Notes on age determination, size and age structure, longevity, and growth of co‐occurring macrourid fishes

Nineteen species of the deepwater fish family Macrouridae inhabit the mid-Atlantic Ridge of the North Atlantic. Size and age structure, longevity, and length-at-age were explored for seven of the more abundant species: Coryphaenoides armatus, C. brevibarbis, C. carapinus, C. guentheri, C. mediterraneus, C. rupestris, and Macrourus berglax. The otoliths from these species had growth increments resembling those accepted as annuli in other deepwater species for which validation experiments have been conducted. Based on the counts of these growth increments, age estimates were derived as basis for studies of age structure, growth and longevity. All the species appeared to have relatively low growth rates, but the interspecific variation in longevity illustrates that there is a considerable variation within the family and amongst species inhabiting the same deep-sea environment. Most of the species likely complete full lifecycles on the mid-Atlantic Ridge, but it is probable that both the youngest and the largest-oldest individuals of some of the species were not sampled adequately