scholarly journals The return to water in ancestral Xenopus was accompanied by a novel mechanism for producing and shaping vocal signals

2018 ◽  
Author(s):  
Ursula Kwong-Brown ◽  
Martha L. Tobias ◽  
Damian O. Elias ◽  
Ian C. Hall ◽  
Coen P.H. Elemans ◽  
...  
Keyword(s):  
Sound Production ◽  
Neuromuscular Control ◽  
Current Theory ◽  
Species Divergence ◽  
Species Identity ◽  
Rapid Separation ◽  
Resonance Modes ◽  
Acoustic Signature ◽  
Vocal Signals ◽  
Species Specific

AbstractSpecies-specific vocal signals allow listeners to locate potential mates. During the tetrapod transition from water to land, lungs replaced gills, allowing expiration to drive sound production. Several groups, e.g. cetaceans and some frogs, then returned to water. Here we explore how air-driven sound production changed upon re-entry and how essential acoustic information on species identity was preserved in the secondarily aquatic frog Xenopus. We filmed movements of cartilage and muscles during evoked sound production in isolated larynges. Our results refute the current theory for Xenopus vocalization, cavitation, and instead favor sound production by mechanical excitation of laryngeal resonance modes following rapid separation of laryngeal arytenoid discs. The resulting frequency resonance modes (dyads) are intrinsic to the larynx rather than due to neuromuscular control. We show that dyads are a distinctive acoustic signature across species. While dyad component frequencies overlap across species, their ratio is shared within each Xenopus clade and thus provide information on species identity, potentially facilitating both conspecific localization and ancient species divergence.

scholarly journals The return to water in ancestral Xenopus was accompanied by a novel mechanism for producing and shaping vocal signals

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Ursula Kwong-Brown ◽  
Martha L Tobias ◽  
Damian O Elias ◽  
Ian C Hall ◽  
Coen PH Elemans ◽  
...  
Keyword(s):  
Sound Production ◽  
Neuromuscular Control ◽  
Current Theory ◽  
Editorial Note ◽  
Species Identity ◽  
Rapid Separation ◽  
Resonance Modes ◽  
Acoustic Signature ◽  
Vocal Signals ◽  
Species Specific

Listeners locate potential mates using species-specific vocal signals. As tetrapods transitioned from water to land, lungs replaced gills, allowing expiration to drive sound production. Some frogs then returned to water. Here we explore how air-driven sound production changed upon re-entry to preserve essential acoustic information on species identity in the secondarily aquatic frog genus Xenopus. We filmed movements of cartilage and muscles during evoked sound production in isolated larynges. Results refute the current theory for Xenopus vocalization, cavitation, and favor instead sound production by mechanical excitation of laryngeal resonance modes following rapid separation of laryngeal arytenoid discs. Resulting frequency resonance modes (dyads) are intrinsic to the larynx rather than due to neuromuscular control. Dyads are a distinctive acoustic signature. While their component frequencies overlap across species, their ratio is shared within each Xenopus clade providing information on species identity that could facilitate both conspecific localization and ancient species divergence.Editorial note: This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (<xref ref-type="decision-letter" rid="SA1">see decision letter</xref>).

Species identity matters: Functional responses to warming in congeneric turfs differ from those of a canopy algae but are species-specific

2021 ◽  
pp. 107396
Author(s):  
Isabella Provera ◽  
Cristina Piñeiro-Corbeira ◽  
Rodolfo Barreiro ◽  
Laura Díaz-Acosta ◽  
Pilar Díaz-Tapia
Keyword(s):  
Functional Responses ◽  
Species Identity ◽  
Species Specific ◽  
Canopy Algae

scholarly journals Acoustic communication and the evolution of hearing in fishes

2000 ◽  
Vol 355 (1401) ◽  
pp. 1285-1288 ◽  
Author(s):  
Friedrich Ladich
Keyword(s):  
Inner Ear ◽  
Acoustic Communication ◽  
Acoustic Signals ◽  
Spectral Content ◽  
Auditory Thresholds ◽  
Selective Pressures ◽  
Vocal Signals ◽  
Species Specific ◽  
Hearing Abilities ◽  
Dominant Frequencies

