We tracked the spawning habitat use of two native stream gobies (Rhinogobius fluviatilis and Rhinogobius nagoyae) before and during the invasion of a non-native goby (Rhinogobius sp. OR) and after its disappearance in the Tani River, Japan. Throughout the three phases, the majority of the two native gobies showed high preference and use for the habitat with medium-fast current velocity and coarse substrates as spawning sites. When the non-native Rhinogobius sp. OR invaded, the majority of them also preferred and used the same habitat as spawning sites, and the spawning habitat use of the three Rhinogobius species substantially overlapped. These results suggest that the invasion by the non-native goby did not significantly change the spawning habitat use of the two native gobies. However, the similar habitat requirement among the three Rhinogobius species may cause competition for the spawning habitat when the availability of their favorite habitat is greatly restricted. The non-native Rhinogobius sp. OR could utilize the spawning space on the undersurface of nest stones more efficiently than the two native gobies. Therefore, in the non-native Rhinogobius sp. OR, the size of nest stones is unlikely to be a limiting factor for reproductive success. Such ecological characteristics on nest stone use may enable Rhinogobius sp. OR to easily acquire nest stones with less competition in the spawning habitat where they coexist, which have also helped Rhinogobius sp. OR to extend its distribution area.

我们追踪了两种本地河流虾虎鱼（Rhinogobius fluviatilis和Rhinogobius nagoyae）在非本地虾虎鱼（Rhinogobius sp. OR）入侵之前和期间以及它在日本谷川消失后的产卵栖息地使用情况。在这三个阶段中，两种原生虾虎鱼中的大多数表现出对中速流速和粗糙基质的栖息地作为产卵地点的高度偏好和利用。当非本地Rhinogobius sp。或入侵，它们中的大多数也喜欢和使用与产卵地点相同的栖息地，而三只犀牛的产卵栖息地使用物种基本重叠。这些结果表明，非本地虾虎鱼的入侵并没有显着改变两种本地虾虎鱼的产卵栖息地。然而，当它们最喜欢的栖息地的可用性受到极大限制时，三种犀牛物种之间相似的栖息地要求可能会导致产卵栖息地的竞争。非本地Rhinogobius sp。OR可以比两个原生虾虎鱼更有效地利用巢石下表面的产卵空间。因此，在非本地Rhinogobius sp. 或者，巢石的大小不太可能成为繁殖成功的限制因素。巢石使用的这种生态特征可能使Rhinogobiussp. 或者在它们共存的产卵栖息地中以较少的竞争轻松获得巢石，这也有助于Rhinogobius sp。或扩大其分布区域。