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.

Resource Allocation in the Intertidal Salt-Marsh Mussel Geukensia demissa in Relation to Shore Level

David R. Franz
Estuaries
Vol. 20, No. 1 (Mar., 1997), pp. 134-148
Stable URL: http://www.jstor.org/stable/1352727
Page Count: 15
  • Read Online (Free)
  • 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.
Resource Allocation in the Intertidal Salt-Marsh Mussel Geukensia demissa in Relation to Shore Level
Preview not available

Abstract

Ribbed mussel populations at two levels of the intertidal shore were studied for 3 yr at a salt marsh site in Jamaica Bay (New York). Length-specific dry body weight was determined monthly and shell growth was monitored between April and November of each year. Production ( P t) was measured as monthly changes in body dry weight. Annual reproductive output ( P R) was estimated indirectly for mussels between 10 mm and 80 mm by determining the gain in body weight prior to spawning (Weight Gained Method). Using a second method (Basal Weight Method), monthly rates of somatic production ( P g) were determined by assuming that, as mussels grow in length, a fraction of monthly P t is allocated to increasing body weight. The monthly production allocated to growth ( P g) was estimated based on the length-specific body weight (basal weight) in March, when body weights in these populations begin to increase due to gametogenesis. Monthly rates of reproductive output ( P r) were then estimated be substraction as the difference between monthly P t and P g. Total P R determined by both methods were very similar. Shell and body growth were concurrent in sexually immature mussels, but body weight preceeded shell growth in older, larger animals. Annual shell increments were correlated with annual P G. In sexually mature mussels, P r preceeds P g in larger mussels, that is, allocations of net production to reproduction and somatic growth diverge in time with increasing shell length. Between April and November, shell growth rates were correlated with water temperature. At the higher shore level, mussels allocated a much smaller proportion of total production to growth, exceeding the reproductive effort of the lower-shore population. Variation in mussel production between years probably is related to variability in nannoplankton biomass. Although mussels higher on the shore can reduce somatic growth in order to increase fecundity and reproductive effort, total reproductive output is much reduced as compared to the marsh edge.

Page Thumbnails

  • Thumbnail: Page 
134
    134
  • Thumbnail: Page 
135
    135
  • Thumbnail: Page 
136
    136
  • Thumbnail: Page 
137
    137
  • Thumbnail: Page 
138
    138
  • Thumbnail: Page 
139
    139
  • Thumbnail: Page 
140
    140
  • Thumbnail: Page 
141
    141
  • Thumbnail: Page 
142
    142
  • Thumbnail: Page 
143
    143
  • Thumbnail: Page 
144
    144
  • Thumbnail: Page 
145
    145
  • Thumbnail: Page 
146
    146
  • Thumbnail: Page 
147
    147
  • Thumbnail: Page 
148
    148