Applied marine conservation genetics- CAPTIVE BREEDING PROGRAMMES

Question 1

Ultimate challenges of captive breeding programmes

Answer 1

maximise numbers and absolute genetic diversity, hybridise all subspecies (risk = outbreeding depression)

maximise genotype diversity & local adaptation, keep subspecies separate (risk= inbreeding depression)

Question 2

Outbreeding depression

Answer 2

the crossing of genetically differentiated populations can result in reduce population fitness

Question 3

Outbreeding depression in Oncorhynchus gorbuscha (Pink Salmon)

Answer 3

Adults migrate from Pacific ocean to home river and spawn two years after birth.

Spawn in odd OR even years = two broodlines/genetic populations.

In vitro crossing of populations resulted in 50% higher mortality in F2 hybrids.

Question 4

Inbreeding depression

Answer 4

the reduced survival and fertility of offspring of related individuals

Question 5

inbreeding depression in Phoca vitulina (Harbour Seals)

Answer 5

Correlation between:
helminth infection (bronchopneumonia)
and inbreeding level.

pup survival and inbreeding.

Question 6

3 primary goals of ex-situ breeding as part of a management or recovery program to conserve a particular species

Answer 6

1- Provide demographic and genetic support for wild populations
2- Establish sources for founding new populations in the wild
3- Prevent extinction of species that have no immediate chance of survival

Question 7

Broadcast Spawner

Answer 7

Fish which release their gametes into the water, where fertilization may occur; without parental care

Question 8

Problems with broadcast spawners in captive breeding programmes

Answer 8

May form a highly complex pedigree involving all possible crosses between a large number of males and females

Broadcast spawning has the potential to produce a very large population from only a limited number of parents.

ULTIMATELY PROBLEMATIC BECAUSE EFFECTIVE POPULATION SIZE MAY BE VERY SMALL DESPITE THERE BEING A LARGE CENSUS POPULATION SIZE

Question 9

Management actions to stop impacts on genetic diversity in wild populations

Answer 9

Banning releases of the alien
species.

Developing diagnostic tests for detection of hybrids in captive breeding programs.