Age, growth and reproductive biology of the European conger eel (Conger conger) from the Atlantic Iberian waters

Stock discrimination of European conger eel (Conger conger L.) using otolith stable isotope ratios

“…Since it is accepted that at the onset of the breeding season conger eel probably undergo a migration to deeper waters and stop feeding (Sbaihi et al, 2001;O'Sullivan et al, 2003;Correia et al, 2009), analysis of the otoliths of C. conger adults caught on the spawning ground(s) should allow us to answer the question of their origin and infer about their migration pathway. Juvenile conger eel from these locations can be regarded as discrete populations, although further work is required to determine if they are sourced from separate spawning sources.…”

“…just prior to C. conger's summer breeding season (Wheeler, 1985;Cau and Manconi, 1983). Because sex ratio depends on depth, with males normally absent shallower than 400 m (Sbaihi et al, 2001;O'Sullivan et al, 2003;Vallisheri et al, 2007;Correia et al, 2009) and size at first maturity in females occurring at 200 cm , it was highly likely that all the fish sampled were immature females.…”

“…Sagittal otoliths were removed with plastic forceps, cleaned with Milli-Q water, air-dried in a laminar-flow cabinet, weighed (0.001 g) and stored dry in Eppendorf tubes. Ageing conger eels by standard protocols for otoliths is difficult due to the existence of false rings (Correia et al, 2009). However, based on the average fish length and Von Bertalanffy growth curves for the species (Sbaihi et al, 2001;O'Sullivan et al, 2003;Correia et al, 2009) a mean age of 5 years was estimated for the specimens used in this study.…”

“…The total world catch for 2008 was 16,594 t, with the largest catches being recorded by France (4412 t) and Spain (4029 t) (FAO-FIGIS, 2008). Despite being a geographically widespread and important fisheries resource, knowledge of the population structure and ecology of C. conger is scarce and mainly concerns the early life history (Strehlow et al, 1998;Correia et al, 2002Correia et al, , 2003Correia et al, , 2006a, feeding ecology (Cau and Manconi, 1984), and reproductive biology (Cau and Manconi, 1983;Fannon et al, 1990;Sbaihi et al, 2001;O'Sullivan et al, 2003;Correia et al, 2009).…”

Population structure and connectivity of the European conger eel (Conger conger) across the north-eastern Atlantic and western Mediterranean: integrating molecular and otolith elemental approaches

“…As the spawning season approaches, congers cease to feed (Cau and Manconi 1984), which prevents capture by longlines, and only trawler fishing is effective in capturing conger mature specimens (Fannon et al 1990). As a consequence, most conger eels captured in the coastal inshore waters of the Atlantic are immature (Sbaihi et al 2001;Sullivan et al 2003;Correia et al 2009). An earlier extensive survey in the eastern Mediterranean did capture sexually mature specimens, suggesting the existence of a breeding area for the European conger eel in deep waters southeast of Sardinia (Cau and Manconi 1983).…”