SKELETAL EXTENSlON

摘要

Growth parameters (skeletal extension, density and calcification rate) were determined using annual growth bands along l2 slabs of skeletons of the reef building coral Montastraea annularis, collected at l.5 m depth in Puerto Morelos and at l0 m depth in Xahuayxol, in the Mexican Caribbean. X-radiography contact prints revealed that the high-density aunual growth band is formed during summer, possibly between July and September, when the sea water temperatures are highest in the Mexican Caribbean. Skel- etal extension, density and calcification rates obtained were within the range of values presented by other authors for M annularis in different reefs distributed throughout the Atlantic Ocean. Only slight trends could be identified for the time span represented by the slabs (l980--l995) for the three parameters, suggesting that the environmental condi- tions have been quite similar for the past l.5 decades. Using the available environmental data, it seems that, at least, water temperatures have been similar for the period of time studied in the two reef zones. In addition, the observed relationships among the growth parameters were similar to those previously described by other authors. An alternative to the more expensive density measurement procedures is described and discussed.