Hormones may help tiny African fish climb social ladder

Hormones may help tiny African fish climb social ladder
The small freshwater cichlid, native to east Africa's Lake Tanganyika.

Want to work your way up the corporate or social ladder?

You'll probably need to be a little aggressive, work hard and make lots of friends.

Surprisingly, things aren't that different for the tiny known as a cichlid.

Native to east Africa's Lake Tanganyika, live in complex social communities with strict hierarchies and rules. Those at the top of the social order are the only ones that breed, for example.

Cichlids even exhibit dominant and submissive behaviours in order to keep the peace and avoid fighting in the community.

"They're a remarkably social fish," says Adam Reddon, formerly a grad student in Sigal Balshine's Aquatic Behavioural Ecology lab, and now a postdoctoral fellow at McGill.

While at McMaster, Reddon and a team of researchers (collaborating with a team in Poland) studied the effects of two hormones – the fish versions of oxytocin and vasopressin – on the social behaviour of cichlids.

The hormones are important regulators of social behaviour in mammals, but little is known about their role in governing the behaviour of fish.

The researchers found that the hormones may in fact play a role in the complicated of cichlids, by impacting their aggressive and submissive actions and causing them to spend more or less time with other in their networks.

The work expands scientists' knowledge about cichlids' social structures, but it also helps them better understand the process of evolution.

"We're looking at the bigger picture and asking, 'What is evolution acting on?'" says Reddon. "How is selection working on ? It's about our fundamental understanding of animal populations."

The work was recently published in the journal Royal Society Open Science.


Explore further

Swimming with hormones: Researchers unravel ancient urges that drive social decisions of fish

More information: "Brain nonapeptide levels are related to social status and affiliative behaviour in a cooperatively breeding cichlid fish." R. Soc. open sci.: 2015 2 140072; DOI: 10.1098/rsos.140072. Published 4 February 2015
Journal information: Royal Society Open Science

Citation: Hormones may help tiny African fish climb social ladder (2015, February 16) retrieved 22 August 2019 from https://phys.org/news/2015-02-hormones-tiny-african-fish-climb.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
40 shares

Feedback to editors

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more