Fish

Chromis viridis (green chromis) is a species of damselfish.

Fish trust friends in a crisis

In social animals living in the wild, individuals rely on their buddies to alert them if a predator is lurking.

All animals aim to balance the risk of predation against the energy investment necessary to execute an escape, to maximise the number of correct reactions (e.g. reacting to the presence of a predator) and minimise reactions to inaccurate information (e.g. reacting to harmless stimuli).

Trust among individuals is critical. This is true for humans as well as many other species, including fishes.

Study co-author Jacob Johansen, Ph.D.

Researchers studied more than 200 marine fish species before coming up with their findings.
Researchers studied more than 200 marine fish species before coming up with their findings.

Baby reef fishes take the gold

A study has shown that baby reef fishes clock in at 15 to 40 body lengths per second, making them one of the fastest youngsters around.

In contrast, baby herring swim up to two body lengths per second, while the fastest human (Olympic gold medallist Michael Phelps) manages just 1.4 body lengths per second.

So how did those tiny baby reef fishes get to be so fast so early in their lives?

Juvenile clownfish exposed to artificial light at night die sooner than those exposed to natural light at night.
Juvenile clownfish exposed to artificial light at night die sooner than those exposed to natural light at night.

No artificial lights for Nemo, please!

Scientists have discovered that clownfish living closer to shore die sooner than their counterparts found farther offshore due to the difference in the amount of artificial-light exposure.

The more artificial light they were exposed to, the higher the mortality rate.

The study focused on the reefs around Moorea in French Polynesia. It involved exposing 42 juvenile clownfish to either artificial light at night (ALAN) or natural light (meaning, moonlight!) in the lagoon. Each of the 42 territories had a magnificent sea anemone.

Clownfish at different anemones get stripes at different rates

Scientists have discovered that how fast the white stripes that run down the clownfish’s body develop depends on the sea anemone it lives in.

Specifically, they found out that the clownfish living in the giant carpet anemone and those living in the magnificent sea anemone develop stripe patterns (called “bars”) at different speeds as they matured from the larval to the adult stage.

Lionfish, native to the Indo-Pacific, is characterized by conspicuous warning coloration and venomous spiky fin rays.

Stung divers needed for Lionfish Pain Survey

The two Canadian universities are currently collaborating on the world's first large-scale study of lionfish stings. At present, there is no scientific data that has been collected on a broad scale, as to what happens to a human after they have been stung by a lionfish. 

Subject Criteria

Been stung? The scientists would like to collect the pain and symptoms you experienced after you were stung.  

Individual fish can be identified based on their behaviour and movements
Individual fish can be identified based on their behaviour and movements

Fish in study can be identified based on their movement and behaviour

This finding was based on research by a team of biologists and mathematicians from Swansea University and the University of Essex. It involved 15 three-spined stickleback fish observed individually in a fish tank containing two, three or five plants in fixed positions.

Fish larvae
Fish larvae

Research shows reef fish larvae dispersed differently

Coral reef fish start their lives as small, transparent larvae. After they hatch, they join a swirling sea of plankton and frequently get dispersed to different reefs due to ocean currents, waves and the wind.

In this study, the scientists did seven years of surveys focussing on the Clark’s anemonefish, measuring how the dispersal of larvae varied over the years and seasonally. They discovered that the larvae dispersal varied immensely on both these timescales.

Previous studies of shipwrecks in the United Kingdom and the Red Sea have shown that such artificial reefs often create new and different types of habitat than natural reefs.

Fish thrive on WWII shipwrecks

In 2016, the National Oceanic and Atmospheric Administration (NOAA) undertook a closer examination of the wrecks of the German U-boat U-576 and the Nicaraguan freighter SS Bluefields, using glass-domed submersibles. The two historically significant and deep (200m) shipwrecks sank near one another on the continental shelf of North Carolina, USA, during World War II.

The Fabulous Spawning Ritual of Striated Surgeonfish

Schooling striated surgeonfish

During a seven-year study of reef sharks in Tahiti, ethologist Ila France Porcher also observed the behaviours of various fish species. Here, she offers a detailed description and insights into the dynamic and mesmerising spawning events of the striated surgeonfish, which take place every year in the South Pacific.