96 Lance W. Fontenot, Steven G. Platt, and Christine M. Dwyer 
in the predator’s stomach. This has been documented in crocodil- 
ians (Jackson et al. 1974, Garnett 1985), but evidence in snakes is 
lacking. The objectives of our paper are to provide data concerning 
field observations on the ingestion of crayfish by the green water 
snake (N. cyclopion) and to discuss the importance of crayfish in 
the diet of water snakes. 
STUDY AREA AND METHODS 
Observations of foraging snakes were made along Alligator Bayou, 
Ascension Parish, Louisiana. Alligator Bayou is in a swamp for- 
merly subjected to backwater flooding from the Mississippi River. 
Elevated areas in the swamp are dominated by bottomland hard- 
woods ( Quercus spp., Ulmus spp., Celtis laevigata , and Liquidam- 
bar styraciflua). Lower areas are dominated by Taxodium distichum, 
Nyssa sylvatica , N. aquatica, and Cephalanthus occidentalis. 
A 14-foot boat equipped with an outboard motor was used to 
search for snakes along waterways and canals. At night, a Q-beam R 
spotlight (250,000 candle power) was used to observe snakes. The 
stomach contents of snakes collected for a parasitological study were 
examined, and prey items were identified to the lowest possible 
taxon (Fontenot 1990). 
Crayfish are abundant at this site and are harvested commer- 
cially for human consumption. According to Huner (1975), red swamp 
crayfish (. Procambarus clarki) are most abundant during elevated 
water levels in the spring, when they mate. As water levels decline 
in the summer, the crayfish burrow down to the water level and 
remain below ground until water levels rise again in the late v/inter 
and early spring. 
RESULTS 
One male N. cyclopion (SVL = 50.1 cm, BM = 123.3 g) was 
observed foraging in relatively clear water at 2241 hours on 30 
May 1989. This snake slowly moved its head from side to side, 
while holding its jaws slightly agape in the characteristic foraging 
posture described for water snakes by Mushinsky (1987). The snake 
made contact with and immediately seized a red swamp crayfish, 
Procambarus clarki , (carapace length = 25.0 mm, total length = 
48.3 mm). The crayfish was molting; consequently, it did not pos- 
sess a hardened exoskeleton. The snake twisted its head and body 
during prey capture, positioned the crayfish in its mouth, and then 
ingested the prey tail-first within 30 seconds of capture. This posi- 
tion was later verified when the snake was dissected. Several uni- 
dentified small fish were also present in the gut contents. Both the 
