Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Fish Also Keep Watch

15.02.2018

Sentinel behaviour is found in the animal kingdom in species that live in communities such as marmots, meerkats, and birds. However, it has never been described for marine fish living in groups. Researchers at the Leibniz Centre for Tropical Marine Research (ZMT) have now found that coral reef fish also appear to show this behaviour. The study was published in the journal Environmental Biology of Fishes.

In the damselfish genus, there are species that live in close proximity to branching stone corals. They swarm around them and seek shelter between their branches as soon as danger threatens. The corals also benefit from their subtenants.


Damselfish of the genus Pomacentrus swarm around a branch coral, Indonesia

Photo: Robin Gauff, Leibniz Centre for Tropical Marine Research


Damselfish of the genus Pomacentrus seek shelter in a branch coral, Indonesia

Photo: Elyne Dugény, Leibniz Centre for Tropical Marine Research

Through their fanning behaviour, the damselfish ensure better water circulation as well as the supply and removal of oxygen. Hence, corals that live in a mutualistic relationship with damselfish can grow much faster.

Dr Sebastian Ferse, reef ecologist at the ZMT, and his team wanted to more closely investigate this symbiosis in lemon damselfish, shoal-forming reef fish of the species Pomacentrus moluccensis. They observed that the large, adult damselfish behave differently than the smaller, juvenile fish in case of danger.

In the area of the "Thousand Islands", which belongs to Indonesia, the researchers used underwater cameras in four different locations to film stone corals where reef fish were sheltering. In addition, they laid out pieces of dried squid as bait to attract predatory fish and also studied other factors that could threaten the damselfish.

The evaluation of the video material revealed that the fish perceived certain situations as particularly dangerous. The juvenile fish in particular disappeared deeper into the coral when the water was turbid and approaching predators such as snappers, groupers or angel fish could not be spotted immediately. While predators were close by, the adult fish positioned themselves relatively far away from the coral.

"With this behaviour, the larger lemon damselfish can better perceive their enemies. When a predator approaches, they pull back into the coral at lightning speed. As a result, they warn their inexperienced, smaller conspecifics," said Sebastian Ferse. The young fish sense the retreat of the big fish via their lateral line organ, with which they register water movements. The “sentinel fish” may also give alarm cues, as has already been proven with clownfish.

"Such selfless behaviour can only be explained by the fact that the members of a group are closely related," said Ferse. When reef fish spawn, the water flow drives the larvae away. However, the young damselfish have an amazing ability to find their way back to their original host coral. Thus, there may be close family ties between the inhabitants of a coral. Here molecular genetic investigations can provide information about the relationships.

Publication
Robin P.M.Gauff, Sonia Bejarano, Hawis H. Madduppa, Beginer Subhan, Elyne M.A. Dugény, Yuda A. Perdana, Sebastian C.A. Ferse: Influence of predation risk on the sheltering behaviour of the coral-dwelling damselfish, Pomacentrus moluccensis. Environmental Biology of Fishes (2018).

Contact
Dr. Sebastian Ferse
Leibniz Centre for Tropical Marine Research
email: sebastian.ferse@leibniz-zmt.de
Phone: +49 ()421 / 23800 - 28

About the Leibniz Centre for Tropical Marine Research
In research and education the Leibniz Centre for Tropical Marine Research (ZMT) in Bremen is dedicated to the better understanding of tropical coastal ecosystems. As an interdisciplinary Leibniz institute the ZMT conducts research on the structure and functioning of tropical coastal ecosystems and their reaction to natural changes and human interactions. It aims to provide a scientific basis for the protection and sustainable use of these ecosystems. The ZMT works in close cooperation with partners in the tropics, where it supports capacity building and the development of infrastructures in the area of sustainable coastal zone management. The ZMT is a member of the Leibniz Association.

Dr. Susanne Eickhoff | idw - Informationsdienst Wissenschaft
Further information:
http://www.leibniz-zmt.de

More articles from Life Sciences:

nachricht Nanobot pumps destroy nerve agents
21.08.2018 | American Chemical Society

nachricht How do muscles know what time it is?
21.08.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.

The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Biosensor allows real-time oxygen monitoring for 'organs-on-a-chip'

21.08.2018 | Medical Engineering

Researchers discover link between magnetic field strength and temperature

21.08.2018 | Physics and Astronomy

IHP technology ready for space flights

21.08.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>