At the time of the spring tide (new moon and full moon), thousands of puffer fish around the world head for the coastlines to spawn. There, they gather at the water’s edge and vigorously tremble their bodies to spawn.

Scientists have long wondered how the puffer fish were able to synchronise their spawning with the lunar cycle.

A paper published in a recent issue of the Current Biology journal has the answers. 

Scientists have observed instances in which tuna rub themselves against the side of sharks. Apparently, they do this to dislodge painful parasites that cling to their head, eyes and gills.

“Shark skin is really smooth in one direction and it’s like sandpaper in the other,” said Chris Thompson, a Research Fellow at the University of Western Australia.

Thompson and his colleagues observed this behaviour after studying the footage of floating, baited underwater cameras which they had deployed in 36 regions in the Pacific, Indian and Atlantic Oceans in 2012 to 2019.

The 3.19 million barrels of crude oil that spilled into the Gulf of Mexico during the Deepwater Horizon in 2010 had a devastating impact to the natural environment, as well as the people and animals in the vicinity.

A study on the mahi-mahi in the nearby waters revisits the incident by studying how fish in the wild are being affected from the exposure to crude oil.

For more than a decade, some researchers in Australia have been monitoring coral reefs in the vicinity to see how rising ocean temperatures affect both the tropical and temperate reef fish communities.

The findings of their study was published in the Current Biology journal.

According to lead author Rick Stuart-Smith, a marine ecologist at the University of Tasmania, the team had focused on reef fishes as reefs provided many benefits to people and the fishes there helped maintain the natural ecological function of the reefs.

A study in the Proceedings of the Royal Society B Biological Sciences journal has found out that the ideal time for neon goby embryos to hatch is within two hours of sunrise.

For coral reef embryos, this knowledge is important as the time of their hatching is a perilous time that directly affects their survival. Yet many of them have to decide on their own when to hatch, according to corresponding author John Majoris, a research scientist at The University of Texas at Austin.

But not for neon goby embryos.

Like other fish, minnows can adjust their body temperatures to match that of their surroundings.

Research into the effects of climate change on fish generally focus on their heat tolerance at an increase of two or three degrees Celsius above the current average temperatures.

However, a recent University of Illinois study wanted to find out how fathead minnows handled short-term temperature spikes—those amounting to as much as 5 to 10 degrees Celsius above average.

They then followed the breeding of spiny chromis and discovered that 65 percent of nests on quieter reefs still had offspring at the season’s end, compared to 40 percent on reefs with a lot of motorboat traffic. On quieter reefs, offspring were larger, and each nest had more offspring by the end of the season.

Some juvenile fish on coral reefs exposed to motorboat noise have stunted growth and may be half as likely to survive as fish on quieter reefs, owing to the noise pollution altering their parents' caregiving behavior, said the researchers.