Acoustic behavior of the damselfish Dascyllus albisella: behavioral and geographic variation

Behavioral and geographic variation in animal communication has been well-studied in insects, frogs, birds, and mammals, but little is known about variation in fishes. We used underwater audio-video recordings of the behavior and associated sounds produced by the domino damselfish, Dascyllus albisella, at Johnston Atoll and Hawaii, which are separated by 1000 km, to study behavioral and geographic variation in communication sounds. Males produced pulsed sounds during the courtship behavior known as the signal jump, visiting by females (during pseudospawning), mating, aggression to heterospecifics and conspecifics, and nest preparation. Females made only aggressive sounds. The following features of the sounds were measured: number of pulses, pulse rate, pulse duration, inter-pulse interval, dominant frequency, and frequency envelope. The only difference between visiting and mating sounds was a small difference in pulse duration. Two types of aggressive sounds were produced, pops and chirps. Pops contained only one or two pulses and were more commonly made towards heterospecifics than conspecifics. Aggressive chirps had between 3–11 pulses and were made most often towards conspecifics. The pulse rate of aggressive chirps was faster than signal jump sounds. The only difference in signal jump sounds made by males from Johnston Atoll and Hawaii, was a small difference in pulse duration, which was likely due to differences in the depths of the recording environment and not in the sounds produced.     

Comparative trophic morphology in eight species of damselfishes (Pomacentridae)

Damselfishes show significant biodiversity in the coral reefs. To better understand such diversity, an ecomorphological approach was investigated in the trophic morphology of eight species of Pomacentridae (Chromis acares, C. margaritifer, Dascyllus aruanus, D. flavicaudus, Pomacentrus pavo, Plectroglyphidodon johnstonianus, Pl. lacrymatus and Stegastes nigricans) belonging to different trophic guilds (zooplankton, algal, coral polyp feeders and omnivores). Geometric morphometrics were used to quantify size and shape variations in four skeletal units: (1) neurocranium, (2) suspensorium and opercle, (3) mandible and (4) premaxilla. This method allowed us to reveal shape and size differences correlated to functional diversity both within and between trophic guilds. Among zooplanktivores, C. margaritifer, D. aruanus and D. flavicaudus have a high and long supraoccipital crest, short mandibles forming a small mouth and high suspensoria and opercles. These three species can be considered to be suction feeders. In the same guild, C. acares shows opposite characteristics (long and thin mandibles, lengthened neurocranium and suspensorium) and can be considered as a ram feeder. Among herbivores and corallivores, the two species of Plectroglyphidodon and S. nigricans can be considered as grazers. Differences in skeletal shape are mainly related to improving the robustness of some skeletal parts (broad hyomandibular, short and high mandibles). The shapes of P. pavo, which feeds largely on algae, strongly differ from that of the other three grazers exhibiting similar morphological characteristics to C. acares (e.g., long and shallow suspensorium, lengthened neurocranium). This highlights likely differences concerning cutting or scraping method. Finally, no strong correlations exist between size and shapes in the eight studied species. Size difference among species having a very similar shape could be viewed as a factor optimizing resource partitioning.     

The structure and function of songs emitted by southern green stink bugs from Brazil, Florida, Italy and Slovenia

Nezara viridula (L.) (Pentatomidae: Heteroptera) from Brazil, Florida, Italy and Slovenia, communicate by vibratory songs associated with long‐range calling and close‐range courting, rivalry and repelling. Each song is composed of spectrally and temporally different units. Spectrally different pulses of duration less than 300 ms are present in the male calling song. The female calling song is characterized by pulse trains composed of pulses shorter than 150 ms and pulse trains composed of a longer (> 700 ms) and shorter (< 250 ms) pulse. Shorter and longer pulses have different spectral characteristics. The male and female courtship songs are characterized by fusion of shorter (< 150 ms) pulses into a pulse train usually followed by a shorter (< 200 ms) postpulse in the case of the male courtship song. The female repelling song is a several seconds long vibration of irregular temporal structure. The short (< 400 ms) male rival song pulses are frequency modulated. The dominant frequency peaks of the songs investigated lie between 70 and 130 Hz. The dominant frequency and the microstructure of song spectra show no population specificity. The average duration varies more in calling than in courtship songs. The repetition time varies extensively in songs of different populations. Normal communication followed by copulation was observed between mates from Slovenia and Brazil and between mates from Florida and Italy. The potential role of different temporal and spectral parameters for species recognition and mate location is discussed in view of the expected distortion of the characteristic signal structure during transmission through plants.     

