? GEORGE V SESSIONAL PAPER No. 38a A. 1918 



IV 



NOTES ON THE HABITS AND DISTRIBUTION OF TEREDO NAVALIS ON THE 

 ATLANTIC COAST OF CANADA/ 



By E. M. Kindle, Ph. D., etc. 

 INTRODUCTION. 



A specimen of the boring work of the " ship worm," T. navalis was recently pre- 

 sented to the Museum of the Canadian Geological Survey by Mr. H. E. Miller, 

 accompanied by notes showing the dates within which the destructive work had been 

 accomplished. Although a considerable literature exists on the destructive work of 

 Teredo, records of its habits and work in Canadian waters are sufficiently scarce to 

 justify recording some of the interesting facts which have been communicated to the 

 writer by Mr. H. E. Miller. In the course of his work as an engineer in the Depart- 

 ment of Public Works in renewing wharves, piling, and other seashore structures in 

 Prince Edward Island, Mr. Miller has had unusual opportunities to become acquainted 

 with the work of the Teredo. The data relating to the habits of the boring mollusc, 

 popularly known as the ship worm, which are recorded in this paper have been sup- 

 idied chiefly by Mr. Miller. 



The distribution of Teredo navalis presents some novel features. It affords 

 an example of discontinuous distribution which parallels that of the common oyster 

 in Canadian waters. It is associated with the gulf of St. Lawrence colony of the 

 Acadian fauna, but its distribution varies rather widely, as will be pointed out, from 

 that of some of the other species of this northern Acadian colony. 



HABITS. 



Considerable human interest attaches to the boring work of the mollusc, Teredo 

 navalis, because it is equally capable of destroying wharves, or railway bridges, or 

 .^inking ships when precautions to check its ravages are neglected. The depredations 

 of Teredo are not confined to any particular parts of the world's coast lines. Its work 

 is well known on the Pacific coast, where the Isopod, Limnoria tenehrans, is locally 

 even more destructive.- In Europe the extraordinary increase in the numbers and 

 abundance of Teredo at various widely separated periods have several times brought 

 it into very prominent notice. During one of these periodic increases in its numbers 

 — about 1730-32 — ^Holland was imperilled by the threatened destruction of its sea 

 dykes.^ 



The rapidity with which timbers are frequently destroyed by Teredo navalis is 

 shown by the accompanying photograph (fig. 1) of a portion of a beech timber which 

 was 12 inches square when placed in the water. The timber was perfectly sound when 

 placed in the tidal zone just west of the entrance to Chariot tetown harbour. Prince 

 Edward Island. The completely honeycombed condition shown in the figure was 

 accomplished in a period of sixteen months. This is a much more rapid rate of 



1 Published with the permission of the Director of the Geological Survey. 



2 Harrington, N. R., and Griffln, B. B. Notes on the distribution and habits of some Puget 

 Sound Invertebrates. Trans., N.Y. Acad. Sci., 1897, pp. 158-9. 



3 Van Baumhauer, F. H. — The Teredo and its Depredations (translated from Archives of 

 Holland, Vol. I). Popular Science Monthly, Vol. XIIT, 1878, pp. 400-410. 545-558. 



93 



