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Rough-toothed dolphin's abundance and distribution is largely unknown worldwide and evaluation of its conservation status in the Mediterranean Sea is necessary. A rough-toothed dolphin was sighted offshore Eastern Sicily (Mediterranean Sea) in July 2017 and acoustic data were acquired in the same area of Watkins, Tyack, Moore, and Notarbartolo di Sciara [(1987). Mar. Mamm. Sci. 3, 78–82]. An automatic detection algorithm was developed to identify the echolocation clicks recorded within both datasets and a recurrent inter-click interval value was identified during the new encounter. Distinctive whistle classes were also identified with similar contour shapes within both datasets. [ABSTRACT FROM AUTHOR]

This study describes the underwater acoustic behavior of the red swamp crayfish Procambarus clarkii. The study was conducted both in a tank and in the natural environment. The tank was equipped with video and acoustic recording systems. Observations were conducted to identify the underwater acoustic signals produced and their association with behavioral events and the movement status of the animals. In a lake in a natural reserve, a remote acoustic recording station was used to study the circadian underwater acoustic activity of the crayfish and to assess the acoustic features of the signals. The red swamp crayfish produces irregular trains of wide-band pulses (duration 0.4 ms, SPLPK 128 dB re 1 μPa, peak frequency 28 kHz, bandwidthRMS 20 kHz). The production of signals is positively related to intraspecific interactions (encounter/approach, fighting and successive Tail Flips). In the natural environment, acoustic activity is almost absent during the day, increases abruptly at sunset and continues until dawn. This study reveals the previously unknown underwater acoustic signals of Procambarus clarkii and the potential of passive acoustic methods to monitor the presence, the abundance and the behavioral activities of this invasive species. [ABSTRACT FROM AUTHOR]