The reproductive performance of growth-enhanced transgenic and nontransgenic
coho salmon (Oncorhynchus kisutch) was examined to address concerns associated with
using genetically modified fish in aquaculture. A major concern is the initial
reproductive interaction between transgenic and wild fish that may occur if transgenic
salmon escape into the natural environment. This thesis attempted to obtain an indication
of reproductive allocation, effort and success for transgenic and nontransgenic salmon in
a simulated natural environment.
Several aspects of reproduction are examined for both transgenic and
nontransgenic fish to provide an indication of gamete quantity and quality, courtship
behaviour, spawning success, transgene transmission to offspring, and male competitive
ability. Female and male body size, shape, and gonadal somatic index (GSI) provided a
measure of phenotype and reproductive allocation. Female fecundity and egg diameter,
as well as male sperm production, fertility and competition examined gamete quantity
and quality. Female digging, probing, and covering, as well as male quivering examined
courtship behaviour of ovulated females and ripe males paired together in spawning
channels. Spawning success was recorded and fertilized eggs were collected and raised
to alevin in order to examine offspring viability. Polymerase chain reactions were
conducted on offspring blood samples to determine transgene transmission. Biting,
chasing and spawning success of male pairs placed together with an ovulated female
were analysed to determine male competitive interactions.
Results from these studies found several differences between transgenic and
nontransgenic fish. At maturation, transgenic males lacked red coloration and had a less
developed kype compared to nontransgenic fish, but no differences in male gamete
quantity or quality were observed. Transgenic females were more fecund than
nontransgenic females, but may have inferior quality gametes due to reduced egg size.
Transgenic females spawned less frequently and displayed consistently low levels of
courtship behaviour. No courtship behaviour differences between transgenic and
nontrangenic males were observed, however, during competition, transgenic males were
inferior; obtaining no spawnings, and displaying less courtship and competitive
behaviour. These studies are the first to show that in a simulated natural environment,
growth enhanced transgenic coho salmon display courtship behaviour and can spawn
producing viable transgenic offspring.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:BVAU.2429/14336 |
| Date | 11 1900 |
| Creators | Bessey, Cindy |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Relation | UBC Retrospective Theses Digitization Project [http://www.library.ubc.ca/archives/retro_theses/] |
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