Captive Care Notes: Lake Chub (Couesius, Family Cyprinidae)
Lake Chub (Couesius plumbeus) should only be maintained if the water can be kept cool, preferably lower than 21C (70F). The species has spawned in laboratory aquaria; unfortunately, the captive conditions under which it spawned were not reported. One condition, however, seems clear: prespawning males must experience a "winter" period in which temperatures drop to at least 12C (53.6F). According to a histological study conducted by Ahsan (1966), low winter temperatures prior to spawning are a major environmental factor in the production of Lake Chub sperm. Should the winter temperature remain higher than 16C (60.8F), sperm is produced either too early (before females are gravid) or not at all. Despite their nocturnal feeding habits in the wild, captive Lake Chub have no problem adjusting to a daytime schedule.