TABLE 12. Estimated dates of peak abundance of larval winter flounder for each 

 developmental stage in the Niantic River and Day. 



developmental stage in the river and bay were 

 fairly consistent during the 5-year period. Stage 

 1 larvae generally peaked in early March, or in 

 1986, during late February. This corresponded 

 with the observations on spawning adult females 

 during the adult surveys. Based on water temper- 

 atures of 2 to 3°C during the latter portion of 

 February and egg incubation times reported by 

 Buckley (1982), peak spawning probably occurred 

 in mid-February. In the river, Stage 2 larvae 

 peaked in mid-March, but the dates of peak abun- 

 dance in the bay were 15 to 31 days later. As 

 noted in NUSCO (1987), the lag in peak abun- 

 dance of Stage 2 larvae in the bay may have been 

 related to flushing rate, because the average re- 

 tention time of a passive particle in the Niantic 

 River was reported as 25 to 27 days (Moore and 

 Marshall 1967; Kollmeyer 1972). In each year 

 the peak abundance dates for Stage 3 and 4 larvae 

 were very similar in both the river and bay. This 

 similarity, along with the lag in the date of peak 

 abundance for Stage 2 larvae, suggested that the 

 larvae were flushed from the river primarily during 

 that developmental stage. 



Predation could have affected larval abundance 

 and there are numerous accounts that jellyfish are 

 predators of fish larvae. Several species of 

 hydromedusae and the scyphomedusa Aurelia 

 aurila were found to prey upon herring larvae 

 (Arai and Hay 1982; Moller 1984). laboratory 

 studies with cod, plaice, and herring showed that 

 the capture success by A. aurelia increased with 

 mcdusal si7,e (Bailey and Batty 1984). Evidence 

 of a causal predator-prey relationship on larvae 

 of two European flatfishes [Pleuronectes platessa 

 and Plalichthys flesus) by A. aurita and the 

 ctenophore Pleurobrachia pileus was reported by 

 van der Veer (1985). Pearcy (1962) stated that 

 Sarsia tubulosa medusae were important predators 

 of larval winter flounder in the Mystic River, CT, 

 and had greatest impact on younger, less motile 

 individuals. Crawford and Carey (1985) reported 

 large numbers of the moon jelly {A. aurala) in 

 Point .ludith Pond, RI and felt that they were a 

 significant predator of larval winter flounder. The 

 medusae of the jellyfish Cyanea sp. has been sus- 

 pected of being an important predator of larval 

 winter flounder in the upper portion of the Niantic 

 River (NUSCO 1987). This hypothesized preda- 

 tion was based on data collected at station A 



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