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.
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.
Having photographed most of the sharks and rays that can be seen on scuba around the world, Andy Murch is doggedly pursuing the remaining few. Recently, his elasmobranch obsession took him to Papua New Guinea, where he hoped to find three endemic species of epaulette sharks.
Steven Minaglia, a faculty member from the University of Hawaiʻi with a passion for channel swimming has published a study that sheds light on the rare interactions between cookiecutter sharks (Isistius brasiliensis) and humans. Minaglia is an associate professor of obstetrics, gynaecology, and women’s health at the John A. Burns School of Medicine, and reveals how environmental factors can elevate the chances of being bitten.
The study, spanning 66 marine reserves across 37 countries worldwide, sheds light on the stark contrast in shark abundance between fully protected zones and areas open to industrial fishing. Reef-dwelling species such as Caribbean reef, grey reef, whitetip reef, and nurse sharks exhibited nearly double the population density within fully protected marine reserves compared to fishing-permitted zones.
The debate surrounding the stability of South Africa's white shark population has intensified. A rebuttal article raises concerns about the validity of the claims raised in a recent academic article about white shark population stability and the potential implications for conservation efforts.
A recent article by Sam Fletcher begins with the gripping account of a wildlife videographer, Scott Fairchild. Using a drone, he captures a heart-stopping moment when a great white shark repeatedly approaches a lone swimmer off the coast of San Diego. Yet suddenly the shark veers away and disappears. Fairchild states that he has seen countless such encounters between swimmers and white sharks off the Californian coast.
For fish and other water-breathing animals like sharks and rays, reaching reproductive maturity is a crucial milestone that impacts their entire life history. The size at which they reach maturity, coupled with their subsequent growth rate, affects their longevity and reproductive capacity. Now, researchers have pinpointed a specific pH threshold, termed the "reproductive respiration threshold" (RRT), which kickstarts the hormonal processes leading to maturation.
Unveiled by an international team of archaeologists and palaeontologists, this finding provides an intriguing glimpse into the ancient seas and the life of a previously unknown apex predator of the Late Cretaceous period.
