scholarly journals Sound signatures and production mechanisms of three species of pipefishes (Family: Syngnathidae)

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1471 ◽  
Author(s):  
Adam Chee Ooi Lim ◽  
Ving Ching Chong ◽  
Chiow San Wong ◽  
Sithi Vinayakam Muniandy
Keyword(s):  
Variable Structure ◽  
Acoustic Signals ◽  
Cranial Bone ◽  
Cranial Morphology ◽  
Acoustic Signatures ◽  
Fish Feeds ◽  
Double Staining Method ◽  
Species Specific ◽  
Cranial Kinesis ◽  
Production Mechanisms

Background.Syngnathid fishes produce three kinds of sounds, named click, growl and purr. These sounds are generated by different mechanisms to give a consistent signal pattern or signature which is believed to play a role in intraspecific and interspecific communication. Commonly known sounds are produced when the fish feeds (click, purr) or is under duress (growl). While there are more acoustic studies on seahorses, pipefishes have not received much attention. Here we document the differences in feeding click signals between three species of pipefishes and relate them to cranial morphology and kinesis, or the sound-producing mechanism.Methods.The feeding clicks of two species of freshwater pipefishes,Doryichthys martensiiandDoryichthys deokhathoidesand one species of estuarine pipefish,Syngnathoides biaculeatus, were recorded by a hydrophone in acoustic dampened tanks. The acoustic signals were analysed using time-scale distribution (or scalogram) based on wavelet transform. A detailed time-varying analysis of the spectral contents of the localized acoustic signal was obtained by jointly interpreting the oscillogram, scalogram and power spectrum. The heads of bothDoryichthysspecies were prepared for microtomographical scans which were analysed using a 3D imaging software. Additionally, the cranial bones of all three species were examined using a clearing and double-staining method for histological studies.Results.The sound characteristics of the feeding click of the pipefish is species-specific, appearing to be dependent on three bones: the supraoccipital, 1st postcranial plate and 2nd postcranial plate. The sounds are generated when the head of theDorichthyespipefishes flexes backward during the feeding strike, as the supraoccipital slides backwards, striking and pushing the 1st postcranial plate against (and striking) the 2nd postcranial plate. In theSyngnathoidespipefish, in the absence of the 1st postcranial plate, the supraoccipital rubs against the 2nd postcranial plate twice as it is pulled backward and released on the return. Cranial morphology and kinesis produce acoustic signals consistent with the bone strikes that produce sharp energy spikes (discrete or merged), or stridulations between bones that produce repeated or multimodal sinusoidal waveforms.Discussion.The variable structure of the sound-producing mechanism explains the unique acoustic signatures of the three species of pipefish. The differences in cranial bone morphology, cranial kinesis and acoustic signatures among pipefishes (and seahorses) could be attributed to independent evolution within the Syngnathidae, which warrants further investigation.

scholarly journals Comparative cranial biomechanics in two lizard species: impact of variation in cranial design

2021 ◽  
pp. jeb.234831
Author(s):  
Hugo Dutel ◽  
Flora Gröning ◽  
Alana C. Sharp ◽  
Peter J. Watson ◽  
Anthony Herrel ◽  
...  
Keyword(s):  
Cranial Bone ◽  
Cranial Morphology ◽  
Bone Strain ◽  
Lizard Species ◽  
Simulation Techniques ◽  
Lower Strain ◽  
Structural Resistance ◽  
Computer Based ◽  
Morphological Differences ◽  
Species Specific

Cranial morphology in lepidosaurs is highly disparate and characterized by the frequent loss or reduction of bony elements. In varanids and geckos, the loss of the postorbital bar is associated with changes in skull shape, but the mechanical principles underlying this variation remain poorly understood. Here, we seek to determine how the overall cranial architecture and the presence of the postorbital bar relate to the loading and deformation of the cranial bones during biting in lepidosaurs. Using computer-based simulation techniques, we compare cranial biomechanics in the varanid Varanus niloticus and the teiid Salvator merianae, two large, active foragers. The overall strain magnitudes and distribution across the cranium is similar in both species, despite lower strain gradients in Varanus niloticus. In Salvator merianae, the postorbital bar is important for the resistance of the cranium to feeding loads. The postorbital ligament, which partially replaces the postorbital bar in varanids, does not affect bone strain. Our results suggest that the reduction of the postorbital bar impaired neither biting performance nor the structural resistance of the cranium to feeding loads in Varanus niloticus. Differences in bone strain between the two species might reflect demands imposed by feeding and non-feeding functions on cranial shape. Beyond variation in cranial bone strain related to species-specific morphological differences, our results reveal that similar mechanical behaviour is shared by lizards with distinct cranial shapes. Contrary to mammals, the morphology of the circumorbital region, calvaria and palate appears to be important for withstanding high feeding loads in these lizards.

