Aggressive Small Male Fish Protect Eggs

The journal PLoS ONE this month focuses on a tough little fish the 'Desert Goby,' that dwells in the deserts of central Australia. The study basically focuses on the aggressive mating behaviour of the smaller nest holding males.

Seems like these aggressive males have the 'Napoleon complex', named after the French general Napoleon Bonaparte. With adaptability to extreme climate these desert goby live in water twice as salty as the ocean and can withstand temperature alteration.

This novel finding was led by by Dr Andreas Svensson of Linnaeus University in Sweden in collaboration with Monash University and the University of Turku, Finland.

What is unique about this species is that the eggs are aggressively defended by the fathers. On getting a female counterpart back to his nest to lay her eggs, with the help of his pectoral fins he fans the eggs to keep them oxygenated.

What stunned the researchers was that difference in the behavior of the small nesting makes when compared to the larger males. To their surprise they found the small nesting males more aggressive towards intruders than larger males.

According to the study co-author Dr Bob Wong, a Senior Lecturer at Monash University's School of Biological Sciences and an expert in behavioral and evolutionary ecology, to attack early may be a beneficial strategy for small males, because they avoid revealing their inferiority to the intruder.

"In the animal world, competing males are expected to partake in a drawn out escalation of aggression, to avoid the risks of being injured by a superior opponent," Dr Wong said.

"We found the aggression of males was not affected by the presence of females and perceived mating opportunities or larger male intruders. Instead their aggression was related to their size.

"In particular, smaller males attacked sooner and with greater intensity compared to larger males, suggesting that nesting desert goby males used routine, rather than conditional, strategies for initiating aggression."

The research was presented at the International Behavioural Ecology Congress in Sweden in August 2012.