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Topic: Apteronotus albifrons

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	Journal Abstract (Site not responding. Last check: 2007-10-20)
		In Apteronotus leptorhynchus, chirps are usually rapid (10-30 ms) modulations that are activated through non- N-methyl- d-aspartate (non-NMDA) glutamate receptors in the hindbrain pacemaker nucleus.
		In Apteronotus albifrons, chirp rate is sexually monomorphic, but chirp structure (change in frequency and amplitude during a chirp) was unknown.
		However, unlike in A. leptorhynchus, chirp types in A. albifrons varied little in duration, and chirps were all longer (70-200 ms) than those of A. leptorhynchus.
	www.trincoll.edu /~kdunlap/abstracts/electrocommunication.html (230 words)

	Conclusions
		Although they are closely related, the species in Apteronotus have a neurogenically powered electric organ, and produce a frequency as a firing of neurons, while the fish in genus Eigenmannia have a myogenically powered weakly electric organ, producing a frequency by their muscle contractions.
		Therefore, during the actual JAR tests, it was the tendency to return to the original frequency that pulled the fish stronger than the tendency of the function generator to cause the fish to avoid jamming and move away from the generator.
		Both Apteronotus moved away from their original frequencies after the 4.5-hour tests, suggesting prolonged jamming response by further separating the fish’s frequency from the frequency that the fish was exposed to, and further moving from the original frequency.
	www.sidwell.edu /us/science/vlb5/Independent_Research_Projects/jgoodstein/Conclusions/body_conclusions.html (5487 words)

	Apteronotus leptorhynchus
		Ghost knifefish : The Black ghost knifefish (Apteronotus albifrons) and Brown ghost knifefish (Apteronotus leptorhynchus) are readily available as aquarium fish.
		Apteronotus :...valid as) Apteronotus leptorhynchus Ortega and Vari, 1986 Sternarchus leptorhynchus Ellis, 1912; (valid as) Apteronotus macrostomus...
		Aquarium breeding of the gymnotiforms Apteronotus albifrons, Apteronotus leptorhynchus, and Rhamphichthys sp.
	www.specieslist.com /fish_species/A/Apteronotus_leptorhynchus.shtml (1748 words)

	Weakly Electric Fish
		The Apteronotus (we only had one because the other died so early on) attacked anything that we put into the tank, including a thermometer one day.
		It voraciously attacked the food we fed it and constantly swam as though it was predating on enemies in the tank.
		She swam in all directions and was almost as active as the Apteronotus.
	www.sidwell.edu /us/science/vlb6/projects/brobinson/observations.html (775 words)

	Apteronotus albifrons
		Apteronotus : Apteronotus albifrons Ortega and Vari, 1986 Apteronotus lacepedii; (synonym) Apteronotus maximilliani; (synonym) Gymnotus albifrons Linnaeus, 1766; (valid as...
		akva.sk : Apteronotus albifrons (Linnaeus, 1758) - NoÅ¾ovec bielochvostÃ½ Rod: Actinopterygii Apteronotus ÄeÄ¾aÄ?: Apteronotidae SynonymÃ¡: Gymnotus albifrons...
		Apteronotus Albifrons, Pesce sud americano con abitudini crepuscolari Ã¨ facile vederlo alla sera.
	www.specieslist.com /fish_species/A/Apteronotus_albifrons.shtml (1664 words)

	Ghost knifefish - Wikipedia, the free encyclopedia
		They are distinguished from other gymnotiform fish by the presence of a caudal fin, and can be found in the neotropical regions of South America.
		The Black ghost knifefish (Apteronotus albifrons) and Brown ghost knifefish (Apteronotus leptorhynchus) are readily available as aquarium fish.
		A number of additional species have been discovered recently, and many more are expected to be found.
	en.wikipedia.org /wiki/Ghost_knifefish (95 words)

