Karyological Analysis of Ctenopharyngodon idella, Aristichthys nobilis, and Their F₁Hybrid

Abstract

Ctenopha•yngodon idella (grass carp) and Aristichthys nobili,• (bighead carp) have a diploid chromosome number of 48 with no acrocentric chromosomes. The hybrid o1[' these species is triploid with 72 chromosomes. The frequencies of metacentric and submetacentric chromosomes suggest that the hybrid receives two maternal and one paternal set of' chromosomes. Crossbreeding experiments with cyprinids have resulted in the production of a number of viable hybrids (Aliev 1967; Andriyasheva 1968; Verigin et al. 1975; Bakos et al. 1978). Marianand Krasznai (1978) found that the intergener-8 43.3 SM 43.3 M 9 42.9 M 41.5 M 10 42.8 M 41.3 SM 11 42.4 SM 41.1 M 12 41.5 SM 41.0 M 13 41.1 M 40.0 .%M 14 39.9 SM 39.5 SM 15 39.9 M 39.4 M 16 39.5 SM 39.3 SM 17 39.1 M 37.5 M 18 38.4 M 37.5 M 19 36.3 36.7 M 20 36.0 SM 35.3 M 21 35.9 SM 34.5 M 22 35.0 SM 33.6 M 23 32.7 M 32.2 M 24 31.3 SM

Verification of the production of triploid grass carp(Ctenopharyngodon idella)with hydrostatic pressure

“…However, this method is time consuming and requires a high level of skill and adequate equipment; it also kills the fish and is not suitable for batch testing large numbers of animals. Hybrid grass carp X bighead carp, Hypophthalmichthys nobilis, is triploid with 72 chromosomes (Beck et al 1980). The three karyotypes which exceeded 60 chromosomes confirm triploidy measured by nuclear volume and flow cytometry for these three fish.…”

“…The production of sterile fish would overcome this problem. Artificially induced triploids of grass carp, salmonids, and other species of fish are regarded as sterile (Beck et al 1980;Thorgaard 1983;Allen et al 1986) because the odd number of chromosomes inhibits the development of the gonads or, when gametes do develop, the germ cells are aneuploid and not viable (Thorgaard 1983;McCarter 1987).…”

“…Triploids may be separated from diploids by karyotyping (Beck et al 1980;Cassani & Caton 1985), erythrocyte measurement (Beck & Biggers 1983), and flow cytometry (Allen & Stanley 1983). These techniques are unsuitable for testing large numbers of fish because of low accuracy, or time required per test, or the expense of test equipment.…”

Development and application of biological technologies in fish genetic breeding

“…Inter-familial hybridization has been reported between perciform cichlids O. aureus (♀) and Siniperca chuatsi (♂), with fingerling survival rates of 0.3%-0.5%, but this level is not adequate for production [59]. In contrast, the hybrid offspring of H. molitrix and Aristichys nobilis have higher survival and are less aggressive than their parents [60]. Similarly, the filial generations of O. mossambicus (♀) and O. niloticus (♂) have a faster growth rate than the parents [61].…”

Biology and management of grass carp (Ctenopharyngodon idella, Cyprinidae) for vegetation control: a North American perspective

“…According to Beck and Biggers (1980), hybrids they examined had no acrocentric (centromere near the end) chromosomes, and the frequencies of the metacentric (centromere in the centre) and submetacentric (centromere near the centre) chromosomes suggested that hybrids receive two maternal and one paternal set of chromosomes.…”