Fishes have evolved a diversity of sound–generating organs and acoustic signals of various temporal and spectral content. Additionally, representatives of many teleost families such as otophysines, anabantoids, mormyrids and holocentrids possess accessory structures that enhance hearing abilities by acoustically coupling air–filled cavities to the inner ear. Contrary to the accessory hearing structures such as Weberian ossicles in otophysines and suprabranchial chambers in anabantoids, sonic organs do not occur in all members of these taxa. Comparison of audiograms among nine representatives of seven otophysan families from four orders revealed major differences in auditory sensitivity, especially at higher frequencies (> 1kHz) where thresholds differed by up to 50 dB. These differences showed no apparent correspondence to the ability to produce sounds (vocal versus non–vocal species) or to the spectral content of species–specific sounds. In anabantoids, the lowest auditory thresholds were found in the blue gourami Trichogaster trichopterus , a species not thought to be vocal. Dominant frequencies of sounds corresponded with optimal hearing bandwidth in two out of three vocalizing species. Based on these results, it is concluded that the selective pressures involved in the evolution of accessory hearing structures and in the design of vocal signals were other than those serving to optimize acoustic communication.

scholarly journals The importance of motivation, weapons, and foul odors in driving encounter competition in carnivores

2020 ◽  
Author(s):  
ML Allen ◽  
CC Wilmers ◽  
LM Elbroch ◽  
JM Golla ◽  
Heiko Wittmer
Keyword(s):  
Interference Competition ◽  
Current Theory ◽  
Lynx Rufus ◽  
Natural Environments ◽  
Ecological Communities ◽  
Competitive Advantages ◽  
Ecological Society ◽  
Strategic Behaviors ◽  
Species Specific ◽  
Occurrence Patterns

© 2016 by the Ecological Society of America. Encounter competition is interference competition in which animals directly contend for resources. Ecological theory predicts the trait that determines the resource holding potential (RHP), and hence the winner of encounter competition, is most often body size or mass. The difficulties of observing encounter competition in complex organisms in natural environments, however, has limited opportunities to test this theory across diverse species. We studied the outcome of encounter competition contests among mesocarnivores at deer carcasses in California to determine the most important variables for winning these contests. We found some support for current theory in that body mass is important in determining the winner of encounter competition, but we found that other factors including hunger and species-specific traits were also important. In particular, our top models were "strength and hunger" and "size and hunger," with models emphasizing the complexity of variables influencing outcomes of encounter competition. In addition, our wins above predicted (WAP) statistic suggests that an important aspect that determines the winner of encounter competition is species-specific advantages that increase their RHP, as bobcats (Lynx rufus) and spotted skunks (Spilogale gracilis) won more often than predicted based on mass. In complex organisms, such as mesocarnivores, species-specific adaptations, including strategic behaviors, aggressiveness, and weapons, contribute to competitive advantages and may allow certain species to take control or defend resources better than others. Our results help explain how interspecific competition shapes the occurrence patterns of species in ecological communities.

The Effects of Cross-Fostering On the Behavior of Two Species of North American Lemmings, Dicrostonyx Groenlandicus and Lemmus Trimucronatus. Iii. Agonistic Behavior

Behaviour ◽  
1980 ◽  
Vol 73 (3-4) ◽  
pp. 261-275 ◽  
Author(s):  
Edwin M. Banks ◽  
U. William Huck
Keyword(s):  
Agonistic Behavior ◽  
Species Identity ◽  
Maternal Environment ◽  
Response Range ◽  
Dicrostonyx Groenlandicus ◽  
Specific Manner ◽  
Species Specific ◽  
Cross Fostering ◽  
Species Cross

