Acoustic Signatures of Three Marine Arthropods, Squilla mantis (Linnaeus, 1758), Homarus americanus (H. Milne Edwards, 1837), and Nephrops norvegicus (Linnaeus, 1758) (Arthropoda, Malacostraca)

The acoustic signatures of three marine crustaceans, Squilla mantis (Linnaeus, 1758), Homarus americanus (H. Milne Edwards, 1837), and Nephrops norvegicus (Linnaeus 1758) (Arthropoda, Malacostraca), were experimetally determined in measurements using the calibration tank at the NATO Undersea Research Center, Le Spezia, Italy. The specimens were insonified at 45 rotational intervals with a sound source emitting pings from 30 to 120 kHz. For all three species, the value of the nondimensional parameter ka (where k is the acoustic wave number and a is the characteristic dimension of the object) was 5. The absorption specta, defined as the frequencies at which the intensity of the reflected sound was less than 5% of the incident intensity, were determined. These sepctra changed with the changing aspects and were unique for each animal in this study. Two of the species were in the same infraorder. Astacidea, Our reults contribute to the development of an acoustic identification system for surveys of marine animals.