Accession Number:

AD0763176

Title:

The Brackish Water Clam Rangia cuneata as Indicator of Ecological Effects of Salinity Changes in Coastal Waters.

Descriptive Note:

Final rept.,

Corporate Author:

TEXAS A AND M UNIV COLLEGE STATION DEPT OF BIOLOGY

Report Date:

1973-06-01

Pagination or Media Count:

262.0

Abstract:

In the search for a laboratory test that could be used to determine when estuarine salinity changes were favorable or unfavorable, salinities in the range from 0 to 38 were tested on adult Rangia clams for effects on survival regulation of internal salinity intake, use and release of amino acids respiration glycogen use under aerobic and anaerobic conditions feeding rate ciliary activity uptake of glucose glycogen storage and index of condition in natural environments through a seasonal cycle carbohydrate-digesting enzymes and reproduction. It was determined that Rangia cuneata has a system of compensating reactions that allows it to adjust to changes in salinity over the range from 0 to 38 ppt and over the temperature range from 10 to 35C without harm. It was concluded from these and further studies that the key to the welfare of a Rangia population is not the physiology of the adult individuals, but reproduction and recruitment. The keys to the use of Rangia cuneata as an indicator were found to be two facts 1 a change in salinity, either up from near 0 or down from 15 ppt and above, is necessary to induce spawning 2 the embryos and early larvae can survive only in salinities between 2 and 10 or 15 ppt. Modified author abstract

Subject Categories:

  • Biological Oceanography
  • Water Pollution and Control

Distribution Statement:

APPROVED FOR PUBLIC RELEASE