to 200 μg IMAl/L and pH as low as 4.14.

Effects of elevated hydrogen ion and aluminum concentrations on the survival of amphibian embryos and larvae

1985 ◽  
Vol 63 (1) ◽  
pp. 116-123 ◽  
Author(s):  
Karen L. Clark ◽  
Ronald J. Hall
Keyword(s):  
Hatching Success ◽  
Rana Sylvatica ◽  
Larval Survival ◽  
Hydrogen Ion ◽  
Ph Effects ◽  
Bufo Americanus ◽  
Amphibian Species ◽  
Egg Hatching ◽  
Effects Of Ph ◽  
Chemical Variable

Egg hatching success was measured for three amphibian species (Bufo americanus, Rana sylvatica, and Ambystoma maculatum) exposed to varying hydrogen ion, aluminum, and dissolved organic carbon (DOC) concentrations. In the first experiment, hatching success in six stream pools was negatively correlated with Al and DOC and positively correlated with pH. Effects of any one chemical variable, however, could not be separated from the others. In a second experiment, to separate effects of pH and Al from DOC, eggs and larvae were exposed to simulated stream pools in which pH was reduced. At pH 4.8 and 37 μg/L inorganic monomeric Al, only eggs of A. maculatum were affected. At pH 4.3, 46 μg/L inorganic monomeric Al was more toxic (compared with 34–35 μg/L at pH 4.8 and 4.3) to B. americanus and R. sylvatica embryos. Bufo americanus was more sensitive to low pH and elevated Al than R. sylvatica. Mortality of eggs of both species mainly occurred within 1 day of exposure but continued until hatching. Mortality of A. maculatum eggs, however, did not occur during the 4 days of acidification, but 2–3 weeks later, at the time of hatching. Larval survival in general was not affected by reduced pH (pH 4.3) and (or) elevated Al (up to 46 μg/L inorganic monomeric Al).

population ecology of the Australian frog Crinia signifera: egg-laying patterns and egg mortality

1994 ◽  
Vol 21 (6) ◽  
pp. 621 ◽  
Author(s):  
I Williamson ◽  
CM Bull
Keyword(s):  
Population Ecology ◽  
Water Body ◽  
Significant Variation ◽  
Hatching Success ◽  
Egg Laying ◽  
Egg Mass ◽  
Egg Mortality ◽  
Different Depths ◽  
Small Clusters ◽  
Overall Mortality

There are few studies of embryo mortality in anurans, and most of these studies deal with anurans that deposit clutches as one egg mass. In this study, egg mortality in Crinia signifera, an anuran that distributes its clutches in small clusters of eggs, was examined with the aims of: (i) determining overall mortality levels, and (ii) determining whether there was significant variation in success between clutches laid by different females. Hatching success varied significantly between years and between habitats, and was as low as 2% in some habitats in some years. Fungal infection caused most mortality, and hatching success was higher in temporary pools than in a permanent water body. Although significant variation in clutch success between females could occur if clutches were laid in different habitats or at different times, it was not clear whether there would be significant variation in clutch success between females laying simultaneously in the same water body. Differences in success of clutches might occur if females distributed eggs at different depths or in different-sized clusters. However, information on inter-female variation in these components of egg-laying behaviour in C. signifera is currently unavailable.

Germination in Stylosanthes humilis Populations in the Presence of NaCl

1994 ◽  
Vol 42 (6) ◽  
pp. 717 ◽  
Author(s):  
MB Lovato ◽  
PS Martins ◽  
Filho JPD Lemos
Keyword(s):  
Salt Tolerance ◽  
Significant Variation ◽  
Germination Rate ◽  
Natural Populations ◽  
Germination Percentage ◽  
Percentage Germination ◽  
North East ◽  
Germination Response ◽  
Stylosanthes Humilis

The germination response to NaCl treatments (0, 67, 134, 201 and 268 mol m-3) was investigated in 6 natural populations of Stylosanthes humilis from 3 ecogeographic regions of Pernambuco State, north-east Brazil. In general, salt tolerance was high, with percentage germination unaltered up to 67 mol m-3 NaCl in 2 populations and unaltered up to 134 mol m-3 NaCl in the remaining 4. The estimated concentration which reduced percentage germination to 50% varied between populations from 200 to 295 mol m-3 NaCl. Salt affected germination rate even more than it did the germination percentage, being altered at 67 mol m-3 NaCl in all populations. The germination rate was reduced to 50% in the range of 131-176 mol m-3 NaCl. There was a significant variation in salt tolerance between these natural populations, and no relation was found between salt tolerance of the populations and the aridity of their provenance.

