Closing the cycle of the European eel Anguilla anguilla

Closing the European eel life cycle in captivity for a self-sustained and sustainable eel aquaculture requires efficient hatchery technology and techniques. With this goal in mind, EU-supported research initiatives set out in the beginning of this century to develop procedures for captive reproduction and larval culture aiming at glass eel production. These efforts have led to two decades of successful achievements through dedicated international and national efforts. This targeted research ranges from development of broodstock feeds and assisted reproduction protocols applying hormone therapy, thereby enabling production of high-quality gametes and viable offspring (Tomkiewicz et al., 2019, Jéhannet et al., 2024) to the establishment of culture technology and techniques as well as formulation of feeds for ongrowing larvae sustaining their development into the leptocephalus stage (Politis et al., 2021; Benini et al., 2023; Bandara et al., 2024).

While new knowledge, products and methods have incrementally extended longevity, variable reproduction success, offspring quality and high mortality in the early larval stages challenge upscaling of larval culture and the completion of the larval phase. These challenges have urged researchers to revisit procedures with the aim to enhance quality and survival through different stages. This presentation will overview progress in European eel offspring production and larval culture and discuss bottlenecks and impediments that need attention spanning from reproduction through the larval culture to reach metamorphosis and the glass eel stage in sufficient numbers. Among other, we look at the still limited insights in larval demands to ambient culture conditions and stage specific nutritional requirements and preferences, but also the efficiency required for an efficient hatchery production and commercial closed-cycle production of European eel.