Problems of an Amphibian Supply House

Emmons, Marvin B.

doi:10.1093/icb/13.1.91

Cited by 5 publications

(1 citation statement)

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“…The effect of harvesting on amphibian populations is poorly known, but there is evidence that it can be significant. Emmons (1973) noted that ‘As early as 1918, tons of frogs were moved by Railway Express out of the tri‐state area of North and South Dakota and Minneapolis …’ (p. 91) for use as fresh frog legs. He then added, ‘It is not uncommon [in 1973] for some [amphibian supply] houses to voluntarily eliminate certain species of turtles and amphibians from their current list of offerings in efforts to protect diminishing supplies in nature’ (p. 91).…”

Section: Six Hypothesesmentioning

confidence: 99%

Global amphibian declines: sorting the hypotheses

Collins¹,

Storfer²

2003

Diversity and Distributions

835

518

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Abstract. Reports of malformed amphibians and global amphibian declines have led to public concern, particularly because amphibians are thought to be indicator species of overall environmental health. The topic also draws scientific attention because there is no obvious, simple answer to the question of what is causing amphibian declines? Complex interactions of several anthropogenic factors are probably at work, and understanding amphibian declines may thus serve as a model for understanding species declines in general. While we have fewer answers than we would like, there are six leading hypotheses that we sort into two classes. For class I hypotheses, alien species, over-exploitation and land use change, we have a good understanding of the ecological mechanisms underlying declines; these causes have affected amphibian populations negatively for more than a century. However, the question remains as to whether the magnitude of these negative effects increased in the 1980s, as scientists began to notice a global decline of amphibians. Further, remedies for these problems are not simple. For class II hypotheses, global change (including UV radiation and global climate change), contaminants and emerging infectious diseases we have a poor, but improving understanding of how each might cause declines. Class II factors involve complex and subtle mechanistic underpinnings, with probable interactions among multiple ecological and evolutionary variables. They may also interact with class I hypotheses. Suspected mechanisms associated with class II hypotheses are relatively recent, dating from at least the middle of the 20th century. Did these causes act independently or in concert with preexisting negative forces of class I hypotheses to increase the rate of amphibian declines to a level that drew global attention? We need more studies that connect the suspected mechanisms underlying both classes of hypotheses with quantitative changes in amphibian population sizes and species numbers. An important step forward in this task is clarifying the hypotheses and conditions under which the various causes operate alone or together.

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Section: Six Hypothesesmentioning

confidence: 99%

Global amphibian declines: sorting the hypotheses

Collins¹,

Storfer²

2003

Diversity and Distributions

835

518

View full text Add to dashboard Cite

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Studies of the development of frog hemopoietic tissue in vitro. I. Spleen culture assay of an erythropoietic factor in anemic frog blood

Carver

Meints

1977

J. Exp. Zool.

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A new in vitro technique has been described for demonstrating the presence of an erythropoietic factor in the circulating blood of frogs. The assay system consisted of MC33 medium, erythropoietically active spleen cells from Rana pipiens, and plasma or serum from frogs made anemic via phenylhydrazine or bleeding. The spleen cells, which remain erythropoietically active for up to nine days, were found to incorporate 59Fe, [3H]thymidine, [3H]uridine, and [3H]leucine at a greater rate in the presence of plasma or serum from anemic versus normal frogs. The hormones triiodothyronine, prolactin, and erythropoietin were not effective in eliciting an hemopoietic response. The data presented suggest that the spleen from that adult frog is a major site of erythroid differentiation and maturation.

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Biology and Diseases of Amphibians

Anver¹,

Pond²

1984

Laboratory Animal Medicine

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Problems of an Amphibian Supply House

Cited by 5 publications

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Global amphibian declines: sorting the hypotheses

Global amphibian declines: sorting the hypotheses

Studies of the development of frog hemopoietic tissue in vitro. I. Spleen culture assay of an erythropoietic factor in anemic frog blood

Biology and Diseases of Amphibians

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