2 indicated that the younger larvae were greatly undersampled . Steige 2 

 larvae were more evenly dispersed throughout Niantic River and Bay. The 

 frequency of Stage 3 larvae, low in the mid and upper river, was high at 

 station C and at NB and EN in Niantic Bay, Stage 4 frequency was 

 highest at C and in Niantic Bay with EN having a greater frequency than 

 NB. At all stations an approximate six to ten-fold reduction in 

 frequency occurred from Stages 4 to 5; most were collected at EN. This 

 reduction was expected due to the predominantly benthlc habits of the 

 later developmental stages. The spatial distribution of developmental 

 stages agreed with patterns of larval abundance noted above, with early 

 stages found in the mid and upper river and later stages concentrated in 

 the lower river and Niantic Bay. 



Larval frequencies in day and night collections were examined by 

 developmental stage and station (Fig. 10). No apparent differences were 

 found for Stages 1 and 2. For Stages 3 and 4, frequencies were higher 

 during the night than the day at stations B, NB, and EN, but not at C. 

 Frequencies of Stage 5 larvae were higher during night at all stations. 

 Previously, this diel difference in larval abundance had been attributed 

 to vertical movement of larvae from on or near bottom into the water 

 column at night (NUSCo 1983) . The lack of diel vertical movement of 

 Stage 3 and 4 larvae at station C suggested that other factors in the 

 lower river must have affected their behavior. 



A comparison of the temporal distribution of developmental stages 

 in the Niantic River and Bay was made by examining the cumulative 

 percentage of each stage over time (Fig. 11). Stage 1 larvae in the 

 Niantic River were collected in fairly consistent densities throughout 

 March, as indicated by the linearity of the cumulative percent curve, 

 and then declined at the end of the month. Data for this stage was not 

 plotted for Niantic Bay because so few were collected. In the Niantic 

 River, most of the Stage 2 larvae were collected from March to 

 mid-April. In Niantic Bay, Stage 2 larvae were abundant from April 

 through May. Stage 3 larvae were abundant in the river and bay from 

 mid-April to mid-May. Stage 4 larvae increased in abundance during the 

 last week of April at both locations and declined in the river during 

 mid-May and in the bay during late May. The cumulative percent curve of 

 Stage 5 larvae was more erratic, probably due to low collection 



35 



