So I asked leading shark ethologist and behaviourist, Professor Samuel 'doc' Gruber to elaborate. After pointing out how much pain women feel when they give birth, making the point that suffering has no effect on reproduction, he reminded me that sharks evolved their mating behaviours and the physical structures involved, separately from other animals.
The Angular roughshark (Oxynotus centrina) stands out with its unique, angular body shape that is unlike any other shark. Its body has a distinctive humped, almost pyramid-like appearance due to its high, triangular dorsal fins and compressed, thickset torso. The first dorsal fin, located just behind the head, is particularly tall and prominent, while the second is slightly smaller. These large fins give the shark its sharp-edged, almost boxy profile, which contrasts with the streamlined bodies of most other sharks.
The study, led by Michael J. Williamson, analysed data from over 700,000 shark detections across the Chagos Archipelago in the Indian Ocean between 2013 and 2020. It reveals that grey reef sharks are showing signs of distress. As coral ecosystems are impacted more and more by pollution and climate change, these sharks are reducing their time on the reefs. Instead, they are expanding their ranges and spending more time away from their ranges.
Researchers found the first evidence of a large shark killing a porbeagle shark, which can grow up to 12 feet long and weigh 500 pounds. Their study was published in the journal Frontiers in Marine Science.
The sightings, documented in a study by Amy Rose Coghlan and Naiti Morales, took place during a period of unusually warm sea surface temperatures, a condition that has been linked to the expansion of tiger shark habitats in other parts of the world.
The study, led by researcher Isabel Wagner, used a groundbreaking approach. They combined advanced genetic techniques (including target gene capture sequencing and whole-genome re-sequencing), to analyse the DNA of white sharks from across their global range. Eighty-nine individual sharks were examined through target gene capture sequencing, and 17 sharks were studied through whole-genome re-sequencing.
A new study has shed light on the surprising ways that the great sharks contribute to their ecosystems. They help transport nutrients across marine ecosystems, which involve a variety of marine life forms. As the climate warms and human activities continue to alter ocean conditions, their roles are shifting. Some species are expanding their ranges into cooler waters, affecting new areas and interactions.
During ten days of fieldwork in 2022 and 2023, the researchers caught ten sharks from the broadnose sevengill and the endangered soupfin species.
The Salish Sea separates northwest Washington from British Columbia's Vancouver Island. The 6,500-square-mile body of water stretches into Washington as Puget Sound, and the sharks were caught close to Olympia near the sound's southernmost point.
In an alarming discovery, researchers have found traces of cocaine in sharks off the coast of Brazil. This revelation underscores the far-reaching effects of drug pollution on marine ecosystems and raises significant concerns about the health of these apex predators.
The study describes how the researchers launched a drone from the beach and flew it to the site of a disturbance spotted from shore. Two basking sharks (Cetorhinus maximus) were immediately seen in close proximity—one near the bottom and one near the surface. The latter was confirmed to be a mature male due to the presence of claspers, while the shark near the bottom appeared to be a female.
Sharks first appeared in the fossil record about the same time that plants covered the land, nearly half a billion years ago. Evolution has made them so perfect that they have retained their main characteristics over all of this abyss of time. But despite their formidable lineage, modern sharks face unprecedented threats and challenges that endanger their diverse roles within ecosystems.