Abstract1. The role of the maternal environment in development of species-specific agonistic behavior was investigated by reciprocally cross-fostering two species of lemmings (Discrostonyx groenlandicus and Lemmus trimucronatus). Non-fostered and within-species-fostered (in-fostered) animals served as controls. 2. When adult, cross-fostered male lemmings engaged in more frequent contact social behavior with the foster species than with conspecifics. However, since cross-fostered animals retained their ability to interact with conspecifics in a species-specific manner, cross-fostering appears to have resulted in a broadening of "species identity" to include the foster species. 3. In-fostering reduced the aggressiveness of Dicrostonyx but had little effect on the behavior of Lemmus. 4. Both the intensity and orientation of agonistic behavior were altered as a result of cross-fostering. In Dicrostonyx, a highly aggressive species, cross-fostering resulted in decreased aggression directed at the foster species and increased aggression toward conspecifics. In Lemmus, a less aggressive species, cross-fostering appears to have resulted in a broadening of the response range to stimuli provided by the foster species. When paired with aggressive Dicrostonyx, cross-fostered Lemmus engaged in more frequent and intense aggression than did controls. However, when paired with nonaggressive (in-fostered) Dicrostonyx, cross-fostered Lemmus engaged in less frequent and intense aggression than controls. In contrast, non-fostered and in-fostered Lemmus males had a relatively narrow response range to Dicrostonyx. 5. In general, the results suggested that agonistic behaviour in lemmings is the product of a complex interaction between genotype and maternal environment.

scholarly journals Evolution of Courtship Songs in Xenopus: Vocal Pattern Generation and Sound Production

2015 ◽  
Vol 145 (3-4) ◽  
pp. 302-314 ◽  
Author(s):  
Elizabeth C. Leininger ◽  
Darcy B. Kelley
Keyword(s):  
Sex Differences ◽  
Evolutionary History ◽  
Molecular Mechanisms ◽  
Sound Production ◽  
Pattern Generation ◽  
Model Species ◽  
Extant Species ◽  
Evolutionary Trajectories ◽  
Strong Candidate ◽  
Species Specific

The extant species of African clawed frogs (Xenopus and Silurana) provide an opportunity to link the evolution of vocal characters to changes in the responsible cellular and molecular mechanisms. In this review, we integrate several robust lines of research: evolutionary trajectories of Xenopus vocalizations, cellular and circuit-level mechanisms of vocalization in selected Xenopus model species, and Xenopus evolutionary history and speciation mechanisms. Integrating recent findings allows us to generate and test specific hypotheses about the evolution of Xenopus vocal circuits. We propose that reduced vocal sex differences in some Xenopus species result from species-specific losses of sexually differentiated neural and neuromuscular features. Modification of sex-hormone-regulated developmental mechanisms is a strong candidate mechanism for reduced vocal sex differences.

scholarly journals Recording of “sonic attacks” on U.S. diplomats in Cuba spectrally matches the echoing call of a Caribbean cricket

2019 ◽  
Author(s):  
Alexander L. Stubbs ◽  
Fernando Montealegre-Z
Keyword(s):  
Sound Production ◽  
The United States ◽  
Health Problems ◽  
Medical Evidence ◽  
Cognitive Difficulties ◽  
Acoustic Signature ◽  
Rigorous Research ◽  
Pulse Structure ◽  
Sound Pulses ◽  
The U.S