Toxicity of Amphibian Breeding Ponds in the Sudbury Region

1993 ◽  
Vol 50 (7) ◽  
pp. 1497-1503 ◽  
Author(s):  
Joseph Freda ◽  
D. Gordon McDonald
Keyword(s):  
Organic Compounds ◽  
Rana Sylvatica ◽  
Low Ph ◽  
Ambystoma Maculatum ◽  
Bufo Americanus ◽  
Spotted Salamander ◽  
Water Ph ◽  
Dissolved Organic Compounds ◽  
High Concentrations ◽  
Toad Bufo

We measured the survival of transplanted embryos and tadpoles of the wood frog (Rana sylvatica), the American toad (Bufo americanus), and the spotted salamander (Ambystoma maculatum) in 16 ponds located approximately 60 km south of Sudbury, Ontario. Mortality of embryos of all species and mortality of B. americanus tadpoles were correlated only with water pH. In two low-pH ponds, high concentrations of dissolved organic compounds might have been a toxic component. Aluminum and pH were correlated with mortality for only R. sylvatica tadpoles. Overall, Al did not appear to be very toxic in both laboratory and field exposures possibly due to complexation by dissolved organic compounds.

The influence of external cation concentration on the hatching of amphibian embryos in water of low pH

1985 ◽  
Vol 63 (11) ◽  
pp. 2649-2656 ◽  
Author(s):  
Joseph Freda ◽  
William A. Dunson
Keyword(s):  
Rana Sylvatica ◽  
Low Ph ◽  
Early Mortality ◽  
Ambystoma Maculatum ◽  
Perivitelline Space ◽  
Acidic Water ◽  
Cation Concentration ◽  
Amphibian Embryos ◽  
Ambystoma Jeffersonianum

Amphibian embryos exposed to water of low pH were killed by two distinct mechanisms. At very low pH levels, embryos stopped development soon after exposure to test solutions. At higher but still lethal pH levels, embryos became curled within a shrunken perivitelline space and failed to hatch (curling defect). The addition of Ca, Mg, and to a lesser extent Na (> 10 mg/L), prevented the early mortality of embryos in acidic water. However, increasing concentrations of these ions also caused the curling defect. Embryos of Ambystoma maculatum and Ambystoma jeffersonianum were generally able to hatch even though they became curled, but Rana sylvatica remained trapped and died. Consequently, as the concentration of Ca, Mg, or Na was increased at low pH, greater numbers of embryos of A. maculatum and A. jeffersonianum hatched, while survival of embryos of R. sylvatica was drastically reduced.

scholarly journals ENZYMES AND REPRODUCTION IN NATURAL POPULATIONS OF DROSOPHILA EURONOTUS

Genetics ◽  
1976 ◽  
Vol 84 (2) ◽  
pp. 375-384
Author(s):  
Harrison D Stalker
Keyword(s):  
Sexual Maturity ◽  
Multiple Mating ◽  
Natural Populations ◽  
Allele Frequencies ◽  
Laboratory Studies ◽  
Enzyme Locus ◽  
Chromosomal Locus ◽  
Large Numbers ◽  
True Frequency ◽  
Two Populations

