Age and growth of anglerfish (Lophius piscatorius) on the Porcupine Bank (west of Ireland) based on illicia age estimation.

Abstract The age of white anglerfish ( Lophius piscatorius ) on the Porcupine Bank was estimated based on the age estimation of 979 illicia (first dorsal fin ray) obtained from a series of 9 annual groundfish surveys (2001–2009). Modifications in the methodology of illicia preparation and in the traditional biased age estimation criterion are presented. This is the first time that a growth pattern of white anglerfish based on illicia age estimations can be indirectly validated by tracking cohorts using the abundance indices per age class from surveys and length-frequency analyses. Previous studies of cohort tracking using the traditional illicia age estimation criterion showed a mismatch, suggesting a faster growth. With the new proposed criteria, abundant cohorts from 2001 to 2004, and scarce ones, from 2005 to 2007, can be tracked over the time throughout several age groups. A new growth pattern and von Bertalanffy growth parameters are presented ( L ∞ : 162.31; k : 0.088; t 0 : −0.894). The results are compared with previous studies in other areas.