EHSE SPG| 14 March 2016 | Slide 1
Research Institute for the Environment and Livelihoods
Do fish vary their levels of parental care according to environmental
conditions?
Assoc Prof Alison King
Do fish vary their level of parental care according to environmental
conditions?
Assoc. Prof. Alison King & Prof. Jane Hughes
Parental care in fishes• Most fish broadcast their eggs
– No parental care
• Parental care
• PC increases offspring fitness & survival, but costs parental investment in other offspring (& themselves)
• PC investment may not be fixed, vary amount of PC– environmental condition,
– parents’ condition,
– and health of their young (Wootton and Smith 2015)
Guarding External bearing Internal bearing
Eggs
Southern pygmy perch (Photo: Hammer) Nursery fish (Figure: Berra) Poecilia reticulata(http://en.citizendium.org/wiki/Fish)
P.C. in Nthn Aust. freshwater fishes• Parental care unusually common N. A. fishes
– ~40%, compared to ~25% fish worldwide– Very little known life history
• Do P.C. fishes vary level of investment?– Environments Hyp: fish in riskier, ephemeral env’s have more eggs
– Determine their brood success (choose young)Hyp: fish in riskier, ephemeral env’s choose fittest young
Mouth almighty (Glossamia aprion)• Common, widespread, full range of habitats
• Male mouth broods eggs
• Kakadu billabongs (Bishop et al. 2001)
– ~300 eggs (n=3)
• Daly River (King pers. Obs).
– ~30 eggs (n=20)
• Marine relative ‘collects fitter’ young from multiple females
Specific Aims:(i) Whether egg number & quality are
higher in riskier, ephemeral habitats
(ii) Parentage pattern (Number of mums and dads to a clutch) varies across habitats
MethodsGenetics
• Genomic library needed
• Successfully developed primers 12 microsatellite loci; good to
excellent discrimination
• Paternity and maternity of each individual egg
Field collection
• Sampled mid-Daly River; Sept – Nov 2015River (8 sites) Billabongs (2 sites)
Ephemeral tributaries (3 sites)
Results: Field collection FAILED !• Many sites dry
• Already bred !
– Even in perennial
• Bred earlier - because it was such a dry year
• Only 1 mouth brooding male
• Pool in Ferguson River, ephemeral
• ~150 eggs
Conclusion• Continue into 2016 dry season
• So far, pattern still holding– >r eggs in riskier, ephemeral habitats
– ? Parentage patterns yet ?
• Important inclusion for ARC LP– Variability of life history traits in freshwater fishes across
hydrological conditions