ABSTRACT Populations of Drosophila euronotus, one from southern Louisiana (3 samples), and one from Missouri (2 samples), were classified for allele frequencies at alkaline phosphatase (APH) and acid phosphatase (ACPH) loci. The two populations differed consistently in allele frequencies at both loci. The APH locus is on the inversion-free X chromosome; the chromosomal locus of the autosomal ACPH is unknown, and could involve inversion polymorphism. Wild females from Missouri and Louisiana populations heterozygous at the APH locus carried more sperm at capture than did the corresponding homozygotes. This heterotic association was significant for the combined samples, and whether it was the result of heterosis at the enzyme locus studied, or due to geographically widespread close linkage with other heterotic loci, it should help to maintain heterozygosity at the APH locus. In a Louisiana collection which included large numbers of sperm-free females, simultaneous homozygosity at both enzyme loci was significantly associated with lack of sperm. It is suggested that the latter association is the result of young heterozygous females achieving sexual maturity earlier than do the double homozygotes. The average effective sperm load for 225 wild females was only 29.4, suggesting the necessity for frequent repeat-mating in nature to maintain female fertility. A comparison of the sex-linked APH genotypes of wild females with those of their daughters indicated that among 295 wild-inseminated females from five populations, 35% had mated more than once, and of this 35%, six females had mated at least three times. Because of ascertainment difficulties, it is clear that the true frequency of multiple-mating in nature must have been much higher than the observed 35%. Laboratory studies indicate that multiple-mating in this species does not involve sperm displacement, possibly due to the small number of sperms transmitted per mating, and the fact that the sperm receptacles are only partially filled by a given mating.

scholarly journals Variation in Y Chromosome Segregation in Natural Populations of Drosophila melanogaster

Genetics ◽  
1987 ◽  
Vol 115 (1) ◽  
pp. 143-151
Author(s):  
Andrew G Clark
Keyword(s):  
Drosophila Melanogaster ◽  
Y Chromosome ◽  
Chromosome Segregation ◽  
Significant Variation ◽  
Natural Populations ◽  
Meiotic Drive ◽  
Adult Offspring ◽  
Functional Variation ◽  
Y Chromosomes ◽  
Geographic Origins

ABSTRACT Functional variation among Y chromosomes in natural populations of Drosophila melanogaster was assayed by a segregation study. A total of 36 Y chromosomes was extracted and ten generations of replacement backcrossing yielded stocks with Y chromosomes in two different genetic backgrounds. Eleven of the Y chromosomes were from diverse geographic origins, and the remaining 25 were from locally captured flies. Segregation of sexes in adult offspring was scored for the four possible crosses among the two backgrounds with each Y chromosome. Although the design confounds meiotic drive and effects on viability, statistical partitioning of these effects reveals significant variation among lines in Y chromosome segregation. Results are discussed in regards to models of Y-linked segregation and viability effects, which suggest that Y-linked adaptive polymorphism is unlikely.

Clutch parameters and reproductive success of a translocated population of red-crowned parakeet (Cyanoramphus novaezelandiae)

2008 ◽  
Vol 56 (6) ◽  
pp. 389 ◽  
Author(s):  
Luis Ortiz-Catedral ◽  
Dianne H. Brunton
Keyword(s):  
Reproductive Success ◽  
Clutch Size ◽  
Brood Size ◽  
Reproductive Output ◽  
Hatching Success ◽  
Natural Populations ◽  
Reproductive Potential ◽  
Breeding Pair ◽  
Brood Rearing ◽  
Breeding Seasons

At least four populations of the red-crowned parakeet (Cyanoramphus novaezelandiae) have been established via translocation within New Zealand over the last 40 years, but reproductive parameters of these populations have not been documented. We quantified differences in clutch parameters and reproductive success for a translocated population of this species on Tiritiri Matangi Island over two breeding seasons. Overall clutch parameters and estimates of reproductive success were consistent with reported values from natural populations. However, we found previously unreported differences in clutch size, hatching success and brood size between breeding seasons. The number of fledglings produced per breeding pair increased significantly from 1.4 to 3.4 fledglings during our two-year study. In contrast, egg volume and fertility per clutch did not vary during the same period. Overall, 7 eggs were laid per breeding pair but only 2.22 nestlings fledged, representing a 63.8% loss of initial reproductive potential. Losses during the incubation stage were caused by partial and total hatching failure, whereas starvation of nestlings caused all losses during the brood-rearing stage. Hatching success during our study was lower than that reported for wild populations of this and other parrot species, and remained lower even during the most productive breeding season. We found no cases of predation on eggs or nestlings during our study despite the presence of native and exotic avian predators on Tiritiri Matangi Island. We show that clutch size, brood size and changes in loss between breeding seasons are determinants of reproductive output in translocated red-crowned parakeet and also that reproductive output can vary greatly between breeding seasons. Finally, if reduced hatching success is the result of small founder size, management of parakeets should consider the movement of larger and more genetically diverse flocks.

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