	Effect of external carbon dioxide concentration on the electric organ discharge frequency in the gymnotiform fish ... (Site not responding. Last check: 2007-10-20)
		A model is described for the instantaneous frequency (F) of electric organ discharge in Apteronotus albifrons: F = H/(aH + b), where a and b are linear parameters and H,hydrogen ion concentration.
		The frequency of the electric organ discharge (EOD) by Apteronotus albifrons as well as by all Gymnotiforms has long been considered to be so regular that it may be affected only by temperature, among other physicochemical factors of the aquatic medium (1-3).
		Acute increased extemal CO levels momentarily lead ta CO levels near 30 mg/l, pH 4.8, in water in spite of air bubbling and stirring (15-16), and had immediate repercussions on the blood system of the fish owing to great CO absorption, in spite of a small fall in blood pH (4).
	www.icb.ufmg.br /lpf/1-25.html (1921 words)

	FAMILIES - Detail (Site not responding. Last check: 2007-10-20)
		The Apteronotidae is confined to the Humid Neotropics, ranging the Rio de la Plata of Argentina (35° S) to the Rio Tuira of Panama (8°N).
		Apteronotus species are the most widely distributed, extending the full range of the family.
		Apteronotus species inhabit both floodplain and tierra firme (non-floodplain) streams and rivers.
	www.fishbase.org /Summary/FamilySummary.cfm?ID=545 (613 words)

	Electric Fish: QuickTime Movies
		If your computer is fast enough to show them at their programmed frame rate, then the Apteronotus leptorhynchus potential movie is shown at 1/4000 the actual EOD rate; A.
		An electric fish was immobilized and placed in the center of the fish tank on a respirator.
		This young A. albifrons has a surprisingly similar EOD pattern as the larger A. leptorhynchus.
	alumnus.caltech.edu /~rasnow/qtmov.html (883 words)

	Weakly Electric Fish
		Finally, our purpose is to study the behavior of the Eigenmannia virescens, Apteronotus albifrons, Gymnarchus niloticus, and Gnathonemus petersii.
		Hypothesis: The Apteronotus albifrons and the Gymnarchus niloticus, which are the least social fish, will consistently change less when exposed to jamming.
		Not only will both of these species consistently change less, but will also be the quickest to revert to their original frequency since they are not social fish.
	www.sidwell.edu /us/science/vlb6/projects/brobinson/experiment.html (962 words)

	Journal Abstract (Site not responding. Last check: 2007-10-20)
		We report that two congeneric species (Apteronotus leptorhynchus and A. albifrons) differ in the expression of sexual dimorphism in these signals.
		Corresponding to this difference in dimorphism, A. leptorhynchus increases chirping in response to androgens, but chirping in A. albifrons is insensitive to implants of testosterone, dihydrotestosterone or 11-ketotestosterone.
		Thus, in both chirping and electric organ discharge frequency, evolutionary changes in the presence or direction of sexual dimorphism have been accompanied and perhaps caused by changes in the androgen regulation of the electric organ discharge.
	www.trincoll.edu /~kdunlap/abstracts/diversity.html (239 words)

	Electrolocation
		The mechanisms of electrolocation are similar in all electric fish, but we illustrate the principles in Apteronotus albifrons (fl ghost knifefish), the fish that we study in the lab.
		Since Apteronotus has a wave-type electric organ discharge (EOD), the potential at any point in space is constantly changing.
		The body of Apteronotus is covered with approximately 15,000 specialized tuberous electoreceptor organs for detecting perturbations in it's own electric field.
	nelson.beckman.uiuc.edu /electrolocation.html (593 words)

	MSP Poster: Electric Fish (Site not responding. Last check: 2007-10-20)
		Black ghost knifefish (Apteronotus albifrons) are remarkably agile swimmers.
		This discharge is known as the Electric Organ Discharge (EOD) and in albifrons is around 1200 Hz.
		This phenomena of spinal cord regeneration in Apteronotus is actively being researched because most animals (including humans) do not have this ability.
	soma.npa.uiuc.edu /labs/nelson/msp_poster_www/electric_fish.html (208 words)

