I have 6 in my fuge, had them about 6 months now. I hardly ever see them, what I do see is them blowing silt out of there foot/feeding tube which stick up through the sand. I dug one up this weekend and he quickly reburied himself. Do they help??
Little neck clams are found in waters all over the place, Here in NY the survive in freezing cold water in the winter and very warm water in the summer. In the shallow bays the water temp gets very warm. Same type of clam grows in Florida and all up and down the coast. So temp is not a issue with these guys IMO.