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.

Linear correlates in the speech signal: The orderly output constraint

1998 ◽  
Vol 21 (2) ◽  
pp. 241-259 ◽  
Author(s):  
Harvey M. Sussman ◽  
David Fruchter ◽  
Jon Hilbert ◽  
Joseph Sirosh
Keyword(s):  
Speech Signal ◽  
Speech Sound ◽  
Acoustic Signals ◽  
Barn Owl ◽  
Critical Parameters ◽  
Place Of Articulation ◽  
Mustached Bat ◽  
Auditory Systems ◽  
Species Specific ◽  
Output Constraint

Neuroethological investigations of mammalian and avian auditory systems have documented species-specific specializations for processing complex acoustic signals that could, if viewed in abstract terms, have an intriguing and striking relevance for human speech sound categorization and representation. Each species forms biologically relevant categories based on combinatorial analysis of information-bearing parameters within the complex input signal. This target article uses known neural models from the mustached bat and barn owl to develop, by analogy, a conceptualization of human processing of consonant plus vowel sequences that offers a partial solution to the noninvariance dilemma – the nontransparent relationship between the acoustic waveform and the phonetic segment. Critical input sound parameters used to establish species-specific categories in the mustached bat and barn owl exhibit high correlation and linearity due to physical laws. A cue long known to be relevant to the perception of stop place of articulation is the second formant (F2) transition. This article describes an empirical phenomenon – the locus equations – that describes the relationship between the F2 of a vowel and the F2 measured at the onset of a consonant-vowel (CV) transition. These variables, F2 onset and F2 vowel within a given place category, are consistently and robustly linearly correlated across diverse speakers and languages, and even under perturbation conditions as imposed by bite blocks. A functional role for this category-level extreme correlation and linearity (the “orderly output constraint”) is hypothesized based on the notion of an evolutionarily conserved auditory-processing strategy. High correlation and linearity between critical parameters in the speech signal that help to cue place of articulation categories might have evolved to satisfy a preadaptation by mammalian auditory systems for representing tightly correlated, linearly related components of acoustic signals.

scholarly journals Interspecific differences of stridulatory signals in three species of bark beetles from the genus Polygraphus Er. (Coleoptera: Curculionidae, Scolytinae) inhabiting the island of Sakhalin

2019 ◽  
Author(s):  
Ivan Andreevich Kerchev
Keyword(s):  
Host Plant ◽  
Plant Species ◽  
Bark Beetles ◽  
Acoustic Signals ◽  
Interval Number ◽  
Host Plant Species ◽  
Interspecific Differences ◽  
Species Specific ◽  
Conspecific Interactions

Stridulatory signals are involved in conspecific interactions between bark beetles (Coleoptera: Curculionidae, Scolytinae). In this study, we compared the qualitative profiles of acoustic signals in three species from the genus Polygraphus Er. Sympatry can be periodically observed in two of them – P. proximus and P. subopacus. Sporadically they occur on the same plants. P. nigrielytris colonize distinctly different host plant species; however, on the island of Sakhalin it inhabits the same biotopes. The purpose of the study is to identify species-specific parameters and the extent of differences in stridulatory signals of these species. Airborne signals produced during the contact of males of the same species were experimentally recorded. Among tested parameters of stridulatory signals, as the most species-specific were noted: chirp duration, interchirp interval, number of tooth-strikes per chirp, and intertooth-strike interval.

scholarly journals Male territorial vocalizations and responses are decoupled in an avian hybrid zone

2008 ◽  
Vol 363 (1505) ◽  
pp. 2879-2889 ◽  
Author(s):  
Paula M den Hartog ◽  
Hans Slabbekoorn ◽  
Carel ten Cate
Keyword(s):  
Hybrid Zone ◽  
Acoustic Signals ◽  
Hybrid Zones ◽  
Natural Hybrid ◽  
Individual Male ◽  
Individual Strategy ◽  
Intraspecific Communication ◽  
Selective Sensitivity ◽  
Species Specific ◽  
Male Signals

A core area of speciation research concerns the coevolution of species-specific signals and the selective sensitivity to such signals. Signals and responses to them should be tuned to each other, to be effective in intraspecific communication. Hybrid zones are ideal to study the presence of such ‘behavioural coupling’ and the mechanisms governing it, and this has rarely been done. Our study examines acoustic signals of males and their response to them in the context of territorial interactions in a natural hybrid zone between two dove species, Streptopelia vinacea and Streptopelia capicola . Male signals are important in hybrid zone dynamics as they are essential for territory establishment, which is crucial for successful reproduction. We tested whether the response of individual male hybrids is linked to how similar their own signal is to the playback signal. We did not find evidence for behavioural coupling. The combined evidence from the low level of response to hybrid and heterospecific signals outside the hybrid zone and a lack of coupling within the hybrid zone suggests that perceptual learning may explain our results. Learning to respond to locally abundant signals may be the best individual strategy and is likely to contribute to the maintenance of a hybrid zone.

