8-34 



CO ivably excavated in an attempt to avoid intolerably low water temper- 

 atures (<5°C) (McCluskey, 1977) . Laboratory observations have shown 

 that individuals without burrows die when exposed to water temperatures 

 of 5°C; while individuals within burrows survive temperatures to 0°C 

 (McCluskey, 1977) . Except during winter, when Sguilla is inactive and 

 deep in its burrow, it spends much time at the entrance to its burrow in 

 wait of prey (Caldwell and Dingle, 1976) . 



In New Haven Harbor, the abundance of Sguilla as determined by 

 trawl sampling is highly seasonal (Figure 8-9) . Peak abtindances were 

 observed during September, October and November coincident with declining 

 seasonal temperature maxima. During the remainder of the year abundances 

 were extremely low. It is not clear why the Sguilla catches peak in 

 abundance during the fall, but it may be related to mating (occurring 

 out of the burrow) or possibly its change from summer to winter burrow. 

 This is supported by the fact that increased epibenthic activity of 

 Sguilla during October and November is also reflected in the 1976 impinge- 

 ment data from Port Jefferson and Glenwood, as well as the New Haven 

 Harbor Station impingement data for August 1975 through October 1977. 

 As in otter trawl samples, Sguilla was found impinged in highest abun- 

 dances during October and November, and in low abundances during the 

 remainder of the year. 



On an annual basis, Sguilla was typically collected in low 

 numbers. Sguilla ranked 8th in overall abundance from 1974 through 1977 

 comprising less than 0.1 percent to 0.6 percent of the total catch 

 (Table 8-4) . Sguilla was found in highest abundances at Stations 8 and 

 11 (Table 8-3) . Because of its burrowing behavior, abundance is to a 

 large degree related to suitable habitat. Sguilla is typically found 

 on silty/clay or muddy bottoms where burrows can easily be excavated 

 (Gosner, 1971) . Based on benthic grab samples taken in the main channel 

 in tho vicinity of the Harbor Station discharge and middle harbor region 

 (NAl, 1078a), as well as analysis of marine sediments adjacent to the 

 New Haven Harbor Station (NAI, 1972) , black to gray marine mud is pre- 

 dominant in this area. This type of sediment permits the excavation of 

 deep burrows essential for winter survival of Sguilla. 



