Annual Life Cycle and Production of the Chaetognath Sagitta elegans in Bedford Basin, Nova Scotia

Abstract

In Bedford Basin, Nova Scotia, Sagitta elegans has two main generations per year, one in the spring and one in the fall. The biomass of S. elegans per 100 m³ of water was an order of magnitude greater in the Basin than that reported previously for St. Margaret’s Bay, N.S. The growth rate and the number of degree days needed to mature were similar to those found for S. elegans in St. Margaret’s Bay. Annual turnover rate for S. elegans in the Basin was 5.6 and yearly production was estimated at 27.0 kcal per year or 9.0% of the yearly copepod production. It was calculated that the species used 90.4 kcal per m² per year in respiration. The percentage of the total yearly production of copepods consumed by S. elegans was estimated at 36%.