Sound production in four damselfish (Dascyllus) species: phyletic relationships?

Most studies of fish sounds show that the sounds are species-specific, with unique spectral and timing characteristics. This raises the question as to whether these sounds can be used to understand phyletic relationships between species and which acoustic parameters are subject to variation between species. In the present study, 597 sounds (and 2540 pulses) related to signal jumps of four Dascyllus species ( Dascyllus aruanus , Dascyllus trimaculatus , Dascyllus albisella , and Dascyllus flavicaudus ) from different geographic regions (Madagascar, Moorea, Rangiroa, and Hawaii) were analysed. It was possible to discern species-specific sounds, but also variation in sounds between populations. Large variations in sound length were found between Dascyllus species, whereas differences in interpulse duration were found to be variable between populations. In the regions where species live in sympatry, it appears that they restrict the variability in their sounds. This could comprise evidence of adaptation with character displacement of sonic characteristics where different species co-occur. However, sonic characteristics still overlapped substantially between species, suggesting that females would need to sample more than one sound and potentially use other cues to discriminate between species.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 97 , 928–940.     

CHARACTERISTICS OF MINKE WHALE (BALAENOPTERA ACUTOROSTRATA) PULSE TRAINS RECORDED NEAR PUERTO RICO

A nine-day acoustic and visual survey was conducted off the West Indies in March 1994 to study the pulse trains that were detected on SOSUS arrays throughout winter in deep water between the West Indies and Bermuda. During the survey, pulse train sounds were consistently recorded in an area 190–350 km northeast of Puerto Rico. Vocalizing animals were never visually observed, but visual sighting conditions were often poor and observation height was low. Pulse trains occurred in two basic forms. The "speed-up" pulse train was characterized by an accelerating series of pulses with energy in the 200–400 Hz band, with individual pulses lasting 40-60 msec. Speedup pulse trains started with average pulse rates of 1.5 pulses/sec, lasted 43.7 ± 6.0 sec, and ended with average pulse rates of 2.8 pulses/sec. The less common "slow-down" pulse train was characterized by a decelerating series of pulses with energy in the 250-350 Hz band. Slow-down pulse trains started at pulse rates averaging 4.5 pulses/sec, lasted 60.9 ± 5.8 sec, and ended with average pulse rates of 2.9 pulses/sec. We believe the recorded pulse trains are from minke whales based on careful reanalysis of, and comparison to, minke whale pulse-train sounds recorded in the Caribbean by Winn and Perkins (1976).     

Isolation and characterization of 16 microsatellite loci in the humbug damselfish, Dascyllus aruanus (family Pomacentridae)

Here we report on 16 microsatellite loci designed for the damselfish Dascyllus aruanus. All loci were tested on 98 individuals and were polymorphic (seven to 35 alleles). Expected heterozygosity ranged from 0.705 to 0.942. Six loci showed Hardy-Weinberg disequilibrium due to the occurrence of null alleles. Cross-species amplifications conducted within the genus Dascyllus (D. carneus, D. strasburgi, D. trimaculatus) lead to polymorphic fragments in 32 out of 48 tests. These 16 loci will enable future research into the behavioural ecology and population ecology of Dascyllus aruanus throughout the Indo-Pacific.     

Biosociology and ecology of pomacentrid fishes around the Sinai Peninsula (northern Red Sea)

Pomacentrid fishes inhabiting the coral formations along the Red Sea coast of Sinai Peninsula form specific groups of species on various habitats. Amphirion bicinctus, Dascyllus aruanus, D. marginatus and Pomacentrus trichourus are typical for the backreef lagoon; Pomacentrus sulfureus, Abudefduf melanopus and A. melas are common along the rearreef wall; Pomacentrus albicaudatus, P. tripunctatus, Abudefduf lacrymatus, A. leucozona and A. annulatus dominate the coral reef table. The forereef wall is occupied by Abudefduf saxatilis, A. sexfasciatus and A. leucogaster . The lower part of the forereef and coral knolls along it are inhabited by groups of Abudefduf azysron, Chromis dimidiatus, C. caeruleus, C. ternatensis and of the Dascyllus trimaculatus . Among the fishes observed a part are living in groups or schools, whereas others are typical solitary, permanent territory holders. Most of them are polygamous, breeding in colonies, or solitary in nests, guarded by males. The variation in feeding behaviour as well as in sociobiology, enables the high diversity of these fishes on various parts of the habitat.     

