Published online by Cambridge University Press: 23 December 2010
The sandpaper skate, Bathyraja kincaidii, is one of four skate species commonly taken in trawl fisheries off central California although very little is known about its life history. In this study, age and growth were evaluated from 187 vertebrae using a common growth band counting method. An attempt to use marginal increment analysis and centrum edge analysis failed to validate the annual periodicity of growth band formation; however, it is a valid assumption based on structural similarity from other studies. Assuming annual band formation, von Bertalanffy growth parameters were determined for females (L∞ = 537.3 mm; k = 0.237; to = –1.629; N = 99) and males (L∞ = 580.2 mm; k = 0.185; to = –2.530; N = 88). Maximum likelihood ratios indicated no significant difference (P > 0.05) between male and female von Bertalanffy growth parameters, thus data were combined (L∞ = 557.8 mm; k = 0.207; to = –2.147; N = 187). Age estimates from band counts in vertebral centra indicated a minimum longevity of 17 and 18 years for female and male B. kincaidii, respectively. Caudal thorns were also assessed for age analyses, but were deemed unreliable and could not be used to verify age estimates from vertebral centra.