yes lions are basicly nocternal hunters but they will eat what ever time of day food is offered I normally fed mine in the evening before bedtime roulghly 10:30 pm i feed every day.as silverslides can be part of a good diet for you lion make sure you give a variety of meaty foods such foods as squid ,shrimp, fish,krill .anything you can get him to eatof sw variety no fw feeders such as brine ,goldfish ect .even mysis if he will eat foods that small.I have house one of mine in a reef so it also shares space with many smaller fish that it could easily be called dinner,if i miss a feeding at any day I also lose a fish.they grow very quickly .but they are cool fish.good luck with your new arrival