(Contribution from the Marine Laboratorj'", University of Miami) 



VARIATION OF GLYCOGEN Al^JD NITROGEN CONTENT 

 OF SHIPWORMS '/IT^ GROWTH AND SEASON-' 



by Leonard J, Greenfield 



Monthly analyses of the glycogen and nitrogen content of shipvirorms were 

 accomplished between July 195l and May 19^2. The above components were 

 selected as indices of stored protein and carbohydrate in the organising. 

 The average glycogen content of the shipworms over 2^ rag, dry weight was 

 found to be slightly above 30/o. From to 2^ mg, dry weight, a steady 

 increase in the percent concentration of this component was apparent. 

 Increasing nitrogen content vras observed in the smallest of the speci- 

 mens until a maximum value of 2,17-j occurred in the 10-lli.9 mg, weight 

 group. Sexual maturity of Teredo pedicellata was achieved in this 

 weight group under the conditions observed. 



No seasonal change in the nitrogen and glycogen content was noted, and 

 there was no apparent difference in the concentration of these components 

 betv/een gravid and non-gravid individuals of the same size range. 



A greater concentration of glycogen in the prenatal larvae than in the 

 free-swimming larvae viras recorded, and it was evident that a continued 

 free-living existence vrould deplete the supply of this material to a 

 minimum. This is based on the fact that liberated larvae do not feed 

 and are dependent on the glycogen reserves passively obtained from the 

 parent shipTJ-orm. Once attachment has taken place and feeding commences, 

 the reserve supply of carbohydrate needed for the resumption of metabolic 

 activity is replenished. 



The importance of v/ood used as a source of food in the diet of the organ- 

 ism vras also studied. In addition to wood polysaccharide utilization, 

 indications are that vrood contains sufficient nitrogen to account for 

 that found in Teredo pedicellata . Utilization of plankton as a source 

 of nitrogen viras also apparent. This v\ras demonstrated by growing the 

 shipworm in cellulose panels containing no nitrogen. 



-!}-Abstract of article from Dull, Mar. Sci. of the Gulf and Caribbean, 

 Vol 2, No. 3, pp, [i86-U96, March, 1953, 



P - 1 