Combat, display and ritualization in Fiddler Crabs (Ocypodidae, genus Uca )

1966 ◽  
Vol 251 (772) ◽  
pp. 459-472 ◽  
Keyword(s):  
Visual Display ◽  
Acoustic Signals ◽  
Point Of View ◽  
Fiddler Crabs ◽  
Evolutionary Origins ◽  
The Social ◽  
Serious Injury ◽  
Species Specific ◽  
Principal Elements ◽  
Major Cheliped

The principal elements of fighting and display in the genus Uca are surveyed from the point-of-view of their apparent evolutionary origins. The components include combat behaviour between males, threat postures, acoustic signals and visual displays. The latter are characterized by rhythmic motions of the large cheliped and other appendages. Combat between males is highly ritualized, with morphological and behavioural deterrents to maximum intensity. When the deterrents are effective the fights are usually without noticeable results. Although serious injury virtually never occurs, when the deterrents are inadequate the loser sometimes gives up his burrow and occasionally does not court for varying periods thereafter. Combat seems to have evolved directly from the decapod motion of grasping combined at low intensities with an appeasement element in which the major cheliped—a releaser of aggressive behaviour—is turned away from the opponent. Threat postures are primarily intention motions of fighting. Both in the burrows and occasionally on the surface stridulation and other acoustic signals are used in threat, courtship or both. Unlike combat behaviour and threat postures, visual display is species-specific. The twenty-odd elements most often occurring in both acoustic and visual display seem clearly to be derived chiefly from feeding, cleaning and threat movements, usually through the intermediary of displacement activities; sometimes the display elements apparently evolved from conflict between feeding and threat tendencies and sometimes from intention motions. Even in species with the most advanced displays, ritualization of some elements is often only partly or temporarily achieved, while the corresponding displacement motion, unaltered and uncomplicated, is frequently elicited. Parallelisms are evident between the courses of evolution in the social behaviour of fiddler crabs and vertebrates.

scholarly journals IDENTIFICATION OF ACOUSTIC SIGNATURES FOR VEHICLES VIA REDUCTION OF DIMENSIONALITY

2004 ◽  
Vol 02 (01) ◽  
pp. 1-22 ◽  
Author(s):  
AMIR AVERBUCH ◽  
EYAL HULATA ◽  
VALERY ZHELUDEV ◽  
INNA KOZLOV
Keyword(s):  
Frequency Domain ◽  
Acoustic Signal ◽  
Acoustic Signals ◽  
False Alarms ◽  
Reduction Of Dimensionality ◽  
Acoustic Signatures ◽  
Acoustic Signature ◽  
Moving Vehicles ◽  
Wide Range

In this paper we propose a robust algorithm that solves two related problems: (1) Classification of acoustic signals emitted by different moving vehicles. The recorded signals have to be identified to which pre-existing group they belong to independently of the recording surrounding conditions. (2) Detection of the presence of a vehicle in a certain class via analysis of its acoustic signature against the existing database of recorded and processed acoustic signals. To achieve this detection with minimal false alarms we construct the acoustic signature of a certain vehicle using the distribution of the energies among blocks which consist of coefficients of multiscale local cosine transform (LCT) applied in the frequency domain of the acoustic signal. The proposed algorithm is robust even under severe noise and diverse rough surrounding conditions. This is a generic technology, which has many algorithmic variations, can be used to solve wide range of classification and detection problems which are based on a unique derivation of signatures.

scholarly journals Key limitations of fish feeds, feed management practices, and opportunities in Kenya’s aquaculture enterprise

2021 ◽  
Vol 21 (02) ◽  
pp. 17415-17434
Author(s):  
Jonathan Munguti ◽  
◽  
K Obiero ◽  
H Odame ◽  
J Kirimi ◽  
...  
Keyword(s):  
Management Practices ◽  
Small Scale ◽  
Fish Feed ◽  
East African ◽  
African Region ◽  
Feed Quality ◽  
Feed Management ◽  
Fish Feeds ◽  
Species Specific ◽  
On Farm

