NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Development of the Statocyst in the Freshwater Snail Biomphalaria Glabrata (Pulmonata, Basommatophora)The development of the statocyst of the freshwater snail Biomphalaria glabrata has been examined from embryo to adult. Special emphasis was put on the growth of the statoconia in the statocysts. In the statocysts of embryonic snails (90-120 h after oviposition) there is not a single statolith but an average of 40-50 statoconia per statocyst. The number of statoconia increases to 385-400 when the snails reach a shell diameter of 4 mm and remains relatively constant thereafter, irrespective of shell size. Small statoconia are found in supporting cells, which suggests that the statoconia are produced within these cells. The average diameter of statoconia and the total mass of statoconia increase with increasing shell diameter. The average number of large statoconia (diameter greater than 7 micrometers) per statocyst continues to increase from 2 to 10 mm animals while the number of small ones (diameter less than 4 micrometers) initially rises and then decreases after 4 mm. These results demonstrate continuous growth of the statoconia in the cyst lumen of Biomphalaria. The single statoconia vibrate in a regular pattern in vivo, indicating beating of the statocyst cilia. The statoconia sink under the influence of gravity to load and stimulate receptor cells which are at the bottom. The length of cilia and the size of statocyst gradually increase as the animal grows. However, the increase in the volume of the statocyst is relatively small compared with the increase in body weight during normal development.
Document ID
20000012488
Acquisition Source
Ames Research Center
Document Type
Reprint (Version printed in journal)
Authors
Gao, Wenyuan
(Texas Univ. Health Science Center San Antonio, TX United States)
Wiederhold, Michael
(Texas Univ. Health Science Center San Antonio, TX United States)
Hejl, Robert
(Texas Univ. Health Science Center San Antonio, TX United States)
Date Acquired
August 19, 2013
Publication Date
January 1, 1997
Publication Information
Publication: Hearing Research
Publisher: Elsevier Science B.V.
Volume: 109
ISSN: 0378-5955
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: NAG2-952
CONTRACT_GRANT: NSF IBN-95-29136
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available