Meeting Abstract
Walking catfish (Clarias batrachus) are an invasive species in Florida, renowned for their air-breathing and terrestrial locomotor capabilities. However, it is unknown how they orient in a terrestrial environment. Furthermore, while anecdotal life history information is widespread for this species in its nonnative range, little of this information exists in the literature. The goals of this study were to identify sensory modalities that walking catfish use to orient on land, and to describe the natural history of this species in its nonnative range. Fish (n = 100) were collected from around Ruskin, FL, and housed in a greenhouse, where experiments took place. Individual catfish were placed in the center of a terrestrial arena and were exposed to four treatments: deionized water- and alanine solution-wetted bench liner in direct contact with the fish, and pools of filtered and pond water out of direct view or contact. Additionally, 88 people from Florida wildlife-related Facebook groups who have personal observations of walking catfish on land were interviewed for information regarding their terrestrial natural history. This data was combined with observations from 38 YouTube videos of walking catfish in Florida. Walking catfish exhibited significantly positive chemotaxis toward alanine, suggesting chemoreception is important to their terrestrial orientation. Walking catfish emerge most frequently during or just after heavy summer rains, particularly from storm drains in urban areas, where they may feed on terrestrial invertebrates. By better understanding the full life history of walking catfish, we can improve management of this invasive species.
