Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Energy Partitioning in Semelparous and Iteroparous Triclads

A. S. Woollhead
Journal of Animal Ecology
Vol. 52, No. 2 (Jun., 1983), pp. 603-620
DOI: 10.2307/4575
Stable URL: http://www.jstor.org/stable/4575
Page Count: 18
  • Read Online (Free)
  • Download ($18.00)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Energy Partitioning in Semelparous and Iteroparous Triclads
Preview not available

Abstract

(1) Under conditions of total starvation, B. punctata maintained capsule production and suffered greater rates of degrowth than controls; P. torva also maintained capsule production and suffered rates of degrowth that were not significantly different to controls; P. nigra ceased capsule output upon starvation. (2) The effect of partial starvation was a reduction in capsule output for all species. B. punctata preserved capsule output to a greater extent than P. torva or D. lugubris. Degrowth rates were greater for P. torva and B. punctata than for D. lugubris at normal feeding levels. As F.S.I. reduced, similar rates of degrowth were suffered by all species. (3) Mortality levels during reproduction and starvation were high for B. punctata and P. torva but low for D. lugubris. (4) Reproductive energy loss, in absolute terms, was greater for B. punctata than for P. torva or D. lugubris. Reproductive efficiency increased as F.S.I. reduced for B. punctata and D. lacteum but either remained constant or reduced for P. torva, P. tenuis and D. lugubris. (5) The hatchlings of the annual species, B. punctata and P. torva, were better able to cope with nutritive stress than the hatchlings of the perennial species, D. lugubris.

Page Thumbnails

  • Thumbnail: Page 
603
    603
  • Thumbnail: Page 
604
    604
  • Thumbnail: Page 
605
    605
  • Thumbnail: Page 
606
    606
  • Thumbnail: Page 
607
    607
  • Thumbnail: Page 
608
    608
  • Thumbnail: Page 
609
    609
  • Thumbnail: Page 
610
    610
  • Thumbnail: Page 
611
    611
  • Thumbnail: Page 
612
    612
  • Thumbnail: Page 
613
    613
  • Thumbnail: Page 
614
    614
  • Thumbnail: Page 
615
    615
  • Thumbnail: Page 
616
    616
  • Thumbnail: Page 
617
    617
  • Thumbnail: Page 
618
    618
  • Thumbnail: Page 
619
    619
  • Thumbnail: Page 
620
    620