Age and Growth of the Cunner, Tautogolabrus adspersus (Walbaum) (Pisces: Labridae) in the Weweantic River Estuary, Massachusetts

Abstract

The scale method is a valid means for age assessment and back-calculating previous growth for the cunner,Tautogolabrus adspersus (Walbaum) in the Weweantic River estuary, Massachusetts. Examination of cunner scale growth from July through October indicates that only one annulus is formed per year, probably during late May or June. A linear body length-scale length relationship used for back-calculation of total length is: (TL=20.35 mm+0.7555 SR). The origin of scale development in the cunner is shown to be on the caudal peduncle at 14 mm TL. Lee’s phenomenon, whereby length at age is increasingly underestimated from scales of progressively older fishes, is not evident in back-calculated growth data. The validity of using average calculated length-at-age data to describe cunner growth is demonstrated. Growth in length of Weweantic cunners is relatively slow; average backcalculated lengths for the first five years of life were 46.5, 88.3, 124.8, 153.1, and 176.5 mm TL. The von Bertalanffy equation, 1t=284.77 (1−e−0.1979 (t−0.1044)), adequately describes growth in length for age groups I to V. Various length-weight relationships are derived which satisfactorily characterize growth in weight of Weweantic fish. The youngest age groups of cunner exhibit the greatest relative increase in body weight and relative weight growth during the second growing season is 11 times as great as as that observed during the fifth growing season.