Sthenolepis areolata

Our planet’s <a href="https://www.earth.com/news/earths-oceans-are-on-track-for-a-catastrophic-extinction-event/">oceans</a> are home to some of the most diverse and complex ecosystems. However, warming temperatures are causing increasingly more marine organisms, including corals, to die out. A new study led by <a href="https://www.osu.edu/">Ohio State University</a> (OSU) has advocated the use of mesoscale sanctuaries – areas that can stretch for thousands of miles, often across national boundaries – to protect the over 6,000 coral species populating the oceans.



“Coral reefs are an essential ecosystem on our planet,” said study co-author Andrea Grottoli, a professor of Earth Sciences at OSU. Although they occupy less than 0.1 percent of the surface area in the Earth’s oceans, over 30 percent of all aquatic creatures depend on them.&nbsp;



Reef ecosystems are really important for humans too, explained Grottolli, “in that they provide protection to coastlines from erosion and storms, and they’re essential for certain services like tourism and other parts of the economy.”&nbsp;



Due to rising sea temperatures, reefs all over the world are experiencing higher rates of bleaching – a phenomenon during which corals’ skeletons become visible, turning them into a faded, ghostly white. Although bleached corals are not yet dead, mass bleaching events are an indicator of an ecosystem’s declining health, and often lead to mass mortality across marine species.



Yet, even if the global population of coral dwindles, the genetic diversity of coral species helps ensure that at least some of them may be able to adapt and recover.&nbsp;



While longer-term measures to mitigate climate change include curbing greenhouse gas emissions, the study suggests that, in the meanwhile, broad transdisciplinary approaches to creating both local and large-scale ocean sanctuaries that trespass national boundaries are urgently needed.&nbsp;



“Global warming is the No. 1 threat to coral reefs right now,“ Professor Grottoli warned. “So when we think about coral reef conservation, we can't limit ourselves to arbitrary geographic boundaries.”



Moreover, education is a highly important tool in the efforts to protect coral reefs. “People who understand coral reefs, and who understand the value of coral reefs, are much more likely to do something to help protect them,” Professor Grottoli concluded. “If you don’t know anything about coral, and you’ve never seen one, how can you have any empathy or feel any connection to that ecosystem?”&nbsp;



The study is published in the journal <a href="https://onlinelibrary.wiley.com/doi/10.1111/gcb.16192">Global Change Biology</a>. In addition, a list of individual actions individuals can take to protect these endangered ecosystems can be found <a href="http://coralreefs.org/pledge-4-reefs/">here</a>.



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Large-scale ocean sanctuaries needed to protect corals

Our planet’s oceans are home to some of the most...

There are 16 species of beaked whales in the genus Mesoplodon, making this the largest cetacean genus. The habits of most of these <a href="https://www.earth.com/news/invasive-species-are-transforming-coastal-estuaries/">species</a> are largely unknown because the whales are shy, slow-moving and difficult to observe. In fact, some types of beaked whales are only known from dead specimens that have washed ashore.&nbsp;



Mesoplodont whales represent one of the least studied mammalian groups, as evidenced by the fact that three new species have been identified in the past 30 years. The most recent of those species, Ramari’s beaked whale (M. eueu), was described to science just last year.&nbsp;



The beaked whales all tend to have spindle-shaped bodies and small dorsal fins, making the species difficult to tell apart in the field. Also, since they often occur in the same areas and forage at similar depths, they are thought to compete with one another for the same prey items – deep sea squid and small fish. Closely related species usually show different foraging strategies, reflecting the evolutionary drive to optimize foraging performance and minimize interspecific competition. However, this does not seem to be the case amongst this group of closely related beaked whales.&nbsp;



Individuals from some species have been fitted with biologgers, attached to their backs with suction-cups, and the data recorded by these devices has given a glimpse into the underwater lives of these whales. Typically, beaked whales have a low-energy lifestyle. They swim slowly and perform extreme deep dives using an energy-conserving swim-style. They hunt for prey in the ocean depths and can remain underwater for up to an hour.&nbsp;



Sowerby’s beaked whale (Mesoplodon bidens), described in 1804, was the first of these small cetacean species to be identified. But because the species is retiring, seldom observed and lives in open ocean areas, little is known about its behavior. Until recently, individuals from this species had not been fitted with biologgers. However, after years of effort, scientists have now been able to attach the tracking devices to two of these whales and the data has revealed some surprises.&nbsp;



