began a study to determine the concentrations 

 of iron, manganese, and zinc in several spe- 

 cies of polychaetes and to examine the influence 

 of feeding habits and geographical location on 

 these elemental concentrations. This study is 

 part of a larger program currently underway 

 at our laboratory in which we are following 

 the movement of iron, manganese, and zinc in 

 sediments, water, and biota within a shallow 

 estuary. 



Methods 



Collections of polychaetes were made every 

 2 months from June 1967 through March 1968 

 from five stations--two in the Newport River 

 estuary and three in Bogue Sound adjacent to 

 the estuary. Polychaetes were collected from 

 tidal flats exposed during low tide. A shovel 

 was used to dig out a portion of the sediment, 

 and each shovelful was carefully broken open 

 by hand in search of polychaetes. All poly- 

 chaetes collected were rinsed carefully to 

 remove sediment adhering to body surfaces 

 and were placed in plastic bags according to 

 species. No broken or bleeding polychaetes 

 were kept. 



In the laboratory, each worm was rinsed 

 again in salt water, blotted with an absorbent 

 napkin, and placed in a beaker. Each sample 

 consisted of about 10 worms (with the exception 

 of Chaetopterus which were analyzed individ- 

 ually). The samples then were weighed, dried 

 at 90° C. for 48 hours, and weighed again. 

 Each sample was dissolved in concentrated 

 nitric acid and evaporated to dryness on a hot- 

 plate. The residue was redissolved in 0.25 N 

 HCl to a constant volume and filtered with 

 Whatman No. 42 filter paper. The filtrate then 

 was analyzed for concentrations of iron, man- 

 ganese, and zinc by atomic absorption spectro- 

 photometry. 



Ecology of Species Collected 



Of the seven species of polychaetes col- 

 lected, three can be classified as surface 

 feeders and four as subsurface feeders. A 

 brief description of distribution and feeding 

 habits, if known, follows: 



Amphitrite ornata is a ciliary feeder that 

 collects detritus from the surface of the sedi- 

 ment by means of contractile tentacles. This 

 species, which constructs a muddy cylindrical 

 tube, was present at four of our collecting 

 stations. 



Diopatra cuprea is reported to be carnivorous 

 and constructs a tough chitinized tube that 

 extends vertically into the sediment. The open- 

 ing of the tube is camouflaged with debris such 

 as seaweed, pieces of shell, etc. This species 

 catches small organisms as they pass by the 

 opening of the tube. The polychaete is the most 



abundant species collected and was present at 

 four stations. 



Chaetopterus variopedatus , (fanworm) like 

 A. ornata, is a ciliary feeder except that it 

 constructs a U-shaped parchment tube and 

 uses parapodia to produce a current of water 

 which flows through the tube. It filters out 

 plankton and detritus from the water through 

 a mucus bag that is then ingested. This species 

 was not abundant near our stations --only five 

 individuals were found. 



Glycera dibranchiata (bloodworm) is a sub- 

 surface feeder that has been reported to be both 

 a carnivore and a detritus feeder. A small 

 fishery for G. dibranchiata exists along the 

 coasts of Maine and Nova Scotia as the worm 

 is valued as bait for sport fishermen. This 

 species was collected from four stations and 

 almost consistently from the anaerobic portion 

 of the sediment. 



Arabella iricolor was collected from only 

 one station and is probably a detritus feeder. 

 Like G. dibranchiata , it is found in the anaero- 

 bic zone. 



Nereis sp. (clamworm) is a subsurface 

 feeder whose abundance fluctuated markedly 

 throughout the study. A conflict exists in the 

 literature as to whether members of this genus 

 are carnivores, detritus feeders, orboth. 



Marphysa sp. was fo\ind just beneath the 

 sediment surface and at depth. It was present 

 at only one station that had a large oyster 

 population and was collected from sediment 

 just beneath the oyster shells. The food habits 

 of this species are not known although the 

 structure of the mouth parts suggests that it 

 may be a carnivore. 



Elemental Concentrations 



The concentrations of zinc, manganese, and 

 iron in the seven species of polychaetes col- 

 lected varies with element and species (table 3). 

 Iron is most abundant in these worms, followed 

 by zinc and then manganese. Glycera and 

 Arabella , two subsurface feeders, have the 

 highest values of zinc and lowest values of 

 manganese and iron. Chaetopterus has the 

 greatest concentrations of manganese and iron. 

 Nereis, Amphitrite , and Marphysa also con- 

 centrated more iron than Glycera , Arabella , 

 or Diopatra. Standard deviations ranged from 

 ±20 percent for the concentrations of man- 

 ganese in Nereis to ± 58 percent for concen- 

 trations of the same element in Chaetopterus . 

 The magnitude of these variations requires 

 that many samples be collected for analyses. 



Effect of Geographical Location 



The routine collection of Amphitrite , Dio- 

 patra, and ^Glycera from four stations within 

 our sampling area permitted study of the effect 



32 



