The following species were found at all or almost all of the flats surveyed by 

 the authors: 



Worms : 



Nemertea 

 Nematoda 



Gastropods: Hydrobia sp. 



Littorina littorea (common periwinkle) 



Bivalves: Macoma balthica (baltic clam) 



Mya arenaria (soft-shelled clam) 

 Mytilus edulis (blue mussel) 



Polychaetes: Eteone longa 



Nephtys caeca 

 Nereis virens (sandworm) 

 Heteromastus f iliformis 

 Polydora sp . 

 Streblospio benedicti 

 Scoloplos sp . 

 Tharyx acutus 

 Oligochaeta 



Crustaceans: Balanus balanoides (rock barnacle) 



Ampelisca abdita 

 Corophium volutator 

 Gamma rus mucronatus 

 Carcinus maenas (green crab) 



These species are present over the entire characterization area on mud flats 

 composed of different proportions of sand, silt, and clay. The more common 

 genera of the flats of Montsweag Bay (based on size, diversity, and frequency 

 of occurrence) are the polychaete, Heteromastus , the baltic clam, and the 

 polychaete, Scoloplos (Dean and Ewart 1978). The gastropod Hydrobia and the 

 polychaete Streblospio are dominant species listed by Dean and Ewart (1978). 

 Of 116 species collected on intertidal mud flats in the Sears Island area of 

 Penobscot Bay (region 4) the following species accounted for 73% of the total 

 (Normandeau Associates 1975): 



Gastropod 

 Rough periwinkle 

 Soft-shelled clam 

 Baltic clam 

 Polychaetes 



Hydrobia totteni 

 Littorina saxatilis 

 Mya arenaria 

 Macoma balthica 

 Heteromastus sp. 

 Tharyx sp. 



Of these species only the periwinkle was not reported by Larsen and Doggett 

 (1978a); the study by Normandeau Associates (1975) may have included a high 

 rocky intertidal area. 



Table 5-12 lists the 12 most abundant species found on mud flats in coastal 

 Maine by Larsen and Doggett (1978a). All but one, the gem clam, are found 

 characteristically on mud flats. Gem clams are high on the list in table 5- 

 12, mainly because of their abundance (up to 23,652 individuals/m ) at one 



5-105 



10-80 



