REPRODUCTION 



In Bangladesh, the breeding season is initiated at the onset of 

 the first seasonal rains, usually mid-April. R^roductive activity is 

 intense through mid-July (K. Z. Husain, personal ccninunication ) . A 

 seasonal rainfall will activate feeding and reproductive behavior. An 

 early (February 1982) rainfall at Mymensingh was sufficient to initiate 

 breeding re^xanses. The larvae survived and subsequently metamorphosed 

 because of abundant standing water. At Barisal, aseasonal rain induced 

 breeding activity, but the larvae failed to survive in the absence of 

 standing water. Rana tigrina , therefore, is an opportunistic breeder 

 in which rainfall elicits reproductive behavioral responses. R^roduc- 

 tive activity continues well into the nonsoonal season, diminishing in 

 intensity and frequency correlative to the decrease in intensity and 

 frequency of rainfall. 



Rana tigrina oviposits in "new water" of the monsoon rather than 

 in stagnant waters depleted of oxygen. In "new water" less particulate 

 matter is present, the tenperature is lover and the oxygen content is 

 higher. Ihe abiotic reqmrements for larval develc^xtent are, in part, 

 fulfilled. 



At the advent of the breeding cycle the males, the first to ennerge 

 from underground retreats, begin frenetic pre-reproductive activities, 

 establishing territories by emitting !^)ecies-qpecific calls. The voice- 

 less female is thereby attracted to the territorial male. The chonasing 

 males are highly vulnerable to predators. 



Daniel (1975) observed similar reproductive behavior in Rana 

 tigrina near Bombay, India. The males, lemon-yellow in color, congre- 

 gate in rainwater pools and ditches, chorusing loudly as they await the 

 females. The arriving females are fought over, the nearest male claw- 

 ing the fotale, fending off conpetitors by kicking strongly with the 

 hind legs. Ihe spawn is d^xjsited in rainwater pools and in other tran- 

 sitory waters. The ova float upon d^xssition, thence sink to the bottom 

 where they remain until hatching. 



Dutta and NkDhanty-Hejmadi (1978) conclvded that Rana tigrina has 

 the most r^id developmental rate among local (Vani Vihar, Bhubaneswar, 

 India) aitphibians. At the aforanentioned localities hatching occurs 

 23 hours postfertilization, external gills at 44 3/4 hours, limb buds 

 at 19 days, well defined limbs and tail at 30 days, and complete meta- 

 morphosis at 33 days. Rana tigrina attains metamorphosis at 43 days 

 postfertilization under controlled laboratory conditions. Breeding 

 during the monsoon and rapid larval development permit escape from the 

 pressures of dessication and diminished larval predation attendant qpon 

 other synpatric anphibian species (Dutta and Mc*ianty-He jmadi , 1978). 



