Odendaal F J, Bull C M, Nias R C
School of Biological Sciences, Flinders University, 5042, Bedford Park, South Australia.
Department of Biological Sciences, Stanford University, 94305, Stanford, Ca, USA.
Oecologia. 1982 Jan;52(3):411-414. doi: 10.1007/BF00367968.
Two leptodactylid frog species Ranidella signifera and R. riparia occupy adjacent but different habitat types in the Flinders Ranges of South Australia. R. signifera is found in slow-flowing creeks with mud or sand substrates. R. riparia occupies fast-flowing rocky creeks. The two coexist in a narrow overlap zone with heterogeneous habitats. Laboratory experiments were used to test habitat preferences of tadpoles in a tub with sand and rock substrates. R. riparia was most commonly found on the rock substrate. R. signifera showed no distinct preference for sand, but when mixed with R. riparia increased its use of the habitat in the spaces between and under rocks. This was particularly apparent in flowing water where 81% of all R. signifera tadpoles were observed in this sheltered habitat.The data suggest that R. signifera tadpoles have reduced fitness in flowing water because they cannot exploit exposed feeding sites where most of the algae grow, and that interspecific interactions with R. riparia tadpoles reduce their fitness further. This helps to explain why R. signifera do not extend their distribution into R. riparia occupied creeks. The data do not explain why R. riparia do not colonize the slow muddy creeks occupied by R. signifera.
两种细趾蟾科蛙类，即细纹姬蛙（Ranidella signifera）和溪姬蛙（R. riparia），栖息在南澳大利亚弗林德斯山脉相邻但不同的栖息地类型中。细纹姬蛙见于水流缓慢、有泥或沙质基质的小溪。溪姬蛙占据水流湍急的岩石小溪。二者在一个具有异质栖息地的狭窄重叠区域共存。实验室实验用于在一个有沙质和岩石基质的水槽中测试蝌蚪的栖息地偏好。溪姬蛙最常出现在岩石基质上。细纹姬蛙对沙地没有明显偏好，但与溪姬蛙混养时，会增加其对岩石之间和下方空间栖息地的利用。这在流动水中尤为明显，所有细纹姬蛙蝌蚪中有81%在这个有遮蔽的栖息地中被观察到。数据表明，细纹姬蛙蝌蚪在流动水中适应性降低，因为它们无法利用大多数藻类生长的暴露觅食地点，并且与溪姬蛙蝌蚪的种间相互作用进一步降低了它们的适应性。这有助于解释为什么细纹姬蛙不会将其分布范围扩展到溪姬蛙占据的小溪中。这些数据并未解释为什么溪姬蛙没有在细纹姬蛙占据的缓慢泥泞小溪中定殖。