The Hemiuroidea (Digenea) of pomacentrid fishes (Perciformes) from Heron Island,Queensland, Australia

The following species are described, figured and/or recorded from pomacentrid fishes from the vicinity of the southern Great Barrier Reef coral cay Heron Island, with some mention of comparative material from other host families and locations: Derogenes pearsoni n. sp. from Amblyglyphidodon curacao, Amphiprion akindynos, Plectroglyphidodon lacrymatus (type-host), Pomacentrus chrysurus, P. moluccensis, P. tripunctatus and Pomacentrus sp.; Derogenes pharyngicola n. sp. from Abudefduf whitleyi (type-host) and Plectroglyphidodon dickii; Lecithaster stellatus from Abudefduf sexfasciatus, A. whitleyi, Acanthochromis polyacanthus, Amblyglyphidodon curacao, Chrysiptera flavipinnis, Parma polylepis, Pomacentrus chrysurus, P. moluccensis, P. cf. nagasakiensis, P. cf. pavo, P. vaiuli, P. wardi, Seriola lalandi, Cheilinus diagrammus, Lethrinus miniatus and Choerodon cyanodus from Heron Island plus Acanthopagrus australis and Rhabdosargus sarba from Moreton Bay; Aponurus laguncula from Pomacentrus moluccensis plus Callionymus limiceps, Platycephalus endrachtensis and P. fuscus from Moreton Bay; Hysterolecitha nahaensis from Abudefduf bengalensis, A. sexfasciatus, A. whitleyi, Acanthochromis polyacanthus, Amblyglyphidodon curacao, A. leucogaster, Amphiprion akindynos, A. perideraion, Chromis atripectoralis, C. nitida, C. viridis, Chrysiptera flavipinnis, C. cf. rollandi, Dascyllus aruanus, D. reticulatus, Parma polylepis, Pomacentrus chrysurus, P. moluccensis, P. cf. nagasakiensis, P. nigromarginatus, P. cf. pavo, P. tripunctatus, P. wardi and Pomacentrus sp.; Hysterolecitha heronensis n. sp. from Pomacentrus philippinus (type-host), P. amboinensis, P. moluccensis, P. nigromarginatus and Pomacentrus sp.; Hysterolecitha sp. innom. from Parma polylepis; Thulinia microrchis n. comb. (new syns Hysterolecitha microrchis, H. xesuri, H. tinkeri, Thulinia tinkeri, H. sigani) from Abudefduf bengalensis, A. sexfasciatus, A. whitleyi, Acanthochromis polyacanthus, Amphiprion perideraion, Dascyllus aruanus, D. reticulatus, Dischistodus melanotus, Parma polylepis, Plectroglyphidodon dickii, Pomacentrus amboinensis, P. moluccensis, P. philippinus, P. taeniometopon, Pomacentrus sp. and Stegastes apicalis, plus Chaetodon citrinellus, C. kleinii, Chaetodontoplus meredithi, Lethrinus miniatus, Plectropomus leopardus, Siganus doliatus, S. lineatus and S. vulpinus; Leclthocladium sp. juv from Abudefduf whitleyi, Lecithochirium sp. (? ghanense-group) from Dascyllus aruanus; Lecithochirium sp. juv. from Abudefduf whitleyi; unidentified non-ecsomate hemiuroids from Chrysiptera cf. rollandi, Parma polylepis, Pomacentrus chrysurus, P. wardi and Stegastes apicalis.     

Sound production by the Shi drum Umbrina cirrosa and comparison with the brown meagre Sciaena umbra: a passive acoustic monitoring perspective

Sounds produced by the Shi drum Umbrina cirrosa were short trains of pulses with an average pulse period of 180 ms, pulse duration of c. 40 ms and an average peak frequency of 400 Hz; average values of acoustical properties differed from those recorded from the brown meagre Sciaena umbra in previous studies. The present study provides a preliminary tool for discriminating between these two species while conducting passive acoustic monitoring. The potential effects of ontogeny on sound production in both species are discussed and recommendations are made for further research.     