The international team of biologists, led by Fleur Visser of the <a href="https://www.uva.nl/en">University of Amsterdam</a> (UvA) and the Royal Netherlands Institute for Sea Research (NIOZ), received data from the biologging tags that revealed the diving, movement and echolocation strategies of these whales. The results, published recently in the&nbsp;<a href="https://journals.biologists.com/jeb/article/225/9/jeb243728/275372/Sowerby-s-beaked-whale-biosonar-and-movement">Journal of Experimental Biology</a>, showed that Sowerby’s beaked whales actually move around and hunt much faster than other, related species.&nbsp;



When the researchers compared the biologger data for the two Sowerby’s beaked whales with that from the closely related Blainville’s beaked whale, they found that the Sowerby’s whales consistently swam faster, performed shorter deep dives, and echolocated at a faster rate, with higher frequency clicks. Although they hunt at a similar depth (between 800 and 1300 meters), the Sowerby’s whales clearly employ a different hunting strategy from the other beaked whales.&nbsp;



This first record of a ‘fast’ beaked whale suggests that Mesoplodont whales exploit a broader diversity of deep-sea niches than previously thought. The deep-sea is a rich and diverse hunting ground for marine mammal predators, that have clearly developed a wider range of specialized strategies to be able to exploit it than was previously known.&nbsp;



The marked deviation of Sowerby’s beaked whales from the typically slower behavior of other beaked whales also has potential implications for their response to man-made sounds, which appear to be strongly behaviorally-driven in other species.



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By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Some beaked whales live a "faster" lifestyle than expected

There are 16 species of beaked whales in the genus...

A new study led by the <a href="https://www.exeter.ac.uk/">University of Exeter</a> has found that, although conservation of sea turtles along most of Africa’s east coast has significantly progressed in recent decades, tens of thousands of turtles are still dying each year. This can be largely attributed to human activity, including illegal take and consumption of turtles (especially <a href="https://www.earth.com/news/african-network-helps-protect-green-turtle-populations/">green turtles</a>), bycatch, or loss of nesting and foraging habitats.



“Turtles face many threats along the African east coast, from egg to adult,” said study lead author Casper Van De Geer, a PhD student in Conservation Science at the University of Exeter. 



“Our aim was to bring together everything that is currently known about these turtles, and to identify opportunities to better protect them in this rapidly developing region. We found that there's still a lot we don't know about these turtle populations, like how many there actually are or where they spend most of their time and migrate to.”



By using clutches of eggs laid as a measure of population, Van De Geer and his colleagues have found that some turtle species have recovered quite well in some places, such as the loggerhead turtles in South Africa and Mozambique. Unfortunately, other species, including leatherback and hawksbill turtles, have not responded well to conservation efforts.



While there is good legislation in place to protect turtles, and stakeholder groups are actively participating in conservation activities, greater collaboration with local populations is urgently needed to increase awareness and boost conservation efforts.&nbsp;



“Local knowledge was key to this research, just as it is vital to turtle conservation,” explained Van De Geer. “Conservation work is most effective when it is supported by the local stakeholders and this is achieved through genuine engagement and cultural sensitivity.”



“There are great examples of this along the African east coast where people are trained and employed as rangers or monitors in the area where they grew up, and the use of community theatre or musical performances to inform people about the marine world and conservation. Ultimately, it’s the people who live in a place who have the knowledge and motivation to protect it,” he concluded.



The study is published in the journal <a href="http://dx.doi.org/10.3354/esr01180">Endangered Species Research</a>.



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Thousands of sea turtles still dying on the east African coast

A new study led by the University of Exeter has...

Megalodon, or Otodus megalodon, is a famously gigantic <a href="https://www.earth.com/news/whale-sharks-face-an-uncertain-future-due-to-ship-strikes/">shark</a> that became extinct by the end of the Pliocene around 2.6 million years ago. Common are images of someone holding the jaws of the feared great white shark and being dwarfed within reconstructed O. megalodon jaws.&nbsp;



Now, researchers from <a href="https://www.ncsu.edu/">North Carolina State University</a> and North Carolina Museum of Natural Sciences have found something odd. Megalodon teeth are large enough that one can cover the palm of an adult’s hand. The scientists have found one of these giant teeth oddly deformed and they wondered what caused this.&nbsp;



The tooth appeared split. The paleontologists wondered if genetics, a disease or damage to the tooth bud might have caused the tooth to grow in this strange split fashion and so they decided to investigate.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;



“We don’t have a lot of data on double tooth pathologies in ancient shark species,” said Harrison Miller, a former NC State undergraduate student. “So this was an opportunity to fill in those gaps - and perhaps learn more about the sharks in the process.”



