Production of Oikopleura longicauda (Tunicata: Appendicularia) in Toyama Bay, southern Japan Sea

Abstract

Oikopleura longicauda occurred throughout the year in Toyama Bay, southern Japan Sea, and analysis of its size composition and maturity revealed that reproduction was continuous over the year. Somatic growth production (P(g)) varied with season from 0.03 to 103 mg carbon (C) m-2 day-1 (annual P(g) 4.5 g C m-2), and house production (P(c)) from 0.11 to 266 mg C m-2 day-1 (annual P(c) 11.3 g C m-2). The annual P(g)/B ratio was 176. Compared with production data of some predominant zooplankton species in Toyama Bay, it is suggested that despite their smaller biomass, appendicularians are an important secondary producer.