Frequently Asked Questions
What is the purpose of this site?
This archive was established by the Troy Smith Laboratory at Indiana University. The purpose of the archive is to make recordings of electrocommunication signals of weakly electric fish available for research and teaching. The recordings currently on the site were made from several species of South American ghost knifefishes (Gymnotoformes: Apteronotidae) as part of a project to characterize species diversity and sexual dimorphism in electric communication signals (electric organ discharges (EODs) and chirps) in this group. This archive was established and is maintained with supported by a grant from the National Science Foundation (IOS 0950721).
How were the recordings made?
Most of the recordings on this site were made in chirp chambers. Fish were placed in PVC shelter tubes within a tank with carbon electrodes at the ends of the tube to record their EODs. Simulated EODs (sinusoidal voltage signals) at a range of frequencies were presented through carbon playback electrodes placed orthogonally to the recording electrodes. Typical playback frequencies were -150 Hz, -20 Hz, -5 Hz, +20 Hz, and +150 Hz relative to the fishes' own EOD frequencies. The playbacks had field strengths of 0.6-1.5 mV/cm recorded midway between the playback electrodes. Recordings came either from fish within a few days of collection from the field or from wild-caught fish housed and recorded in the laboratory. Baseline recordings are typically 4 minutes long without playback. Playback recordings consist of a 1-minute baseline period, 2 minutes of playback, and a 1-minute post-playback period without playback. Most fish respond to the playbacks by producing chirps (transient increases in EOD frequency sometimes accompanied by decreases in EOD amplitude). The recordings were digitized with a sound card at 44.1 kHz and stored as .wav files.
How do I use this site?
This site provides a catalog of information about our fish and links to our recordings, which are stored on the Indiana University Scholarly Data Archive (SDA) servers. The recordings are organized by individual fish, and the fish are organized by genus and species.
To browse the records by genus, follow the links on the catalog home page or in the left-hand menu.
To search the records by genus, species, origin, and/or sex, use the Advanced Search feature.
In each record, you will find the fish's unique ID; its sex, mass, length, and origin (if available); and an expandable table of available recordings with links to the files. The "Date" column contains the date the recording was made, the "Stimulus" column the playback signal, "Duration" the length of the WAV file, "Recorded By" the names of the lab members who produced the recording, and "Download" the links to and sizes of each file. The difference between Original and PBR files is explained below. Some records also contain photographs of the fish. Funding sources are acknowledged at the bottom.
What is the difference between the "Original" and "PBR" files?
Original files are stereo files that include the recording from the recording electrodes on the left channel, and a copy of the signal sent to the playback electrodes on the right channel. The recording electrodes often pick up some of the playback signals as well as the signals of the fish we are recording. PBR files are mono files in which the contamination of the playback signal picked up by the recording electrodes has been digitally removed using a custom-written procedure in Igor Pro (efish by Brian Nelson). In most cases, we recommend that visitors download the PBR files.
Are there any conditions for using recordings from this site?
Recordings from this site are free for use for non-profit purposes, with three conditions.
- If you use the recordings on this site, please let us know who you are and how you plan to use the recordings. (You will be prompted for this information automatically the first time you click to download a recording. If you have cookies disabled on your browser, please allow an exception for "www.indiana.edu/~efishlab/catalog" to prevent the form from popping up every time you download a recording.)
- Please acknowledge this site and the funding source in any publications or products that result. Suggested acknowledgment format: "The [electric fish recording(s)] were made by [individual who made the recording] and were downloaded from the Smith Laboratory Electric Fish Signal Archive maintained at Indiana University with support from the NSF (IOS 0950721) [and any additional funding sources noted in the recording]".
- Please send copies of any publications or other products to us so that we can document the usage of the archive.
Can I donate my own recordings to the archive?
If you have recordings of electric fish communication signals that you would like to share on this site, please contact Troy Smith to get more information about how to donate recordings to make them available to other researchers and teachers.
How do I download the recordings?
Right-click the file you want to download and select "Save Link As" (or "Save Target As," "Save Linked Content As," or similar, depending on your browser). Select your preferred destination and click "Save" to download the file.
The files can be listened to as a sound in any program that plays .wav files (e.g., Windows Media Player, Adobe Audition). They can also be analyzed by importing the .wav file into a signal analysis program (e.g., Igor).
Can I download all of the recordings at once?
Because the recording files are large and are stored individually on the SDA servers, there is no efficient way to download them in batches or all at once directly from this site.