Biology subjects

Hugo F. Gante

Publications and source records attributed to Hugo F. Gante.

2 recordsLinked to original sources

bioRxiv2016

Social selection maintains honesty of a dynamic visual signal in cichlid fish

How honest signals evolve is a question that has been hotly debated by animal communication theoreticians and for which empirical evidence has been difficult to obtain. Theory predicts that, due to strong conflicts of interest, communication in aggressive contexts should be under strong selection for clear and reliable signaling. On the other hand, context-dependent signaling increases cheating opportunities, depending on how senders and receivers use, acquire and process signal information. Using animal signaling theory, theoretical visual models and behavioral experimentation, we characterize and determine proximate honesty mechanisms of the facial coloration in the Princess of Burundi cichlid, Neolamprologus brichardi, a species with complex social interactions. We show that this facial color pattern evolved stable chromatic conspicuousness for efficient transmission in the aquatic environment, while context-dependent plasticity in luminance of the horizontal black stripe element is used to signal switches in aggressive intent. Importantly, using experimental signal manipulation we demonstrate that social selection by receiver retaliation is the mechanism responsible for maintaining signal honesty. We suggest that by affecting the evolution of pigmentation patterns in sexually monochromatic cichlid species, social selection can have potential impacts on diversification dynamics.

Evolutionary Biology↗

bioRxiv2016

Singing above the chorus: cooperative Princess cichlid fish (Neolamprologus pulcher) has high pitch

Teleost fishes not only communicate with well-known visual cues, but also olfactory and acoustic signals. Communicating with sound has advantages, as signals propagate fast, omnidirectionally, around obstacles, and over long distances. Heterogeneous environments might favour multimodal communication, especially in socially complex species, as combination of modalities strengths helps overcome their individual limitations. Cichlid fishes are known to be vocal, but a recent report suggests that this is not the case for the socially complex Princess cichlid Neolamprologus pulcher from Lake Tanganyika. Here we further investigated acoustic communication in this species. Wild and captive N. pulcher produced high frequency sounds (mean: 12 kHz), when stimulated by mirror images. In laboratory experiments, N. pulcher produced distinct two-pulsed calls mostly, but not exclusively, associated with agonistic displays. Our results suggest that male N. pulcher produce more sounds at greater durations than females. Thus, we confirm that the Princess cichlid does not produce low frequency sounds, but does produce high frequency sounds, both in combination with and independent from visual displays, suggesting that sounds are not a by-product of displays. Further studies on the hearing abilities of N. pulcher are needed to clarify if the high-frequency sounds are used in intra-or inter-specific communication.

Animal Behavior and Cognition↗