Passive acoustic monitoring,development of disturbance calls and differentiation of disturbance and advertisement calls in the Argentine croaker Umbrina canosai (Sciaenidae)

Disturbance and advertisement calls of the Argentine croaker Umbrina canosai were recorded from coastal Uruguayan waters. Dissections indicate typical sciaenid extrinsic swimbladder muscles present exclusively in males. Disturbance calls were produced when captive U. canosai were startled, chased with a net or grabbed by the tail. Calls were unusual for sciaenids because each pulse consisted of multiple cycles. The number of cycles per pulse and dominant frequency did not change with U. canosai size, but pulse duration and interpulse interval increased. Advertisement calls were recorded from unseen choruses in the field and confirmed with captive individuals in a large tank. Advertisement calls were recorded throughout the known range of the species in Uruguay indicating a continuous belt of spawning populations. Tank recordings of the same individuals permitted explicit comparisons between the two calls. Advertisement call pulses averaged 2·4 more cycles (11·0–8·6) although pulses of both calls were basically similar as were durations and dominant frequencies. Pulse number, however, differed markedly, averaging 13·6 and 3·4 pulses for disturbance and advertisement calls respectively. Furthermore, disturbance calls were produced as a rapid series with an interpulse interval of 26–31 ms whereas advertisement call patterns were less stereotyped and ranged from <100 to 450 ms. Multicycle pulses distinguished U. canosai from other sympatric sciaenids.     

Mouse Postganglionic Sympathetic Neurons

Basic properties of noradrenaline release were studied in primary cultures of thoracolumbar postganglionic sympathetic neurons taken from 1-3-day-old NMRI mice. After 7 days in vitro, the cultures were preincubated with [3H]noradrenaline and then superfused and stimulated electrically. Conventional trains of pulses (for example, 36 pulses at 3 Hz) as well as single pulses and brief high-frequency trains (for example, four pulses at 100 Hz) elicited a well-measurable overflow of tritium, which was abolished by 0.3 microM tetrodotoxin or omission of Ca2+, but not changed by 1 microM rauwolscine. In trains of one, two, four, six, eight, or 10 pulses at 3 Hz, the evoked overflow of tritium remained constant from pulse to pulse at 1.3 mM Ca2+, but declined slightly at 2.5 mM Ca2+. Tetraethylammonium at 10 mM selectively increased the overflow elicited by small pulse numbers and especially by a single pulse. In trains of 10 pulses delivered at 0.3, 1, 3, 10, 30, or 100 Hz, the evoked overflow of tritium increased from 0.3 to 30 Hz and then declined at 100 Hz. This relationship was particularly pronounced at low Ca2+ concentrations (for example, 0.3 mM). Tetraethylammonium at 10 mM selectively increased the overflow elicited by low frequencies of stimulation. It is concluded that primary cultures of mouse postganglionic sympathetic neurons can be used to investigate release of [3H]noradrenaline. The release is well measurable, even upon a single electrical pulse. It agrees with release in intact sympathetically innervated tissues in a number of fundamental properties, including the pulse number and frequency dependence. The preparation may be of special interest in conjunction with genetic manipulations in the donor animals.     

Possible species specific courtship sounds by two sympatric cichlid fishes in Lake Malawi, Africa

Sounds were produced by the males of two species of cichlid fishes while courting females. Each courtship sound consisted of a series of distinct pulses occurring in rapid succession. Courtship sounds produced by Tramitichromis cf. intermedius and Copadichromis conophorus were significantly different in pulse rate and individual pulse durations. For C. conophorus calls (n=127) the mean ± sd number of pulses per call was 10 ± 3 and call duration was 181 ± 59 ms. There was a significant positive linear relationship between call duration and the number of pulses (r²=0.912, p < 0.001). The dominant frequency of the pulses in calls was 471 ± 50 (range 372–594) Hz (n=40 calls). T. cf. intermedius also produced a pulsed courtship call; data (mean ± sd) from two male T. cf. intermedius: 9 ± 2 pulses per call and duration 199 ± 44 ms (n=20 calls). The linear regression between call duration and number of pulses was positive (r²=0.463, p=0.001). Pulse rate within calls of T. cf. intermedius compared to C. conophorus were significantly different (p=0.018). Individual pulse durations were also significantly different (p=0.043) between species. However, interpulse intervals were not significantly different (p=0.177). These cichlids produced courtship sounds that were distinct by individual pulse durations and by pulse repition rate in a call.     

