. The ecology and life history of the common frog (Rana temporaria temporaria). Rana temporaria. PARASITES AND PREDATORS 6i On 13th August there was a relatively large peak, which must have been due to secondary larvae, for by this tune all the primary larvae would have fomid hosts or have died. Fig. 22 is an extreme example of the importance of secondary infestation in late-metamorphosing. O 20 30 APRIL o 20 30 MAY 19 29 JUNE. Fig. 20. Mean Numbers of Polystoma per Tadpole in Upper Parkfield Pond, 1947 The black dots and solid line indicate neotenics, the open circles and thin Une the larvae.
. The ecology and life history of the common frog (Rana temporaria temporaria). Rana temporaria. PARASITES AND PREDATORS 6i On 13th August there was a relatively large peak, which must have been due to secondary larvae, for by this tune all the primary larvae would have fomid hosts or have died. Fig. 22 is an extreme example of the importance of secondary infestation in late-metamorphosing. O 20 30 APRIL o 20 30 MAY 19 29 JUNE. Fig. 20. Mean Numbers of Polystoma per Tadpole in Upper Parkfield Pond, 1947 The black dots and solid line indicate neotenics, the open circles and thin Une the larvae. Note the two larval peaks and some sign of a third. Note also that the scale of this diagram is different from Figs. 21 and 22, because the parasites were far more numerous than in the other cases. tadpoles. The infestation in this pond, Dagger Lane 1947, was so low early in the season that none were found until i6th June, but, during July, enough secondary larvae had arrived to give a moderate infesta- tion. Since, however, there were by then not many tadpoles, the total number of infested litde frogs must have been very small. I think that these graphs and others in the references cited show that the comphcated life history of the parasite is an adaptation to the wide differences in the time of metamorphosis which I have already described. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Savage, Ronald Maxwell. New York, Hafner Pub. Co.
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Keywords: ., bookcentury1900, bookcollectionbiodiv, booksubjectranatemporaria
