The Journal of Heredity 73:310. 1982. Inheritance of shoulder spotting in the jewel tetra,

exhibit a relatively uniform body color without markings or with a prominent shoulder spot dorsal to the pectoral fins. Segregation patterns observed In the progenies from seven different matings Indicate a single-factor inheritance of shoulder spotting, with complete domi-nance of the spotted phenotype. FISHES in the teleost genus Hyphessobrycon exhibit a wide array of body colorations and markings1'4. Within the species complex of H. callistus, three subspecies are recognized, H. c. callistus, H. c. minor, and H. c. serpae. All three subspecies are easily maintained and hybridized in the laboratory. The two former subspecies closely resemble each other in size and coloration, differing phenotypically in markings immedi-ately dorsal to the pectoral fins. Characteristi-cally, H. c. callistus exhibits an elongated shoulder spot approximately 8 mm in length, whereas H. c. minor lacks this spotting pattern and displays only a uniform red body color. The present paper reports on the inheritance of the shoulder spotting pattern in H. callistus. Materials and Methods Healthy adults of H. c. callistus and H. c. minor were obtained from retail distributors and maintained in 5-gallon capacity stock tanks at 26 ° C. Reproductively mature pairs of both subspecies were selected at random and placed in separate 3-gallon capacity breeding tanks. All embryos were obtained from natural matings under procedures and conditions previously de-scribed2-3. Subsequent to each spawning, fertile eggs were incubated in tank water at 26°C. Dead or developmental ^ arrested embryos were re-moved daily. After hatching, fry from each mating were placed in separate holding tanks and permitted to develop until their body markings could be determined. Parentals of both sub-species, along with selected F|'s, were subse-quently used in a series of controlled matings; phenotypic data of progeny were recorded and subjected to chi-square analysis