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ANALYSES
OF HARD TISSUE FORMATION BY FLUORESCENT SUBSTANCES IN CHITONS
Biomineralization
research is one of the more important research subjects from
both a fundamental and applied point of view. The molluscan
shells contain various information about their own growth
history including the continuous condition of mineralization and
stress or disease. Analysis of this information is a factor of
great importance in malacology. The application of fluorescent
substances to the analysis of growth performance and hard tissue
formation is popular in medical and dental sciences. The fish
otoliths also can be marked by immersion in some fluorescent
substances. The object of this study is to develop a method of
marking the valve (shell-plate), scale and spine of chitons with
fluorescent substances in order to obtain effective information
on growth.
To determine the optimum tetracycline(TC) and alizarine
complexone(ALC) concentration and treatment time for marking the
valve of chiton Acanthopleura
japonica, various combinations of concentration and
treatment time were tested. TC presented a clear yellow
fluorescent line in the dorso-ventral section of chiton valves
under UV light. The optimum condition for treatment was 200mg/l
for 12-24hr. Pink mark was observed by ALC treatment at 200mg/l
for 12-24hr. Double treatments by TC and by ALC were possible.
Similarity and difference of growth performance between the
valve and scale were also observed. Growth increments were also
observed both in valves and in scales. The number of growth
increments deposited between the fluorescent mark and the valve
edge was compared to the known time period the chiton was alive
since fluorescent mark induction.
Because
the treatment had no effect on the growth and survival of the
chiton, the application of the method to the marine mineralized
samples such as magnetic bacteria, coccolithophores,
reef-building corals and mollusks should promise the development
not only in malacology but also in marine biology. |
