EXPERIMENTAL FISH EMBRYOLOGY ii09 



BECORD OF EMBRYONIC INIXTCTIONS IN FISH 



THE GENETICS OF FISH* 



Through an Intenaive series of researches Gordon (1927-19'*8) has demonstrated that 

 the mechanism of inheritance la essentially Mendellan for fishes, as It has heen proven 

 to he for all other groups studied. There are wild types (gray) of the Platy (Platy- 

 poecilus maculatus) and domesticated albino and golden types which can he interbred 

 readily. In all, there are some 150 varieties of patterns in this one species, relative- 

 ly few of which have, as yet, been thoroughly analysed from a genetic point of view. Ee- 

 cently (l^^k-V^kQ) Dr. Gordon has concentrated on the inheritance of melanomas, which 

 study is closely akin to cancer studies on higher forma. 



The Platy Is readily available at any Aquarium Supply Houae, and the three major 

 varieties (wild, albino, and golden) may be procured for simple genetic crosaes. The 

 golden mutant arose from a wild atock in I92I and the albino appeared first, also from a 

 wild stock, in 195*+ • When these mutanta are Interbred, the wild variety re-appears- 



Following are a aeries of genetic croasea that have been made by Dr. Gkirdon, indicat- 

 ing clear-cut dominance and recesalveneas of various pigment patterns. These are offered 

 here as suggestive of the type of study in the field of developmental heredity that is now 

 possible. (See also papers by Goodrich et al.) 



* These figures are kindly loaned by Dr. l^ron Gordon of the New York Zoological Society. 

 It is hoped that Dr. Gordon will aoon make available, in concentrated form, his knowl- 

 edge of the Genetics of Fishes. 



