Comparative analysis reveals use patterns of deeper Caribbean coral reefs by shark species

Group spawning may drive predator habitat use for lemon sharks, may inform fisheries management

Date: May 4, 2016

Source: PLOS

Three species of shark, tiger, lemon and Caribbean reef, all use deeper coral reefs in the Virgin Islands, but only lemon shark presence was associated with seasonal grouper spawning aggregations, according to a study published May 4, 2016 in the open-access journal PLOS ONE by Alexandria Pickard from Nova Southeastern University, Florida, Bradley Wetherbee of the University of Rhode Island and colleagues.

Groupers and other fish often spawn together in coral reefs at depths between 30 and 150 meters in the Caribbean, and these aggregations may make them easy pickings for predators. However, little is known about coral ecosystems at these depths when compared to shallow coral reefs. To quantify spatio-temporal patterns of reef use for three species of shark, the authors of this study analyzed data from acoustic transmitters placed on 18 sharks--6 lemon sharks, 10 tiger sharks, and 2 Caribbean reef sharks--that were tracked with acoustic receivers covering an area of more than 1,000 square kilometers near the island of St. Thomas.

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Lemon Sharks Return to Their Birthplace to Have Babies

By Megan Gannon, News Editor | December 05, 2013 10:35am ET

Female lemon sharks in the Bahamas seem to "remember" the place where they were born and return to the spot after years of wandering to give birth to their own young, a new study found.

This kind of homing behavior has been observed in other aquatic animals — salmon famously swim upstream to get back to their own spawning grounds and sea turtles return to the nesting beaches where they were born. After years of speculation, the researchers say this is the first time it's been confirmed that shark moms-to-be also go back to their own nurseries.

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Lemon sharks 'learn' skills by watching each other

Lemon sharks have the ability to learn from each other's behaviour, scientists have found.

The team compared the performance of inexperienced juvenile sharks working with both trained and untrained partners.

The results showed that sharks working with trained partners could complete tasks more quickly and successfully.

The study is thought to be the first to demonstrate social learning in any cartilaginous fish.

"I think it's a really cool finding," said lead author Dr Tristan Guttridge, director of the Bimini Biological Field Station in the Bahamas, whose paper was published in the Journal of Animal Cognition.

The results are a significant breakthrough, according to Dr Guttridge.

"It's a pretty exciting finding that these little lemon sharks are able to pick up social cues from each other," he said.

The evidence came from a task-based experiment with juvenile sharks conducted in an underwater pen.

Read on: http://www.bbc.co.uk/nature/19484530