title: Hybrids between chum Oncorhynchus keta and pink Oncorhynchus gorbuscha salmon: age, growth and morphology and effects on salmon production.
abstract: Mature hybrids between chum salmon Oncorhynchus keta and pink salmon Oncorhynchus gorbuscha, which were identified by an intermediate colour pattern, were caught at the Kurilsky Hatchery, Iturup Island, Russia. Most of them were female and 3 years old (a partial freshwater year and 2 marine years), which is intermediate between the ages of maturity of the parental species. The hybrids exceed both parental species in the rate of growth, are large in size and robust and might successfully compete for mating in the wild or be chosen for artificial reproduction. The ratio of the scale length over width, R, is oblate (R < 1), whereas scales of the parental species are prolate (R > 1). From scale analyses, the c.v. in body size of hybrid females at the second marine year is twice that of O. keta, which suggests developmental instability in the hybrid. A dynamic model predicted that continuing hybridization at a low rate does not produce a substantial hybrid load due to selection against advanced-generation hybrids and backcrosses. A high hybridization rate, however, may be an additional risk for genetic management and should be taken into account in programmes of artificial reproduction of Pacific salmon Oncorhynchus spp., although such hybrids might have commercial use in confined production systems.
authors.affiliation: N.I. Vavilov Institute of General Genetics, Moscow, Russia. levazh@gmail.com.|VNIRO, The Federal Fishery Agency, Moscow, Russia. levazh@gmail.com.
authors.forename: L A
authors.initials: LA
authors.lastname: Zhivotovsky
authors.affiliation: VNIRO, The Federal Fishery Agency, Moscow, Russia.
authors.forename: T G
authors.initials: TG
authors.lastname: Tochilina
authors.affiliation: N.I. Vavilov Institute of General Genetics, Moscow, Russia.|Russian Scientific Center of Roentgenoradiology, Moscow, Russia.
authors.forename: E G
authors.initials: EG
authors.lastname: Shaikhaev
authors.affiliation: The Kurilsky Hatchery, Iturup Island, Kurilsk, Russia.
authors.forename: V P
authors.initials: VP
authors.lastname: Pogodin
authors.affiliation: N.I. Vavilov Institute of General Genetics, Moscow, Russia.
authors.forename: T V
authors.initials: TV
authors.lastname: Malinina
authors.affiliation: School of Fisheries and Ocean Sciences, University of Alaska Fairbanks, 17101 Point Lena Loop Rd, Juneau, AK 99801, U.S.A.
authors.forename: A J
authors.initials: AJ
authors.lastname: Gharrett
mesh_terms: D000818:Animals; D017756:Aquaculture; D005260:Female; D006824:Hybridization, Genetic; D008297:Male; D008957:Models, Genetic; D017683:Oncorhynchus; D017685:Oncorhynchus keta / Q000033:anatomy & histology / Q000235:genetics* / Q000254:growth & development; D010641:Phenotype; D012426:Russia; D012474:Salmon / Q000235:genetics
keywords: hatchery; interspecific characters; management production model; scale length; scale width