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On the trail of strategic growth patterns of N. pulcher
Or: Why don‘t they grow?
N. pulcher group structure
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
• groups consist of a mixture between related and unrelated individuals.
• sexes don‘t change and are monomorphic• group structure is hierarchic mostly according to size
of the individuals• size increase from one individual to the next is usually
the body length of the smaller individual x 1.3
• breeders• sometimes also one breeding male and two breeding
females in the same territory (field)• helpers that defend territory (large)• helpers that care for the brood (small, rarer also large)• fry
The thing with growth is...
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
... whenever a hierarchically structured group shares a common habitat it‘s a source for competition and conflict.
• Control!
Examples for such conflicting growth patterns are:• strategic growth, gonadal growth, group size effects on growth
Strategic Growth
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
Is defined as:• a restricted growth within a socially structured
(mostly hierarchic) group, because of control by dominant individuals.
• a restricted growth because of ecological constraints.
• it can either be influenced • by any dominant (dominance effect)• only by dominats of the same sex as the affected
subordinate (queue effect)
Questions
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
• Is there strategic growth in N. Pulcher?
• If so, is there the same restriction for small and large helpers?
• Is there the same restriction for female and male helpers?
• What changes are there if the sex ratio of the helpers changes in a group?
Predictions
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
• Breeders tolerate a helper more readily when it is small (minimal size difference).
Predictions
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
• The larger a helper gets the more likely it is able to: • sneak spawn (as soon as it becomes fertile)
Predictions
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
• The larger a helper gets the more likely it is able to: • take over the territory
Predictions
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
• The larger a helper gets the more likely it is able to: • take over the territory
Predictions
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
• The larger a helper gets the more likely it is able to: • disperse
Predictions
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
• Also relatedness and as such the indirect fitness benefits of staying in a group should decrease with size.
This is not important for our experiment – our groups are artificial.
Large Helpers
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
Large Helpers:• pose a greater risk to breeders in general should
have more restricted growth than small ones
• large male helpers• should be more restricted in growth
• sneak spawn more easily than females
• are more likely to take over territories since there is only one dominant male per territory
• should be less restricted in growth because• the size distance to the male breeder and potential
competitor is larger than to the female breeder
• Females may lay larger clutches as appeasements to make the large helper stay
• male helpers disperse more
Large Helpers
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
• large female helpers• should show more restricted growth
• the size distance to the female breeder and potential competitor is less large than to the female breeder
• should show less restricted growth• since they cannot participate in sneak spawning as well
as males
• tolerated as secondary females in the territory
• Female helpers disperse less
Large Helpers
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
factor males femalessneak spawning risk high risk lower
territory take over risk higher risk lower
size difference (same sex breeder)
greater smaller
dispersal more less
other bf "peace eggs„ -
Small Helpers
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
Small Helpers:• do not pose such a great risk as large helpers
should not show as great a growth restriction• also there should not be a great difference between
females and males since• the conflict with the breeders isn‘t as pronounced
• selfish reproduction isn‘t as important with a smaller size
Set Up
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
large helper: male male female female
small helper: male female female male
Set Up
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
What we observed and measured:
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
Measured:• standard length, total length• DNA probes by fin clipping
• body mass
What we observed and measured:
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
Observed:• spawning (opportunistically)• interaction (3 to 5 days later)• "who is where and when"
• brood care (on the same day)
• brood care (much later)
Growth: overview
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
Blumberg: small helpers
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
males females
N = 48
N = 27N = 21
Blumberg: large helpers
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
males females
N = 48
N = 24N = 24
Conclusions: Blumberg
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
Small Helpers• no matter what the initial size, they always grow the same.
• no difference between males and females
There seems to be restriction when initial size is small!
Large helpers:• males seem to grow more when the initial size is larger
competition?
• females show pretty much normal growth
In theory...
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
In theory...
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
Queue
In theory...
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
Dominance
In theory...
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
Queue and Dominance
Queue or Dominance?
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
between sh and bf
N(m) = 21
N(f) = 27
N(m) = 21
N(f) = 27
N(m) = 21
N(f) = 27
between sh and bm
between sh and lh
Queue or Dominance?
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
between sh and lh
Queue or Dominance?
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
between sh and lh
Queue or Dominance?
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
between lh and bf
N(m) = 24
N(f) = 24
N(m) = 24
N(f) = 24
between lh and bm
Conclusions
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
Small Helpers• With the large helpers the situation is unclear (another
strange competition effect?)• the females seem to be the main cause
• with the breeders more or less the dominance situation
Large helpers:• again the females are showing this strange pattern...
helper females are a problem for the breeder female when they are small easily controlled when bigger then no control (because of intervention of
breeder males?)
Egg Cleaning and Fanning
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
Spawning
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
Sneak spawning was opportunistically done.• There was sneak spawning by both large and
small helper males. • Male sneak spawning occurred more often (Very
often in fact!).• Usually large helpers would do more sneak
spawning than the smaller ones.
So actually all is as predicted – except for large proportion of sneak spawning.
Questions
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
• Is N. pulcher able to assess relatedness? • How great is the acceptance of related helpers
compared to unrelated helpers of different sizes?
• Do fish grow more or less when they are related to the breeders?
• How great is the participation of brood care of a helper within a group when it’s related or not?
Predictions
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
Acceptance:• When breeders assess relatedness, related helpers are
more readily accepted.• related helpers also grow more
• Brood care:• Unrelated : there is more when "pay-to-stay“ is important
• Related: there is more when indrect fitness benefits etc. are important
General idea of this experiment:• Is it really relatedness that‘s important or is it rather more
recognition that will play a role?
known unknown
related natural artificial
unrelated semi-natural semi-natural
Rearing young
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
Set up
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion… related unrelated
Set up
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
Measured:• standard length, total length• DNA probes by fin clipping
• body mass
What I observed and measured:
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
Set up
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
Observed:3rd day after putting the breeders in• interaction • "who is where and when"
1 day after brood laying• brood care• interaction • "who is where and when"
3 days after brood laying• interaction • "who is where and when"
Results
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
The experiment is not yet finished.
No results are quantified yet!
Further discussion...
Introduction- N. pulcher
- About growth
- Questions
Queue- Predictions
- Set up
- Results
- Conclusions
Relatedness- Predictions
- Set up
Further
Discussion…
Feel free to ask questions!
