The silver-cheeked toadfish (Lagocephalus sceleratus)
is an invasive species of highest concern. Its population must be
controlled to mitigate its negative impacts on marine ecosystems,
fishers, fisheries and human health. This study thoroughly investigates
the biology, diet and catchability of the L. sceleratus stock
from Finike, Turkey from March 2017 to February 2018 in order to better
manage its invasion. A total of 751 specimens were sampled for this
study with a M/F ratio of 1.25/1. The species becomes sexually mature at
three and a half years of age, and Lm50 was 41.39 cm for
males and 42.08 cm for females. Its spawning season in this region was
from June to August, peaking in July. Its diet was mostly crustaceans in
spring, fish in summer and both fish and crustaceans in winter. This
species consumed a large amount of other pufferfish species, resulting
in over a quarter of its fish diet. The trophic level of L. sceleratus was 4.41, demonstrating that it is indeed a top predator carnivore in
the eastern Mediterranean Sea. Ingested fishing gear parts such as net
pieces and hooks were found in about 10% of the fish. A slight
modification of longlines using steel branch lines and a swivel hook
resulted in double the catch per unit effort than standard longlines, so
this technique can be used to target and control more of this invasive
species, which is a national priority. |