The researchers compared the pathological megalodon tooth with two teeth from a modern bull shark (Carcharhinus leucas) with the same problem. The teeth were CT scanned so that the internal anatomy could be examined.&nbsp;



The experts determined that the teeth were either incompletely split from or joined to each other during development, but no cause could be identified.



“Sharks have cartilaginous skeletons, not boney skeletons, so preservation of their jaws is rare in the fossil record, and usually, we only find the individual isolated teeth. Additionally, sharks have different mechanisms for tooth development – they have continuous tooth replacement, so you can’t look at what is happening in the rest of the jaw to rule out fusion or gemination," explained study co-author Haviv Avrahami.



It is possible that this particular shark took a bite of a stingray or other painfully sharp prey and damaged its tooth.&nbsp;



“With O. megalodon in particular, the current understanding is that they fed mostly on whales,” Avrahami said. “But we know that tooth deformities in modern sharks can be caused by something sharp piercing the conveyor belt of developing teeth inside the mouth. Based on what we see in modern sharks, the injury was most likely caused by chomping down on a spiny fish or taking a nasty stab from a stingray barb.”



There are, in fact, stingrays that lived in the same area at the same time that the scientists think could have caused a shark a bad toothache.



“When we think of predator-prey encounters, we tend to reserve our sympathy for the prey, but the life of a predator, even a gigantic megatooth shark, was no cakewalk either," said Lindsay Zanno, head of paleontology at the N.C. Museum of Natural Sciences.



The study is published in the journal <a href="https://peerj.com/">PeerJ</a>.



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By <a href="mailto:zachfitzner@yahoo.com">Zach Fitzner</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

What caused a giant megalodon tooth to split?

Megalodon, or Otodus megalodon, is a famously gigantic shark that...

Previous research has shown that North Atlantic right whales are declining in size. The whales may be smaller in size due to tangling with <a href="https://www.earth.com/news/dolphin-bycatch-from-fishing-activities-is-unsustainable/">fishing</a> gear and other stresses. Now, new research shows this shrinking could have dire consequences for the endangered whales.



“Smaller females appear to have less capacity to raise calves as frequently as larger whales,” said Joshua Stewart, a research biologist with <a href="https://www.fisheries.noaa.gov/">NOAA Fisheries</a>’ Southwest Fisheries Science Center. “Their smaller size means they may take longer to recover from the energetic cost of giving birth, especially in light of other stresses on the population.”



Stewart collaborated with other researchers from Oregon State University, Woods Hole Oceanographic Institution, the New England Aquarium, and SR3 on the findings. The scientists were able to examine the whales using high quality aerial photography.&nbsp;



“We were able to measure whales by flying a camera high above them, essentially giving them a health check without them knowing we were there,” said study co-author John Durban.



The research showed that larger females were able to give birth to larger and healthier offspring. Over the course of years, larger whales also produced more young. The birth rate of the 350 remaining right whales is currently at a 40 year low. This is partially due to entanglement in fishing gear the research suggests.&nbsp;&nbsp;



“After decades of research on this species, we have learned about the stressors right whales face and, with this study, have gained further insights into how these stressors are affecting their reproduction,” said study co-author Amy Knowlton.&nbsp;



“The remedies to address these threats are clear: shifting how humans operate in the ocean so that do not inadvertently harm whales. That means adapting to weaker ropes used for fishing and ultimately ropeless fishing gear as well as broader areas of vessel speed restrictions in the right whale’s range. With these changes, we could reverse the decline we are witnessing in this species.”&nbsp;



Other factors likely also play a role in the fecundity of the whales, including lack of prey, driven by human causes. Hopefully this research helps secure a future for these beautiful creatures.&nbsp;&nbsp;



The study is published in the journal <a href="https://www.int-res.com/journals/meps/">Marine Ecology Progress Series</a>.



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By <a href="mailto:zachfitzner@yahoo.com">Zach Fitzner</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Dwindling right whale population linked to shrinking bodies

Previous research has shown that North Atlantic right whales are...

On a mild summer evening, grasshoppers and <a href="https://www.earth.com/news/mating-crickets-lower-their-standards-when-exposed-to-traffic-noise/">crickets</a> share an impressive concert to anyone walking by with their chirping. The sounds are usually males trying to attract females to mate with them. But some can be the sound of a rivalry when two males get too close to each other.



