Feeding ecology of the crab Cancer polyodon in La Herradura Bay, northern Chile. I. Feeding chronology, food intake, and gross growth and ecological efficiency

Abstract

Gross growth efficiency (K1) and the ecological (=population production) efficienty (EE) were calculated in conjunction with growth and production data from a previous study. C. polyodon feeds at night and to a lesser extent during the day. In winter, night feeding lasted about twice as long (13-15 h) as in spring, but maximum stomach fullness reached only 0.35% BW (body weight) compared to 0.62% BW in spring. Summer feeding resembled the spring pattern and autumn feeding the winter pattern. Daily rations increased from 2.8 (±0.71)% BW in summer and decreased to 2.7 (±0.37)% BW in autumn (annual average: 3.19% BW). K1 (weight gain as % of total food ingested) was lower for females (5.3) than for males (10.3), as females convert a high fraction of ingested food into egg production instead of growth. EE [(population biomass production)/(food ingested)] was estimated at 17.8%. -from Authors