DISTRIBUTION OF HALOGENS IN THE HARD TISSUES OF POLYCHAETA
Okoshi, K.1 & Ishii, T.2
1Department of Biotechnology, Senshu University of Ishinomaki, Minamisakai, Ishinomaki, Miyagi 986-8580, Japan
2Division of Marine Radioecology, National Institute of Radiological Sciences, Isozaki, Hitachinaka, Ibaraki 311-1202, Japan
The polychaete worms have some hard tissues such as jaws, paragnaths, setae and articula. They are important morphological characteristics of the phylum Annelida. The jaws and paragnaths play a role of feeding. The prey is grasped with the jaws and is ground with the paragnaths, therefore, some means of hardening their structure is required. There is a few studies about the way of hardening and the chemical composition of these tissues. There are also a few reports of quantitative analysis of elemental composition for the hard tissue of polychaetes. To obtain basic information on the structural and compositional characters of the hard tissues of polychaetes, we have ray micro diffraction. We report the quantity and the detailed distribution of the major elements, especially halogens, concentrated in the hard tissues of nereid and polynoid polychaetes. This is also a first report on the chemical character of the hard tissues of the scale worm. The concentration of iodine and other elements in the hard tissues and in the whole body of four species of polychaetes are examined. A high accumulation of iodine appeared in the jaws of Perinereis aibuhitensis, Neanthes japonica and Halosydna brevisetosa. The iodine concentration in the jaws of these three species ranged from 12000 to 63000 ug/g on a dry weight basis. Whereas it was under the detection limit (10ppm for iodine) in the jaws of Marphysa sanguinea. Chlorine and bromine were also high in the nereid and polynoid species and were low in the eunicid one. Relatively high concentration (about 1% or higher) of zinc was observed in the nereid and polynoid jaws. In contrast, high calcium and phosphorus were observed in the eunicid jaws.