Beginning in late 2016, diplomats posted to the United States embassy in Cuba began to experience unexplained health problems—including ear pain, tinnitus, vertigo, and cognitive difficulties1–4—which reportedly began after they heard1,2 strange noises in their homes or hotel rooms. In response, the U.S. government dramatically reduced1–3 the number of diplomats posted at the U.S. embassy in Havana. U.S. officials initially believed1,2,5 a sonic attack might be responsible for their ailments. The sound linked to these attacks, which has been described as a “high-pitched beam of sound”, was recorded by U.S. personnel in Cuba and released by the Associated Press (AP). Because these recordings are the only available non-medical evidence of the sonic attacks, much attention has focused on identifying health problems6–11 and the origin12–17 of the acoustic signal. As shown here, the calling song of the Indies short-tailed cricket (Anurogryllus celerinictus) matches, in nuanced detail, the AP recording in duration, pulse repetition rate, power spectrum, pulse rate stability, and oscillations per pulse. The AP recording also exhibits frequency decay in individual pulses, a distinct acoustic signature of cricket sound production. While the temporal pulse structure in the recording is unlike any natural insect source, when the cricket call is played on a loudspeaker and recorded indoors, the interaction of reflected sound pulses yields a sound virtually indistinguishable from the AP sample. This provides strong evidence that an echoing cricket call, rather than a sonic attack or other technological device, is responsible for the sound in the released recording. Although the causes of the health problems reported by embassy personnel are beyond the scope of this paper, our findings highlight the need for more rigorous research into the source of these ailments, including the potential psychogenic effects, as well as possible physiological explanations unrelated to sonic attacks.

scholarly journals Taxonomic Relevance of Calcium Oxalate Cuticular Deposits in Dracaena Vand. ex L.

HortScience ◽  
2001 ◽  
Vol 36 (6) ◽  
pp. 1033-1036 ◽  
Author(s):  
Svoboda V. Pennisi ◽  
Dennis B. McConnell
Keyword(s):  
Calcium Oxalate ◽  
Individual Species ◽  
Leaf Epidermis ◽  
Rapid Separation ◽  
Taxonomic Key ◽  
Species Specific ◽  
Tree Group

Detection of cuticular crystals in the 14 species of Dracaena examined indicated that they are probably ubiquitous throughout the genus and may permit rapid separation of dracaenas from plants with similar leaves such as the cordylines (Cordyline sp.). Dracaena species of the dragon tree group deposit the greatest quantity of uniformly small cuticular crystals. However, the distinction between individual species within this grouping, based solely on crystal numbers and size, is not sufficient for taxonomic separation. All other species of Dracaena studied did display species-specific quantities and sizes of cuticular crystals. This, in combination with characteristics of the leaf epidermis, could serve as part of a taxonomic key to the genus.

scholarly journals What drives the assembly of plant-associated protist microbiomes?

2020 ◽  
Author(s):  
Kenneth Dumack ◽  
Kai Feng ◽  
Sebastian Flues ◽  
Melanie Sapp ◽  
Susanne Schreiter ◽  
...  
Keyword(s):  
Plant Species ◽  
Beta Diversity ◽  
Small World ◽  
Strong Impact ◽  
Dominant Group ◽  
Environmental Filters ◽  
Species Identity ◽  
Scale Free ◽  
Network Analyses ◽  
Species Specific

AbstractIn a field experiment we investigated the influence of the environmental filters soil type and plant species identity on rhizosphere community assembly of Cercozoa, a dominant group of (mostly bacterivorous) soil protists. The experiment was set up with two plant species, lettuce and potato, grown in an experimental plot system with three contrasting soils. Plant species (14%) and rhizosphere origin (vs. bulk soil) with 13%, together explained four times more variation in cercozoan beta diversity than the three soil types (7% explained variation in beta diversity). Our results clearly confirm the existence of plant species-specific protist communities. Network analyses of bacteria-Cercozoa rhizosphere communities identified scale-free small world topologies, indicating mechanisms of self-organization. While the assembly of rhizosphere bacterial communities is bottom-up controlled through the resource supply from root (secondary) metabolites, our results support the hypothesis that the net effect may depend on the strength of top-down control by protist grazers. Since grazing of protists has a strong impact on the composition and functioning of bacteria communities, protists expand the repertoire of plant genes by functional traits, and should be considered as ‘protist microbiomes’ in analogy to ‘bacterial microbiomes’.HighlightMicrobiomes of rhizosphere protists are plant species-specific and tightly co-evolving with their bacterial prey, thereby extending and modifying the functional repertoire of the bacterial-plant symbiosis.

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