October 16th, 2010 by Richard Lord
Gary Crane received a shock when he landed a 10 lb. 14 oz 11 dram (4.95 kgs) female marbled electric ray, Torpedo marmorata, on Richard Seager’s ‘Out of Blue‘, while fishing about three miles to the east of Sark on 15 October 2010. The electric ray had a total length of 58.6 cm and a disc width of 41.5 cm. The electric ray took a whole black bream, Spondyliosoma cantharus, presented as bait. This specimen represents the largest marbled electric ray caught by an angler in British waters.
Marbled electric rays frequent the south coast of Guernsey and Sark waters during the autumn months. Marbled electric ray are a southern species more commonly found in the Mediterranean.
They grow to a much smaller maximum size than the electric ray, Torpedo nobiliana, which has been recorded to a size of 180 cm total length and a maximum weight of 90 kgs. Fish identification books report that the larger common electric ray, Torpedo nobiliana, is found in the English Channel, but they have not been recorded from Guernsey waters.
The marbled electric ray, Torpedo marmorata, lies buried in the substrate with only its eyes and spiracles protruding above the sea floor. This fish has a small mouth. The mouth width of this individual was 41 mm.
The fish stuns prey with electricity generated by modified muscle cells located in the anterior and proximal portion of the pectoral fins. These battery-like muscle cells can generate 200 volts. They are translucent and form a kidney-shaped swelling on either side of the head.
Because these muscles are not involved in locomotion, the electric rays have a much larger caudal fin for propulsion than rays in the family rajidae. As a large portion of the pectoral fins are composed of muscles to generate electricity, there is very little edible muscle on the fish and consequently it is of no commercial seafood value.
The inshore waters around Sark may be a breeding area for the marbled electric ray, Torpedo marmorata, as divers have reported congregations of them on the sea floor at certain times of year. Females give live birth. Newborns emerge at a length of 10 to 14 cm. Their electric organs are functional before being born.