J>^ 



BREED ING HAB ITS OF AMPH IB lA 



The breeding season depends upon the latitude, but ranges from June to August. The 

 air temperature must be at least 72°F. and the bottom water temperature at least 66°C. be- 

 fore the eggs are layed. The eggs are small, but as many as 20,000 may be layed by a 

 single female, and the egg Jelly is loosely applied. The eggs will develop between 59°F. 

 and 90°F. , and the hatching span at 68°F. is about l^k hours. There is a long larval (tad- 

 pole) life, the mature tadpole of *+ to 6 Inches total length being 

 ready to metamorphose 2 or 5 years after the egg is layed. Meta- 

 morphosis generally occurs in late July and in August. 



RANA CLAMITAJfS. the green frog. This frog is found where bullfrogs 

 are found but they prefer permanent, plant-grown aquatic ponds, 

 swamps, meadows, and slow streams. It is a common form in Eastern 

 North America, even at considerable altitudes. 



The green frog can be recognized by its predominantly green 

 back, with small and widely separated spots, paired ridges of skin 

 from the eyes backward along the back, and webbed and pointed toes 

 as in the bullfrog. It is rarely more than k inches in body length. 

 The tympanum is usually very large, and this is the most readily 

 determined difference between the greenfrog and immature bullfrogs. 



The tadpoles, which grow slowly, feed on diatoms, and algae; 

 the young frogs and adults eat insects, Crustacea, spiders, snails, 

 earthworms. The food consists largely of non-aquatic forms. 



Tlie male Raiia clami- 

 tans, tlie green frog, 

 with inflated vocal 

 sacs as seen from 

 above. 



(Courtesy C. H. Pope 

 1941+ : Chicago Mus. 

 Nat. Hist.) 



Typical amplexus of Rana clamitans; 

 lateral view. 



Egg-laying pos- 

 ture of Rana 

 clamitans just 

 prior to tlie on- 

 set of the ovl- 

 position; dorsal 

 view. 



I'pstroke of the 

 male Rana clam- 

 itans and the 

 appearance of 

 the first batch 

 of eggs; dorsal 

 view. 



Downstroke of 

 t)ie male Rana 

 clamitans and 

 tlie formation 

 of the surface 

 film; dorsal 

 view. 



(From Aronaon 19'^5 : Am. Mus. Nov. #122U. Artist Mr. M. Sorensen) 



The male has a yellowish throat but also a yellow spot or ring In the center of Its 

 tympanum, and its head is wider than that of the female. Breeding occurs in quiet, shal- 

 low plant -grown ponds from May to August, generally in late June and early July, even in 

 the same latitude and environment. The eggs may number as many as 5,000 and they are ap- 

 proximately the size of those of Eana pipiens, 1.5 mm. in diameter. The eggs and tadpoles 

 can tolerate a low oxygen environment, the tadpoles generally hibernating in mud for one 

 winter and then quickly passing through metamorphosis in early Spring at 570 to UOO days. 

 Low temperatures are disastrous, the embryos being unable to survive lO'-'C. The time lapse 

 from stage #12 to gill circulation at 15°C. ia about 220 hours. 



SANA PALUSTRIS. the pickerel frog. This is also known as the Spring Leopard Frog, and is 

 found largely in the East, in sphagnum bogs or in cool clear water surrounded by high 

 grass and other vegetation. The adults rarely exceed 5 inches in body length. 



