Monogamy in a Hyper-Symbiotic Shrimp

Area of Science:

• Marine Biology
• Behavioral Ecology
• Symbiosis

Background:

• Monogamy is theorized to be adaptive for symbiotic crustaceans in specific environments.
• Resource-specialist symbionts in simple tropical hosts face high predation risk.
• Pontonia manningi shrimp live within the Atlantic winged oyster, Pteria colymbus.

Purpose of the Study:

• To test the prediction that monogamy is adaptive for Pontonia manningi.
• To investigate the mating system of P. manningi in its natural Caribbean habitat.
• To analyze factors influencing pair-bonding and potential promiscuity in this shrimp species.

Main Methods:

• Field observations of Pontonia manningi within Pteria colymbus hosts.
• Analysis of shrimp distribution, pairing behavior, and sexual dimorphism.
• Assessment of female reproductive status and male claw morphology.

Main Results:

• Pontonia manningi were found in heterosexual pairs more often than expected by chance.
• Males and females occupied the same host regardless of female reproductive stage.
• Evidence suggests male promiscuity, indicated by solitary brooding females and larger male claws.

Conclusions:

• The mating system of P. manningi is predominantly monogamous, aligning with theoretical predictions.
• Male P. manningi exhibit moderate promiscuity, potentially engaging in mate-searching and competition.
• The complex mating system reflects a balance between host-dwelling stability and male reproductive strategies.