Abstract
| Original language | English |
|---|---|
| Article number | e2593 |
| Pages (from-to) | 1-22 |
| Number of pages | 22 |
| Journal | PEERJ |
| Volume | 2016 |
| Issue number | 10 |
| DOIs | |
| Publication status | Published - 2016 |
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Who's your mama? Riverine hybridisation of threatened freshwater trout cod and murray cod. / Couch, Alan J.; Unmack, Peter J.; Dyer, Fiona J.; Lintermans, Mark.
In: PEERJ, Vol. 2016, No. 10, e2593, 2016, p. 1-22.Research output: Contribution to journal › Article
TY - JOUR
T1 - Who's your mama? Riverine hybridisation of threatened freshwater trout cod and murray cod
AU - Couch, Alan J.
AU - Unmack, Peter J.
AU - Dyer, Fiona J.
AU - Lintermans, Mark
PY - 2016
Y1 - 2016
N2 - Rates of hybridization and introgression are increasing dramatically worldwide because of translocations, restocking of organisms and habitat modifications; thus, determining whether hybridization is occuring after reintroducing extirpated congeneric species is commensurately important for conservation. Restocking programs are sometimes criticized because of the genetic consequences of hatchery-bred fish breeding with wild populations. These concerns are important to conservation restocking programs, including those from the Australian freshwater fish family, Percichthyidae. Two of the better known Australian Percichthyidae are the Murray Cod, Maccullochella peelii and Trout Cod, Maccullochella macquariensis which were formerly widespread over the Murray Darling Basin. In much of the Murrumbidgee River, Trout Cod and Murray Cod were sympatric until the late 1970s when Trout Cod were extirpated. Here we use genetic single nucleotide polymorphism (SNP) data together with mitochondrial sequences to examine hybridization and introgression between Murray Cod and Trout Cod in the upper Murrumbidgee River and consider implications for restocking programs. We have confirmed restocked riverine Trout Cod reproducing, but only as inter-specific matings, in the wild. We detected hybrid Trout Cod-Murray Cod in the Upper Murrumbidgee, recording the first hybrid larvae in the wild. Although hybrid larvae, juveniles and adults have been recorded in hatcheries and impoundments, and hybrid adults have been recorded in rivers previously, this is the first time fertile F1 have been recorded in a wild riverine population. The F1 backcrosses with Murray cod have also been found to be fertile. All backcrosses noted were with pure Murray Cod. Such introgression has not been recorded previously in these two species, and the imbalance in hybridization direction may have important implications for restocking programs.
AB - Rates of hybridization and introgression are increasing dramatically worldwide because of translocations, restocking of organisms and habitat modifications; thus, determining whether hybridization is occuring after reintroducing extirpated congeneric species is commensurately important for conservation. Restocking programs are sometimes criticized because of the genetic consequences of hatchery-bred fish breeding with wild populations. These concerns are important to conservation restocking programs, including those from the Australian freshwater fish family, Percichthyidae. Two of the better known Australian Percichthyidae are the Murray Cod, Maccullochella peelii and Trout Cod, Maccullochella macquariensis which were formerly widespread over the Murray Darling Basin. In much of the Murrumbidgee River, Trout Cod and Murray Cod were sympatric until the late 1970s when Trout Cod were extirpated. Here we use genetic single nucleotide polymorphism (SNP) data together with mitochondrial sequences to examine hybridization and introgression between Murray Cod and Trout Cod in the upper Murrumbidgee River and consider implications for restocking programs. We have confirmed restocked riverine Trout Cod reproducing, but only as inter-specific matings, in the wild. We detected hybrid Trout Cod-Murray Cod in the Upper Murrumbidgee, recording the first hybrid larvae in the wild. Although hybrid larvae, juveniles and adults have been recorded in hatcheries and impoundments, and hybrid adults have been recorded in rivers previously, this is the first time fertile F1 have been recorded in a wild riverine population. The F1 backcrosses with Murray cod have also been found to be fertile. All backcrosses noted were with pure Murray Cod. Such introgression has not been recorded previously in these two species, and the imbalance in hybridization direction may have important implications for restocking programs.
KW - Conservation genetics
KW - Freshwater management
KW - Hybridisation
KW - Introgression
KW - Maccullochella
KW - Murray cod
KW - Murrumbidgee river
KW - Restocking
KW - Snps
KW - Trout cod
KW - Murrumbidgee River
KW - Trout Cod
KW - Murray Cod
KW - SNPs
UR - http://www.scopus.com/inward/record.url?scp=84994388380&partnerID=8YFLogxK
U2 - 10.7717/peerj.2593
DO - 10.7717/peerj.2593
M3 - Article
VL - 2016
SP - 1
EP - 22
JO - PEERJ
JF - PEERJ
SN - 2167-8359
IS - 10
M1 - e2593
ER -