Rate and Duration of Stimulation Determine Presynaptic Effects of Haloperidol on Dopaminergic Neurons

Abstract: Superfused rabbit neostriatal slices prelabeled with [³H]dopamine ([³H]DA) were depolarized with electrical pulses (12 V, 1 ms). Although transmitter release showed a proportional increase with a greater number of pulses (30-360 pulses), flat frequency-release curves were obtained. Haloperidol (0.03–0.3 μ m ) enhanced ³H overflow without affecting its metabolism or time course, and antagonized apomorphine-induced inhibition of transmitter release. Maximal enhancement of release by haloperidol was obtained with 30–60 pulses delivered at a rate of 3 Hz, whereas much less facilitation of release was seen at 0.3 and 1 Hz (30–90 pulses) or with 360 pulses at either of the three frequencies. Therefore, the slope of the frequency-release curve was markedly increased by haloperidol. These results indicate that activation of presynaptic DA receptors, and thus facilitation of release by haloperidol was highly dependent on the rate and duration of stimulation of striatal dopaminergic terminals. In these neurons the feedback loop seems to act physiologically to depress the slope of the frequency-release curve.     

Sound production by the river bullhead, Cottus gobio L. (Cottidae, Teleostei)

Acoustic signals of Cottus gobio consist of knocking sounds produced as single pulses (48 ms) or as trains of 4–6 pulses (230 ms). Frequencies extend up to 3 kHz, but most sound energy is concentrated between 50 and 500 Hz in both sound types. Cottus gobio is solitary, maintains territories, and defends them by threat display, seldom by biting and fighting. Threatening consists of spreading gill covers and fins, darkening, and sound production. Calling is accompanied by a nodding movement of the head, during which the pectoral girdle and the skull are moved rapidly against each other. No difference in ability of sound production was observed between sexes, but males emitted significantly more sounds than females. In the laboratory an increase in vocalization activity was observed between night and day. An increase in the number of encounters and calls was noted when temperatures were raised from 8°C to 13°C. Sound production was registered throughout the year.     

Behavioral response ofGraminella nigrifrons (Homoptera: Cicadellidae) to experimentally manipulated vibrational signals

Mate recognition for the leafhopper Graminella nigrifrons(Forbes) occurs when a male spontaneously emits a multisectional vibrational calling song to which females respond by emitting simple pulses. Significant differences were found among males in the duration, number of chirps, and chirp rate within sections of the song and the total song. Repeatability (proportion of total variation due to differences among males) of call features ranged from very low (0.04 for total chirps in song) to high (0.67 for section 3 chirp rate). However, song modification and playback experiments revealed that the variation in the measured song features was not important in determining whether a female will respond. Rather, female response depended only on the presence of two of the three types of pulses which comprise a chirp. These essential pulses were found within chirps of all call sections that contain chirps. Manipulation of chirp rates from 0.58 to 2.70 times the normal rate did not affect female response, nor did changing the period of silence between the essential pulse types from 0.25 to 1.75 times the normal period. These results suggest that components of the male calling song function in mate recognition but are not used by females to discriminate among conspecific males.     

The damselfishes (Pisces: Osteichthyes: Pomacentridae) of Peninsular Malaysia and Singapore: systematics,ecology and conservation

Damselfishes (Pomacentridae) are among the most common of reef fishes in tropical seas, comprising 320 species in all, with 268 species alone in the Indo-West Pacific regions. 15 genera (Abudefduf, Amblyglyphidodon, Amphiprion, Chelioprion, Chromis, Chrysiptera, Dascyllus, Pristotis, Dischistodus, Hemiglyphidodon, Neoglyphidodon, Neopomacentrus, Plectroglyphidodon, Pomacentrus, Stegastes) and at least 39 species inhabit the waters of Peninsular Malaysia and Singapore. They are important ecologically because many species are extremely abundant in reefs, and also economically, as several are collected in large numbers for the lucrative aquarium trade. This demand has led to some fishermen using destructive methods in obtaining the fishes, to the point that original standing populations may not be recoverable. This threat poses a need for conservation of the reefs. The present study based primarily on fishes collected from the waters of Singapore and specimens from the Zoological Reference Collection at the National University of Singapore, will serve the dual purpose of establishing a current species list for Malaysia and Singapore, and to update and clarify the local taxonomy of the group. An annotated list (with localities) is provided of the known or reported species to aid studies on reefs.     