In Germany, there are more than 80 Orthoptera species. The feeding habits of grasshoppers are a scientifically exciting topic. Most recently, scientists have been looking to understand how food webs can remain stable under a changing climate.&nbsp;



A recent study published in the journal <a href="https://onlinelibrary.wiley.com/journal/13652486">Global Change Biology</a> has investigated how grasshoppers interact with plants. The researchers investigated orthoptera-plant communities in different regions to complete an analysis along a climatic gradient, at altitudes ranging from 250 to 2,100 meters.



"Grasshoppers are very important for many open grassland ecosystems," said zoologist Sebastian König from the <a href="https://www.uni-wuerzburg.de/en/university/">University of Würzburg</a> in Bavaria, Germany. "The insects are an important food source for birds. And as herbivores, they remove up to 30 percent of the plant biomass in a meadow, thus promoting the co-occurrence of many plant species."



During the summers of 2019, 2020 and 2021, the team determined which grasshopper species fed on which plants on 41 grassland sites. They observed more than 3,000 individuals of 54 species and collected the fecal pellets of the animals to analyze the plant remains they contained.



The ecologists tested a hypothesis that it should be advantageous for insects at higher altitudes to feed on a broader range of plant species, because in high alpine environments, the choice of food plants is limited. Therefore, and because of environmental variability, it is advisable not to be too choosy there.



The study partially confirms the theory, as grasshoppers were found to eat a relatively wide range of plants in cold regions. The experts also found that this applies to warm habitats.&nbsp;



However, in temperate habitats the number of plant species is large and grasshoppers are more specialized, feeding on plants that are closely related. Resource composition also plays an important role for the herbivores. For example, grasshoppers with a preference for grasses dominate in meadows with a high proportion of grasses.



"Our results suggest that climate and plant community composition influence the dietary specialization of herbivores. If herbivores devour many different species, this could be an adaptation and a prerequisite for being able to survive in climatically extreme habitats," the researchers concluded.&nbsp;



The scientists now want to gather information about the food niche breadth of herbivorous insects. Next, they will analyze the microorganisms that live in the guts of the grasshoppers. This could reveal potential relationships between the diet and the diversity and composition of the microorganisms.



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By <a href="mailto:katherinebucko@gmail.com">Katherine Bucko</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

New clues about the feeding habits of grasshoppers

On a mild summer evening, grasshoppers and crickets share an...

Dragonflies, one of the most ancient <a href="https://www.earth.com/news/scientists-have-found-a-terrifying-decline-in-flying-insects/">insect</a> species, are highly skilled flyers, exhibiting a repertoire of complicated flight maneuvers. For instance, they have evolved sophisticated reflexes that enable them to right themselves when falling or after being flipped upside-down during flight. 



According to a new study led by <a href="https://www.cornell.edu/">Cornell University</a>, dragonflies’ nimble righting reflexes are complex processes involving signals from their visual system and dynamic muscular control of wing pitch. 



“Insects have evolved sophisticated reflexes to right themselves in mid-air. Their recovery mechanisms involve complex interactions among the physical senses, muscles, body, and wings, and they must obey the laws of flight. We sought to understand the key mechanisms involved in dragonfly righting reflexes and to develop physics-based models for understanding the control strategies of flight maneuvers,” explained the study authors.



By using a series of kinematic analyses, physical modeling, and three-dimensional flight simulations, the scientists discovered that dragonflies use wing pitch asymmetry between the left and the right wings to drive upright recovery in less than 200 milliseconds. 



In a second step, the experts aimed to determine through behavioral experiments whether these wing movements are elicited by upstream sensory signals. They blocked the insects’ visual systems while observing their ability to perform the complex movements required to flip over. This revealed that the loss of visual sensory information impaired the dragonflies’ ability to perform mid-air righting, implying a clear connection between visual signals and the insects’ motor reflexes. 



“These results suggest a pathway from the dragonfly’s visual system to the muscles regulating wing pitch that underly the recovery,” said the study authors.



“The methods developed here offer quantitative tools for inferring insects’ internal actions from their acrobatics, and are applicable to a broad class of natural and robotic flying systems,” they concluded.



The study is published in the journal <a href="http://dx.doi.org/10.1126/science.abg0946">Science</a>.



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

How do dragonflies right themselves in mid-air?

Dragonflies, one of the most ancient insect species, are highly...

Sthenolepis areolata

Taxonomic tree: