Biomass, growth and production of the amphipodCorophium insidiosumcrawford, and preliminary notes onCorophium volutator(Pallas)

Publisher Website
Google Scholar
Abstract
Abundance and length distributions of Corophium insidiosum and Corophium volutator were investigated along littoral transects in Holbsek Fjord, Zealand, Denmark. Corophium uolutator predominate in the innermost and Corophium insidiosum in the outermost part of the transects. A maximum abundance of Corophium insidiosum of 140 000/m2 was recorded in early August. A method of measuring the growth of ‘cohorts’ of Corophium insidiosum established in situ in growth cages was developed. Maximum length and maturity are reached within one month and the generation time is about 4-5 weeks in early summer. During the summer maturity is progressively reached at a smaller size and the maximum length is reduced. The production is calculated as the sum of size classes, and the specific growth rates of Corophium insidiosum are derived from the growth of the cohorts in the growth cages. Preliminary growth rates of Corophium uolutator are based on the growth ofnatural populations. The production of Corophium insidiosum from May to September was 0.2-8 g/m2 in dry weight, and the production hiomass ratio (P/B) was between 2-5. The production of Coropbium volutator was 2-4 g/m2 in dry weight and the P/B ratio was 3-4.