98 



INDUCED BREEDING 



Name 



Size Range: mm. 



males females 



Number 

 Eggs 



Egg size 

 (mm) 



Breeding 

 Period 



Induced 

 Breeding 



Acris gryllus. 



Bufo americanus_ 

 Bufo fowleri 



Hyla andersonil_ 



Hyla cinereus_ 



Hyla crucifer 



Hyla versicolor— 



15-30 

 52-86 

 51-75 

 30-41 



36-48 



18-30 

 32-52 



Pseudacris brachyphona 



Pseudacris nigrita f 



Pseudacris nigrita f 



Rana catesbiana 



Rana clamitans 



Rana palustris 



Rana pipiens_ 



Rana septentrionalis- 



Rana sphenocephala 



Rana sylvatica 



Rana virgatipes 



30 



30 



32 



180 



95 



64 



80 



72 



78 



60 



63 



16-33 

 54-110 

 55-84 

 38-48 



32-48 



20-34 

 33-60 



27-35 



22-34 



20-38 



90-200 



60-100 



50-80 



54-102 



50-76 



53-82 



34-70 



41-66 



250 



4000-8000 



4000-8000 



Laid 



singly 



Small 



groups 



800-1000 



30-40 

 in groups 



500-800 

 6000-8000 

 2000-4000 

 2000-3000 

 2000-3000 



2000-3000 

 200-600 



0. 9-1. 



1. 0-1. 4 

 1. 0-1. 4 

 1. 2-1. 4 



0. 8-1. 6 



0.9-1. 1 



1. 1-1. 2 



0.9-1. 1 



0. 9-1. 2 



1. 2-1. 7 

 1. 5 

 1.6 

 1.6 



? 



1.6 

 1. 8-2. 4 

 1. 5-1. 8 



Feb. -Oct. 

 Apr. -Aug. 1 

 Apr. -Aug. 1 5 

 May 1 -Aug. 1 



Apr. 15-Aug. 15 



Apr. 1 -June 1 5 

 Apr. -Aug. 1 5 



Mar. 



Feb. 



Mar. 



June' 



June 



Apr. 



Apr. 



June 



Feb. 



Mar. 



Apr. 



-June 

 -May 15 



15-May 20 

 -Aug. 

 1-Aug. 15 

 15-May 15 

 1-May 15 

 15-Aug. 15 

 -Dec. 



15-May 1 

 -Aug. 15 



Almost anytime 

 Oct. to Apr. 

 Nov. to Apr. 

 Oct. to Apr. 



Nov. to Mar. 



Oct. to Mar. 

 Nov. to Mar. 



Sept. to Apr. 

 Sept. to Apr. 

 Aug. 20-Feb. 

 May -Aug. 

 Nov. to July 

 Oct. to Mar. 

 Sept. 1 -May 1 

 Nov. to May 

 All year 

 Sept. to Mar. 

 Nov. to Mar. 



DATA ON EGG SIZE, EGG PRODUCTION, AND PERIOD 

 FOR OVULATION INDUCTION 



MODIFICATIONS OF THE PROCEDURE 



A. ANURA 



Rana : 



The procedure as outlined is satislaclory for Rana pipiens Irorn about September I until 

 the normal breeding season of the species in April. The procedure for other species of 

 Anura is essentially the same except for the season, the dose of the hormone, and the 

 source of the hormone. 



The above table indicates that it is possible to secure Anuran eggs at any season of the 

 year, providing the appropriate species is chosen. Since there is also considerable over- 

 lapping of susceptible seasons, material is available for hybridization experiments. 

 Properly planned, amphibian eggs can be available for experimentation at all times. The 

 genus Rana is available over wide areas, and their normal breeding season varies con- 

 siderably. 



The dose of the hormone varies somewhat, depending both on the donor and the recipient. 

 In general the larger species seem to require more of the glands from the smaller spe- 

 cies. In none of the genus Rana has there been uniform success with any source but other 

 amphibian glands, the mammalian extracts being generally negative. 



Bufo : 



The toad will react not only to the pituitaries from other Anura but also to the pituitaries 

 from other Phyla, to the extracts of mammalian pituitaries and even to the extract of 

 pregnancy urine (antuirtin-S) and Preloban (Xenopus). The response is most reliable, 

 however, when either frog or toad pituitaries are used. 



