1994 Fiscal Year Final Research Report Summary
Mechanisms for substrate preference by corals
| Project/Area Number |
04454010
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
生態学
|
|---|
| Research Institution | University of the Ryukyus |
|---|
Principal Investigator |
YAMAZATO Kiyoshi University of the Ryukyus, College of Science, Professor, 理学部, 教授 (80044973)
|
|---|
| Project Period (FY) |
1992 – 1994
|
| Keywords | Pocillopora / Planula larvae / Substrate preference / Sediment rejection / Beach sand / Red soil / Calcareous plate / Biofilm |
|---|
| Research Abstract |
Many researches were done on subustrate preference by corals, but almost none of them included particulate deposits. On the other hand, corals are capable of removing the particles falling on them by cilia and mucus. This is a study on the mechanisms of selecting the grain types and sizes.
Pocillopora damicornis and Stylophora pistillata are main animals used. Beach sand and red terrestrial soil are the main types of substrates. They were sieved into different grain sizes before use.
The reproduction of P.damicornis were ascertained first to take place in May-December, once a month during first quarterfull moon periods. The settling rate of P.damicornis was found to be 7.1%, whereas, that of S.pistillata 51.7%. On the contrary to general trends that coral planulae prefer biologically treated substrate, the planulae of P.damicornis orefered nontreated over treated substrate. Preference of these planulae for beach sand was in the following order : 0.5mm>1mm>5mm>2mm>calcareous plate. The beach sand and red soil of less than 0.25 mm did not attract any planulae. Red soil of larger particles did the same. A few particles smaller than the diameter of planulae aggregated to support one planula. Coral polyps were not able to reject red soil of less than 0.25 mm across, probably by acting as a barrier for gas exchange. The same reason may be applied to the inablity to attract plamulae settlement by this size particles.
|