	Untitled Document (Site not responding. Last check: 2007-10-20)
		The Black Ghost Knife fish (Apteronotus albifrons) is a wave producing fish, while the Elephant Nose fish (Gnathonemus petersii) produces pulses (von der Emde 1999).
		Sternopygus macrurus EOD frequencies range between 50 and 150 hz, Eigenmannia virescens frequencies average 240 to 580 hz, and Apteronotus albifrons frequencies are even higher- 750-1250 hz (Hopkins 1972).
		Aggression: Studies with the Brown Ghost Knifefish Apteronotus leptorynchus have shown that their aggressive behavior is expressed by varying the duration of their EODs.
	www.bio.davidson.edu /biology/midorcas/animalphysiology/websites/2003/Wilson/Communication.htm (906 words)

	MSP Poster: Treatments (Site not responding. Last check: 2007-10-20)
		Since it was first detailed by Karlsen and Sand (1987) many studies have been reported where a 0.1mM Co2+ 24 hour bath treatment is used to reversibly block the mechanosensory lateral line in different species of teleost fish.
		These studies and others which have shown that apical Ca2+ is critical to the function of both ampullary receptors and the lateral line led us to predict that Co2+ would block both the passive electric sense and the mechanosense of Apteronotus albifrons.
		In addition, because the lateral line receptors are more similar to the auditory system than are ampullary receptors, we expect that ototoxic agents like cisplatin which can block ampullary receptors will also block the mechanosensory lateral line.
	soma.npa.uiuc.edu /labs/nelson/msp_poster_www/treatments.html (457 words)

	Electroreception movies: Apteronotus albifrons discharging (Site not responding. Last check: 2007-10-20)
		Apteronotus albifrons (Linnaeus, 1766), emitting wave-like Electric Organ Discharges with a frequency of about 800 Hz.
		The EODs are recorded with two stainless steel rod electrodes at the left of the tank, and made audible via a loudspeaker.
		As most electroreceptive fish they rely greatly on the electric sense in turbid water they live in.
	www.bio.uu.nl /~rcpeters/Movies/Ster1.htm (74 words)

	APU Evironmental Sciences Research Centre
		The problem of sensory masking: weakly-electric fish as models for the study of the welfare of aquarium fish.
		Several knifefishes (genus Apteronotus, family Apteronotidae, order Gymnotiformes) are popular aquarium fish, especially the two common species Apteronotus albifrons (the Black Ghost Knife Fish) and Apteronotus leptorhynchus (the Brown Ghost Knife Fish).
		Apteronotus have been shown to alter (1) their EOD in relation to environmental stress, especially temperature, pH and pollutants, and (2) their chirp rate in relation to circulating levels of cortisol, the principle stress hormone.
	web.apu.ac.uk /envsci/research/ab_007.htm (329 words)

	Apteronotus albifrons (Black Ghost) (Site not responding. Last check: 2007-10-20)
		Gymnotus albifrons, Sternarchus albifrons, Apteronotus passan, Sternarchus lacepedii, Sternarchus maximilliani
		They will eat floating pellets, sinking pellets, sticks, and tubiflex worms, and live fl worms, mine is around 13 inches and he will eat small live food such rosy reds and small feeders.
		They tend to not bother other fish, as I have small barbs and such with him.
	species.fishindex.com /species_2899apteronotus_albifrons_black_ghost.html (110 words)

	Abstract `Prey capture in the weakly electric fish Apteronotus albifrons ...'
		Prey capture in the weakly electric fish Apteronotus albifrons : Sensory acquisition strategies and electrosensory consequences
		On the basis of infrared video recordings of fl ghost knifefish (Apteronotus albifrons) feeding on small prey (Daphnia magna) in the dark, me reconstruct three- dimensional movement trajectories of the fish and prey.
		In particular, we find that the high-pass filter characteristics of P-type afferent response dynamics can serve as a predictive filter for estimating the future position of the prey as the electrosensory image moves across the receptor array.
	www.neuromech.northwestern.edu /publications/Nels99a/Nels99a_abstract.shtml (176 words)

	Nelson Lab Home (Site not responding. Last check: 2007-10-20)
		We study these processes in the electrosensory system of weakly electric fish, using a combination of behavioral, electrophysiological, and computational neuroscience approaches.
		The animal to the left is a fl ghost knifefish (Apteronotus albifrons).
		These nocturnal fish generate a weak (millivolt-level) electric field, which they use to detect objects in the dark.
	nelson.beckman.uiuc.edu (124 words)

