Immigrant reproductive dysfunction facilitates ecological speciation

Area of Science:

• Ecology
• Evolutionary Biology
• Speciation Research

Background:

• Species distributions are shaped by survival and reproduction in new environments.
• Immigrant inviability is recognized, but immigrant reproductive success is less studied.
• Reproduction is a sensitive life-history stage potentially impacted in non-native habitats.

Purpose of the Study:

• To introduce and investigate "immigrant reproductive dysfunction" as a factor in reproductive isolation.
• To explore the role of natural selection on immigrant reproduction.
• To understand its implications for species distributions and speciation.

Main Methods:

• Conducted experiments on the sand goby (Pomatoschistus minutus), an externally fertilizing fish.
• Assessed adult growth and condition in non-native salinity.
• Measured sperm motility and hatching success in immigrant versus resident males.

Main Results:

• Adult sand gobies showed no significant changes in growth or condition in non-native salinity.
• Immigrant males exhibited reduced sperm motility and hatching success compared to residents.
• These findings suggest local adaptation or acclimation of reproductive traits.

Conclusions:

• "Immigrant reproductive dysfunction" is a potential mechanism of reproductive isolation.
• This dysfunction can reduce gene flow between populations.
• It may be a significant factor in shaping species distributions and driving speciation.