Distribution of Triaenophorus crassus Parasites in Whitefish Flesh and its Significance to Automatic Detection of the Parasites with Ultrasound

Abstract

The three-dimensional distribution of Triaenophorus infection in the whitefish (Coregonus clupeaformis) body and the ultrasonic echos received from the parasite cysts are studied in relation to the problem of detecting the parasites with ultrasound. It is shown that ultrasonic scanning of only 15% of the total surface area of a whitefish is required to illuminate (on the average) 70% of the total number of cysts in the body. As a result the search effort required for effective ultrasonic parasite detection can be greatly reduced. A considerably larger ratio of infection (3:2) for the right and left sides of the body is observed than has been previously reported. It is also shown that in the epaxial muscles a parasite is much more likely to be encysted near the surface than deep inside the flesh. Measurements of the ultrasonic cyst-echo durations yielded a distribution with two peaks of different amplitudes indicating a preponderance of spindle-shaped cysts as is actually observed. A negligible percentage of the echos in the distribution are less than 2 μsec in duration; the median width is 6.4 μsec. An outline is given of how these findings can be used to reduce the error rate in an automatic detection system. The paper concludes with a brief discussion of the effects of the transducer aperture on the latter distribution.

Advanced Techniques for the Intelligent Diagnosis of Fish Diseases: A Review

“…The use of ultrasound for the detection of parasites in fish has been studied for decades. Freese proposed the early use of ultrasound for the detection of trichinella in whitefish [ 129 ]. This study used ultrasound echoes of the parasite to localize and study the three-dimensional distribution of the parasite in the fish.…”

Effects of Parasite Attributes and Injected Current Parameters on Electromagnetic Detection of Parasites in Fish Muscle

“…Alternatives for detecting parasites in fillets have been investigated. Laser candling (Hawley 1988), ultraviolet candling (Pippy 1970), conventional X-ray techniques (Hawley 1988), and ultrasonic techniques such as the scanning laser acoustic microscope (SLAM) and the pulse-echo technique have been investigated (Hafsteinsson and others 1989;Hawley 1988;Hafsteinsson and Rizvi 1987;Freese 1969Freese , 1970. None of these methods proved commercially viable due to low sensitivity, poor resolution, and slow throughput.…”

Detection of Parasites in Fish by Superconducting Quantum Interference Device Magnetometry

“…Conventional X-ray has not been effective (Hawley, 1988) because of an insufficient difference in density between nematodes and surrounding muscle. Ultrasonic techniques such as the scanning laser acoustic microscope (SLAM) and the pulse-echo technique have been investigated (Hafsteinsson et al, 1989;Hawley, 1988;Hafsteinsson and Rizvi, 1987;Freese, 1969Freese, , 1970 but were unsuccessful in distinguishing parasites from surrounding flesh. The differences in physical properties of nematodes and surrounding fish tissue have been too slight (Hawley, 1988).…”