Abstract
ABSTRACTTransitions between aquatic and terrestrial prey capture are challenging. Trophic shifts demand a high degree of behavioral flexibility to account for different physical circumstances between water and air to keep performance in both environments. The Himalayan newt, Tylototriton verrucosus, is mostly terrestrial but becomes aquatic during its short breeding period. Nonetheless, it was assumed that it lacks the capability of trophic behavioral flexibility, only captures prey on land by its tongue (lingual prehension) and does not feed in water. This theory was challenged from stomach content analyses in wild populations that found a variety of aquatic invertebrates in the newts' stomachs during their breeding season. Accordingly, we hypothesized that T. verrucosus actively changes its terrestrial prey capture mechanism to hunt for aquatic prey at least during its aquatic stage. In fact, the kinematic analyses showed that T. verrucosus uses lingual prehension to capture prey on land but changes to suction feeding for aquatic strikes. The statistical analyses revealed that terrestrial and aquatic strikes differ significantly in most kinematic parameters while behavioral variability does not differ between both behaviors. In turn, the movement patterns in suction feeding showed a higher degree of coordination between jaw and hyoid movements compared to the putative primary feeding mode, namely lingual prehension. We conclude that T. verrucosus, though relatively slow compared to trophic specialists, benefits from a high degree of behavioral flexibility that allows exploiting food sources efficiently from two very different habitats.
Highlights
Salamanders can capture prey in aquatic and terrestrial habitats
Despite the suggestion by Miller and Larsen (1989) that the Himalayan newts could not be induced to feed in water, we hypothesized that T. verrucosus is capable of behavioral flexibility by modifying its prey capture strategy to feed in water
This assumption was based on the observations that: (i) T. verrucosus is not exclusively terrestrial but exhibits an aquatic phase at least during its breeding season (Dasgupta, 1996; Thorn, 1968); and (ii) analyses of stomach contents of wild populations revealed that Himalyan newts fed on a variety of aquatic organisms during the monsoon season when they seek aquatic habitats to breed (Dasgupta, 1996)
Summary
Salamanders can capture prey in aquatic and terrestrial habitats. The main challenge of trophic habitat switches are the different demands on the prey capture apparatus due to the physical differences between water and air, such as differences in density and viscosity When animals feed in both environments they can use the same set of movements, they will perform suboptimally in at least one of the two environments; alternatively they can alter their feeding behavior to increase efficiency (Bramble, 1973; Stayton, 2011)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
