Weight-length relationships for demersal fish species caught off the Madeira archipelago (eastern-central Atlantic)

Length and weight descriptive statistics are reported for 29 demersal fish species caught off the Madeira archipelago during three yearly surveys (1997, 2004 and 2005) using bottom long-lines from depths of 25-1150 m. Weight-length relationships were estimated for 18 of these species. The parameter b ranged between 2.737 in Polyprion americanus and 3.674 in Benthodesmus simonyi. Additionally, in 11 species, parameter a was calculated setting b = 3. To the authors' knowledge all weight-length relationships presented herein are recorded for the first time from the Madeira area, and in the cases of Deania profundorum, Muraena helena and B. simonyi, are the first references worldwide.