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Table 1 Secondary production of the cohorts of the population

From: Reproduction, population dynamics and production of Nereis falsa (Nereididae: Polychaeta) on the rocky coast of El Kala National Park, Algeria

Cohort Wt Wt2 − Wt1 Nt Nt1 + Nt2/2 Production (g for 6 m2)
January 0.095 – 63 – –
February 0.108 0.013 87 75 0.975
March 0.135 0.027 58 72.5 1.957
April 0.130 −0.005 47 52.5 −0.262
May 0.132 0.002 61 54 0.108
June 0.147 0.015 82 71.5 1.072
July 0.165 0.018 70 76 1.368
August 0.149 −0.016 72 71 −1.152
Total C1      4.066
September 0.083 0.083 82 41 3.403
October 0.100 0.017 62 72 1.224
November 0.105 0.005 74 68 0.340
December 0.100 −0.005 52 63 −0.315
Total C2      4.652
Total      8.718
  1. Wt mean weight variation of a cohort between t1 and t2, Wt 1 and Wt 2 mean fresh weights of a cohort at times t1 and t2, Nt number of individuals in a cohort at times t, Nt 1 and Nt 2 numbers of individuals in a cohort at times t1 and t2
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Helgoland Marine Research

ISSN: 1438-3888

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