Profitability is key in fish farming, just as it is to any other enterprise. For the farmers to actualize high-profit margins, it is imperative to have access to well-balanced nutritive and cost-effective feeds, backed by sound on-farm feed management practices. This paper auditsKenya’sfish feed industry and the on-going on-farm feed management practices, and emerging opportunities for fish farmers. The development of fish feed quality standards has boosted the aquaculture sector in Kenya, providing them hope that farmers will access high quality fish feeds. Much of the fish feed currently being used in Kenya is produced on-farm or by small-scale fish feed manufacturers within the East African region, while a few are imported directly from overseas countries, notably Israel, Netherlands, Mauritius and Denmark. Fish feeds produced by small-scale manufacturers are not closely monitored by quality standard agencies and not surprising that a majority are of poor quality. The improvement in the quality of these feeds is likely to lead to increased productivity and profitability because they are cheaper and readily available to fish farmers, compared to imported fish feeds. Besides feed quality, feed management practices markedly impact both the growth and economic performance of fish production. Adopting appropriate feed management strategies, therefore, is instrumental in the maximization of fish production and economic returns. Research has demonstrated several strategies for best feed management practices, which have not hitherto, been adopted by fish farmers in Kenya. Farmers have mainly focused on the mode of delivery of feeds to the fish. Furthermore, promoting natural pond productivity and supplementary feeding is still a common practice in the East African region. Provision of species-specific feeds and targeting the nutritional requirements of the different life stages of fish is still a major issue, although some local companies like Unga Farm Care(EA)have come up with a size and species-specific feed for catfish such as Fugro catfish®.To improve access to such information,public-private partnerships should be developed and, programmes that utilize the local media platforms such as extension service outlets must also be encouraged. Feed quality checks can also be carried out amongst fish feed suppliers. Lastly, farmers should be trained in various fish feed aspects like formulation, transportation and storage to sustain a steady fishfeed supply andsave on associated feed costs.

scholarly journals Interspecific differences of stridulatory signals in three species of bark beetles from the genus Polygraphus Er. (Coleoptera: Curculionidae, Scolytinae) inhabiting the island of Sakhalin

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8281
Author(s):  
Ivan Andreevich Kerchev
Keyword(s):  
Host Plant ◽  
Plant Species ◽  
Bark Beetles ◽  
Acoustic Signals ◽  
Host Plant Species ◽  
Interspecific Differences ◽  
Species Specific ◽  
Conspecific Interactions

Stridulatory signals are involved in conspecific interactions between bark beetles (Coleoptera: Curculionidae, Scolytinae). In this study, we compared the qualitative profiles of acoustic signals in three species from the genus Polygraphus Er. Sympatry can be periodically observed in two of them –P. proximus and P. subopacus. Sporadically they occur on the same plants. P. nigrielytris colonize distinctly different host plant species; however, on the island of Sakhalin it inhabits the same biotopes. The purpose of the study is to identify species-specific parameters and the extent of differences in stridulatory signals of these species. Airborne signals produced during the contact of males of the same species were experimentally recorded. Among tested parameters of stridulatory signals, as the most species-specific were noted: chirp duration, number of tooth-strikes per chirp, and intertooth-strike interval.

Evolution of Cranial and Endocranial Profiles inHomoSpecies: a Study in 2D Geometric Morphometrics

2016 ◽  
Vol 28 (3-4) ◽  
pp. 118-131
Author(s):  
L. Albessard ◽  
D. Grimaud-Hervé ◽  
A. Balzeau
Keyword(s):  
Geometric Morphometrics ◽  
Homo Sapiens ◽  
Brain Structures ◽  
Homo Erectus ◽  
Human Cognition ◽  
Cranial Bone ◽  
Cranial Morphology ◽  
Anatomical Features ◽  
Homo Neanderthalensis ◽  
Object Of Study

Cranial anatomical features play a prominent part in the definition of extinctHomotaxa and in species identification in fossils. Thus, knowledge of cranial morphology considered within its geochronological framework is essential to the understanding of the evolution, chronology, and dispersal of the genusHomo. The brain is also a valuable object of study for research on human evolution, because of features such as its large size and a high encephalization quotient in someHomospecies, as well as the complexity of human cognition. However, the joint evolution of endo- and ectocranial anatomies is still little studied, and landmarks representing cerebral anatomy rather than inner cranial bone anatomy are still rarely used. This exploratory piece of research examines endo- and ectocranial profiles in samples representing 3Homotaxa:Homo sapiens(fossil and recent specimens),Homo erectus, andHomo neanderthalensis. We used 2D geometric morphometrics to analyze the shape of the endo- and ectocranial vaults, as well as the relationships between selected anatomical features such as the extension of lobes and bones. The shapes of the vaults were computed using both fixed landmarks and sliding semi-landmarks. The fixed landmarks used for the endocranium were chosen in order to represent cerebral anatomy, in that they are defined by the imprints left by brain structures on the inner bone surface of the skull, and not by bony structures such as the inferior side of cranial sutures. Among other results, we have shown or confirmed specific features in the shape of the endocranium inHomo sapiens, as well as a few differences in the patterns of interplay between lobes and bones. These data, and any further results obtained with larger samples, may provide new insights into the development of the endocranial anatomical pattern inHomo sapiensand of its variability.

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