To induce sexual maturation in captivity, eels rely on hormonal treatments, but this process is costly and time-consuming. As an alternative, different types of conditioning, also referred as pre-treatment, have been assessed to ease hormonal treatment response. Recent studies have shown that migrating eels experience a wide range of temperatures, varying from 12 °C at night to as low as to 8 °C during the day. Therefore, this...

Winter conditions are rapidly changing in temperate ecosystems, particularly for those that experience periods of snow and ice cover. Relatively little is known of winter ecology in these systems, due to a historical research focus on summer ‘growing seasons’. We executed the first global quantitative synthesis on under‐ice lake ecology, including 36 abiotic and biotic variables from 42 research groups and 101 lakes, examining...

This paper reports on an evaluation of growth, gonadal development and reproductive endocrinology of older triploid (3 n ) European sea bass Dicentrarchus labrax in comparison with their diploid (2 n ) counterparts throughout their fifth and seventh annual cycle of life. While older triploids retained impaired reproductive endocrinology, a sexually related dimorphic growth was observed with 3 n females attaining the largest si...

Gynogenesis showed little effect on general physiology and gonadal development in sea bass Dicentrarchus labrax . Meiogynogenetic fish showed well‐developed gonads indicating low occurrence of developmental imbalances even after gynogenesis induction in this species. In addition, the proportion of sexes of meiogynogenetic sea bass was similar to the diploid controls in two independent trials, which did not deviate significantl...

Twenty‐day exposures to 17α‐methyltestosterone (MT) (10 mg kg‐© 1 food) starting at 86 or 106 days post fertilization (DPF) resulted in a complete masculinization of sea bass Dicentrarchus labrax , as opposed to 46% females present in the controls. Earlier exposures failed to suppress ovarian development, resulting in a variable number of females (range 10·5–49·5%). All treatments assayed between 110 and 210 DPF induced a comp...

During their 3–4 first years of life, triploid sea bass Dicentrarchus labrax grew in a similar fashion to diploids in fork length but more slowly than diploids ( P 1 kg) sea bass. The condition factor was reduced in both ploidies during the spawning season which took place in winter when the temperature was low. These observations suggest that any growth advantage in triploids, which were functionally sterile, may be offset by...