RV Corella Fisheries Laboratory cooperated with the Admiralty Research Laboratory to identify fish detected by long-range sonar equipment installed at the Admiralty Experimental Station, Perranporth. The RV "Corella" was directed from the shore to an area some 65 km distant, that was returning a strong and extended echo. The "Corella" was able to correlate this target with shoals detected on a conventional echo sounder, and substantial catches of sprats were taken in the area using a midwater trawl. The RV "Corella" was used throughout the 1970s for pioneering studies on fish migration. Individual plaice ("Pleuronectes platessa") fitted with 300 kHz acoustic transponding
Dagetichthys lusitanica Dagetichthys lusitanica Dagetichthys lusitanica, commonly known as the Portuguese sole, is a species of flatfish native to the eastern Atlantic Ocean. Little is known of the abundance or behaviour of this fish, and the International Union for Conservation of Nature has rated its conservation status as being "data deficient". The Portuguese sole grows to a standard length of about . The general shape is oval, tapering somewhat towards the tail. Like other flatfish, the body is flattened laterally and the fish lies on its side, with both eyes on the right side; the upper eye is slightly in front of