The Influence of Light on the Number of Vertebrae in the Grunion, Leuresthes tenuis

The biology and use of zebrafish, Brachydanio rerio in fisheries research.

“…Attention has been given to the influence of light on meristic characters. Dannevig (1932) proposed that light might be a principal cause of vertebral variations and McHugh (1954) reported that an inverse relationship exists between light intensity and the number of vertebrae produced during embryonic development. The effect of the absence and presence of light upon the vertebral number of developing B. rerio embryos has been examined by Maginsky (1958) who showed a significant variation in the number of vertebrae and anal rays in zebrafish which developed in white light and darkness, respectively.…”

Causes and Significance of Morphological Variation in Fishes

“…Lindsey (1958) has suggested the northsouth clines may be induced by changes in the amount of light impinging on the eggs because this environmental parameter varies more regularly with latitude than does water temperature. Increased intensity (McHugh, 1954) and increased duration (Lindsey, 1958) of light caused the development of a lower number of vertebrae in two unrelated species of fishes. However, in these experiments many of the embryos died and selective mortality again may have been involved.…”

Population studies of Galaxias maculatus (Jenyns) (Osteichthys: Galaxiidae) in Chile with reference to the number of vertebrae

“…The variations within these specific ranges can be the result of the physical, chemical and biological character of the environment where eggs and larvae are found. The increase or decrease of the number of vertebrae are known experimentally to be caused by temperature (McHugh, 1954), light (Lindsey, 1958), salinity (Heuts, 1949), concentration of oxygen and carbon dioxide (Täning, 1952) and biological factors such as parasitic infections of the young (Hubbs, 1941).…”