Courtship and spawning sounds in bird wrasse Gomphosus varius and saddle wrasse Thalassoma duperrey

Acoustic signals from the bird wrasse Gomphosus varius and saddle wrasse Thalassoma duperrey were recorded on coral reefs in Hawaii. Terminal phase males in both species emit two types of pulse trains (type I and type II). Type I pulses were produced during spawning and courtship, while type II pulses were associated only with courtship behaviours. Gomphosus varius type I pulses were of lower frequency than T. duperrey type I pulses (271 v. 840 Hz) and were of narrower band. Discriminant function analyses revealed interspecific differences between type I pulse trains and individual pulses of both types. This study is the first documentation of courtship and spawning sounds in sympatric labrids and shows divergence in acoustic signals.     

Acoustic communication in Okanagana rimosa (Say) (Homoptera: Cicadidae)

The cicada Okanagana rimosa (Say) has an acoustic communication system with three types of loud timbal sounds: (i) A calling song lasting several seconds to about 1 min which consists of a sequence of chirps at a repetition rate of 83 chirps per second. Each chirp of about 6 ms duration contains 4-5 pulses. The sound level of the calling song is 87-90 dB SPL at a distance of 15 cm. (ii) An amplitude modulated courtship song with increasing amplitude and repetition rate of chirps and pulses. (iii) A protest squawk with irregular chirp and pulse structure. The spectra of all three types are similar and show main energy peaks at 8-10 kHz. Only males sing, and calling song production is influenced by the songs of other males, resulting in an almost continuous sound in dense populations. In such populations, the calling songs overlap and the temporal structure of individual songs is obscured within the habitat. The calling song of the broadly sympatric, closely related species O. canadensis (Provander) is similar in frequency content, but distinct in the temporal pattern (24 chirps per second, 24 ms chirp duration, eight pulses per chirp) which is likely important for species separation in sympatric populations. The hearing threshold of the auditory nerve is similar for females and males of O. rimosa and most sensitive at 4-5 kHz. Experiments in the field show that female phonotaxis of O. rimosa depends on parameters of the calling song. Most females are attracted to calling song models with a 9 kHz carrier frequency (peak frequency of the calling song), but not to models with a 5 kHz carrier frequency (minimum hearing threshold). Phonotaxis depends on temporal parameters of the conspecific song, especially chirp repetition rate. Calling song production is influenced by environmental factors, and likelihood to sing increases with temperature and brightness of the sky. Correspondingly, females perform phonotaxis most often during sunny conditions with temperatures above 22 degrees C. Non-mated and mated females are attracted by the acoustic signals, and the percentage of mated females performing phonotaxis increases during the season.     

Calling song signals and temporal preference functions in the cricket Teleogryllus leo

The acoustic display of many cricket species consists of trains of pulses (chirps) with intermittent pauses. Here, we investigated the temporal cues that females of the cricket Teleogryllus leo used to detect a pulse and a chirp pattern on two different time scales. For both patterns, females accepted a wide range of combinations that covered the respective pulse and chirp parameters in the songs of males. In tests with a continuous series of pulses at different modulation frequencies, the transfer function of pattern discrimination was also determined. Females exhibited two ranges of high response scores indicating two temporal filters with an inhibitory interaction. For the modulation frequency of the pulse pattern, the peak of the preference function was rather sharply tuned and at a lower pulse rate than produced by males. These results show that the combined output of both filters did not increase selectivity, but rather enlarged the accepted range of signals.     

Mathematical models for fatigue minimization during functional electrical stimulation

We previously reported the development of a force- and fatigue-model system that predicted accurately forces during repetitive fatiguing activation of human skeletal muscles using brief duration (six-pulse) stimulation trains. The model system was tested in the present study using force responses produced by longer duration stimulation trains, containing up to 50 pulses. Our results showed that our model successfully predicted the peak forces produced when the muscle was repetitively activated with stimulation trains of frequencies ranging from 20 to 40 Hz, train durations ranging from 0.5 to 1 s, and varied pulse patterns. The predicted peak forces throughout each protocol matched the experimental peak forces with r² values above 0.9 and predicted successfully the forces at the end of each protocol with <15% error for all protocols tested. The success of our model system further supports its potential use for the design of optimal stimulation patterns for individual users during functional electrical stimulation.