	Immersion Corporation - Digitizer: Case Study Gallery (Site not responding. Last check: 2007-10-20)
		Computer simulation of electrosensory image formation as a fl ghost knife fish (Apteronotus albifrons) hunts for prey using its active electric sense.
		A false color map on the skin indicates the change in afferent firing rate (in spikes/s) due to the electric field perturbation caused by the prey.
		(B) High resolution polygon surface model of Apteronotus albifrons, 1,540 faces total, 70 longitudinal and 22 around.
	www.immersion.com /digitizer/case_study_gallery/scientific_2.php (349 words)

	Caltech CNSE - full report
		Thrust vectors around Apteronotus albifrons for two swimming directions and a roll maneuver.
		The inset plot on the left shows the roll angle history and current value (filled circle).
		Sensory and small-time locomotor volumes around A. albifrons.
	www.erc.caltech.edu /Research/reports/maciver-full.html (793 words)

	ghost knife \| ghost knife Resources
		Ghost Knife Fish, Black Ghost Knife Fish, Speckled Knife Fish[Pictures] Apteronotus albifrons SYN: Sternarchus albifrons; Sternarchusmaximiliani PD: An elongated, laterally compressed species with a...
		This is a Black Ghost Knife, Apteronotus Albifrons, one of my favorite fish.
		Caring for Your New Black Ghost Knife Fish Inside scoop from Aqualand on Apteronotus albifrons Amphibians Axolotls Caecilian Worm Newts General Newts Eastern Newts Mandarin Salamanders Surinam Toad...
	www.bknife.com /a/ghostknife (903 words)

	* Black Ghost - (Aquarium): Definition
		Notice: Micro soft has no responsibility for the content featured in this group.
		chitala Pictus catfish = Pimellodella pictus Columbian catfish = Arius jordani fl ghost knife = Sternarchus albifrons African knives = Xenomystus nigri...
		Bolivian Butterfly (Micro geophagus altispinosa), Silver Hatchetfish (Gasteropelecus sternicla), Black Ghost Knifefish (Apteronotus albifrons), Hoplo (Lepthoplosternum thoracatus),...
	en.mimi.hu /aquarium/black_ghost.html (317 words)

	Abstract `Body modeling and model-based tracking for neuroethology' (Site not responding. Last check: 2007-10-20)
		In this paper we describe methods for precision body modeling and model-based tracking of non-rigid animal movements without the use of external markers.
		We describe the process of obtaining high-fidelity urethane casts of a model organism, the weakly electric knifefish Apteronotus albifrons, and the use of a stylus-type 3-D digitizer to create a polygonal model of the animal from the cast.
		We describe the principles behind markerless model-based tracking software that allows the user to translate, rotate, and deform the polygon model to fit it to digitized video images of the animal.
	www.neuromech.northwestern.edu /publications/MacI00a/MacI00a_abstract.shtml (191 words)

	[No title] (Site not responding. Last check: 2007-10-20)
		Forum: Besatzanfragen Téma: 350l Becken ------------------- coca: Hallo habe ein 350l Becken mit: 3 Malawis Labeotropheus fuelleborni 1 Apteronotus albifrons 2 Ancistrus und 4 kleine Ancistrus in einen aufzuchtbecken, da sie sonnst fischfutter sind.
		Ergänzung: Der Apteronotus albifrons dürfte wohl eine sehr unglückliche Besatzwahl gewesen sein.
		Abgesehen von den WW, kann er bis zu 50cm groß werden, da dürfte dein 350er doch etwas zu klein sein.
	www.biotopforum.at /export.php?mode=txt&t=2343 (350 words)

	[No title]
		MacIver studies Apteronotus albifrons, the fl ghost knife fish.
		Neural engineer Malcolm MacIver grew up in northern Ontario but spends much of his time studying a small fish native to the rivers of the Amazon basin.
		Why Apteronotus albifrons, commonly known as the fl ghost knife fish?
	bydesign.mccormick.northwestern.edu /spring2004/Neural_Engineering.html (1227 words)

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