Did you know that anglerfish can be predators of loggerhead sea turtles in the Med?
Thanks to ARCHELON’s nationwide sea turtle Stranding Network*, anglerfish were recorded as opportunistic predators of sea turtles in the Med for the first time. A juvenile loggerhead turtle was found in the stomach of an anglerfish! Here is the story:
On 13 March 2010, the Coast Guard officers on duty at the fish market of Nea Mihaniona in northern Greece, conveyed to ARCHELON a Stranding Sheet reporting a juvenile Caretta caretta that was taken out of the stomach of a 65 cm long (total length) anglerfish (Lophius sp). The turtle, fresh and totally intact, was photographed and measured (30 cm straight carapace length, 25 cm straight carapace width) by the Coast Guard officers. The turtle’s total length was estimated at 40–45 cm.
Loggerheads are predated at various stages of their life cycle by several species of marine and terrestrial animals. In the marine environment, it is assumed that predation rates are greater at early life stages and decline as turtles gain larger sizes. Marine predators for larger size loggerheads are mainly sharks as well as Mediterranean Monk Seals and large fish.
As far as can be ascertained no previous record of loggerhead predation by anglerfish has been reported in the Mediterranean Sea. Anglerfish are distributed widely in the Mediterranean as well as in the eastern Atlantic and are a target species of bottom-trawl fisheries. They are known as opportunistic predators feeding mainly on fish, crustaceans, and to a lesser extent on cephalopods, gastropods, bivalves, and echinoderms. Among 61 fish species examined in the northern Aegean Sea, anglerfish had the largest mouth openings. Anglerfish rest on the seafloor and take passing prey by surprise or by luring prey with their angling spine (illicium) close to their wide mouths. Τherefore, anglerfish are not selective with their prey.
As Androniki Pardalou, oceanographer, informed us, it has been observed that anglerfish, when caught in a fishing trawl net, often swallow up anything that may lay beside them. So the turtle in this particular case may have been trapped in a trawl net with the anglerfish, and subsequently ended up in its’ stomach.
A full note on this was published in the Natural History Notes of the Herpetological Review 50(4), 2019, Dimitris Margaritoulis and Pavlos Tsaros/ ARCHELON.
(*) The Stranding/Rescue Network for sea turtles is operated by ARCHELON since 1992 and its members are Coast Guard officers, local Societies and concerned citizens, who collect data from dead turtles and help transfer injured turtles to the Rescue Centre, near Athens.