• Freshwater
  • Marine

CEMG2 Series

  • Product Type Icon Tag

Coded sensor transmitters

Based upon its predecessor (the EMG electromyogram transmitter), the coded electromyogram (CEMG2) transmitter represents one of the components of a field-proven system which enables researchers to record physiological data from free-swimming fish.

Designed to be mounted either externally or internally, CEMG2 transmitters measure muscle activity using probes inserted into the musculature of the fish. The CEMG2 Series provides you with a powerful quantitative estimate of the energetic costs associated with physical activity.


  • Burst interval (BI) available from 2 to 60 seconds in 1 second increments
  • Product Features

    EMG tags allow researchers to:

    • Investigate the metabolic costs associated with such activities as tail-beat frequency
    • Calibrate to oxygen consumption through a series of measurements taken during periods of controlled activity
    • Calculate and compare the energetic costs of various activities

    Compatible with Lotek VHF radio receivers: SRX-DL3, SRX 400A W32 or W5XS, SRX 600 or SRX 800

  • Product Applications

    Radio telemetry has been used to obtain relative or qualitative estimates of fish activity, for the most part, through the use of mercury switches. The CEMG2 transmitter, in conjunction with the SRX receiver/dataloggers and peripherals, offers an incomparable means of quantitatively addressing activity and energy budget issues both in the lab and in the field, without the need for mercury switches.

    Applications include:

    • assessing velocity barriers such as those presented in natural points of difficult passage, or man made barriers including culverts, bridges, dams, etc.
    • assessing the effect of temperature or chemical plumes
    • designing bypass structures by examining in-situ energy expenditures of fish in response to flow rate changes and structural design changes in ladders, weirs, etc.; and
    • effectively monitoring and assessing entrainment in-situ through use of the CEMG2/SRX system on a continuous basis.

    EMG References

    Further information regarding surgical procedures, placement of transmitter, operations in the laboratory and the field can be found in:

    Weatherley, A.H., Rogers, S.C., Pincock, D.G. & Patch, D.G. (1982). Oxygen consumption of active rainbow trout, Salmo gairdneri Richardson, derived from electromyograms obtained by radiotelemetry. J. Fish Biol. 20, 479-489.

    Kaseloo, P.A., Weatherley, A.H., Lotimer, J.S. & Farina, M.D. (1991). A biotelemetry system for transmission of electromyograms in fish as indicators of physical activity. J. Fish Biol.

    McKinley, R.S. (1991). Measurements of activity and oxygen consumption for adult lake sturgeon in the wild with radio transmitted EMG signals. Ontario Hydro Research Division. Report CB91-1-K

    Thorstad, E.B., Okland, F., FInstad B. & McKinley, R.S. (1998). Development and use of EMG telemetry transmitters recording fish muscle activity. Proceedings of the Nordic Conference on Fish Passage.

    Okland, F., Thorstad, E.B., Finstad, B. & McKinley, R.S. (1998). EMG radio transmitters – a new method to record activity, swimming speed and migratory costs in upstream migrating salmonids in situ. Proceedings of the Nordic Conference on Fish Passage.

  • Product Specifications

    Model Physical specifications Life (days)
      Weight in air (g) Weight in water (g) Size (ØxL) (mm) 2s interval 5s interval
    CEMG2-R11-18 10 4.9 11 x 54 51 63
    CEMG2-R11-25 12 5.7 11 x 62 74 89
    GEMG2-R11-35 15 6.7 11 x 72 104 125
    CEMG2-R16-25 25 13 16 x 62 178 215
    CEMG2-R16-33 29 15 16 x 70 245 296
    CEMG2-R16-50 33 16 16 x 87 356 430
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