Dependence of Visual Cues on Mate Selection in Cichlids

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Dependence of Visual Cues on Mate Selection in
Cichlids
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Why the heck I chose this topic. . .

• Cichlids are to my dad as Black-Capped Chickadees
  are to Dave

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So, whats the deal?

• Some species of cichlids thought to be extinct in
  the wild
• Why is this happening?
• Nile Perch
• Cichlids make a tasty dinner for Nile Perch
• Pollution
• Loss of Visual Cues
• Poor mate selection

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Cichlids and mate selection

• Sexual Selection
• Males
• Shouldnt stick around
• Should have courtship displays
• Be bigger and brighter (than females)
• Females
• Use visual cues to pick mates
• Dutch researcher, Martine Maan
• Female fish prefer brightly coloured males
• Easier to see
• In better shape
• Research on two similar species
• Best to pick bright coloured males
• Fewer parasites
• Adaptation to infection risks
• Stick to your own species!

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• Females actually don't need males to stick around
• Direct benefits of males are unlikely influence
  in female choice
• Bright colours may signal heritable quality

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Where the problem starts. . .

• Females usually like to stay within species for
  mating
• Closely related species
• Physically look different
• Differ little in ecology
• Live nearby
• In murky water, hard to distinguish
• Female discrimination can prevent hybridisation

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More evidence that they use visual cues

• Staged contest
• Under green light
• Coloration masked
• Red males dominate in white light
• Competitive advantage diminished in green light

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Conclusions

• Female choice
• Important factor in speciation
• When visual cues are blocked
• Murky water
• Wrong selection of mate
• Not choosing preferred males
• Hybridisation
• Resulting in possible total extinction of already
  dying species