Tag Archives: Crustacean

Newly found predatory crustacean within the depths of the Atacama Trench

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of atacama trench It stretches along the eastern South Pacific, dropping to depths of more than 8,000 meters off the coast of northern Chile.

dursibela kamanchakaholotype female. Image credit: Weston others., doi: 10.1080/14772000.2024.2416430.

The deepest 45% of the ocean (6,000-11,000 m), the Hadar Zone, contains high levels of undiscovered biodiversity.

Most geological formations are characterized by grooves formed in subduction zones between tectonic plates, which are formed by a series of unique external and internal factors.

The Atacama Trench, or Peru-Chile Trench, is one of the most geographically isolated landforms, located beneath eutrophic surface waters and characterized by high sediment loads.

This trench is known to host highly distinctive faunal assemblages driven by a combination of these isolating factors.

“The deep sea is a vast trove of new species for science, and each discovery deepens our ecological understanding of these remote ecosystems,” said researcher Johanna Weston of Woods Hole Oceanographic Institution and colleagues.

“One such island-like ecosystem is the Atacama Trench, where unique endemic communities exist at hadal depths (more than 6,000 meters).”

“Unlike other Hadal subduction ditch communities, it is a predatory (non-predatory) amphipod It has not been documented or collected from the Atacama Trench. ”

The newly discovered species dursibela kamanchakathe first large active predatory amphipod discovered at these extreme depths.

This crustacean, about 4 cm long, uses specialized raptor appendages to capture and prey on small amphipods in food-limited areas of the Atacama Trench.

“Most interestingly, the DNA and morphological data indicate that this species is also a new genus, highlighting the Atacama Trench as a unique hotspot,” Dr. Weston said. .

The discovery was made during the 2023 Integrated Deep Ocean Observing System (IDOOS) expedition. R/V Abate Molina.

4 dursibela kamanchaka Individuals were collected using a lander at a depth of 7,902 m. Landers are untethered platforms used to shuttle scientific equipment, such as baited traps, to the ocean floor and back.

“The collaborative and integrative approach of this research is confirmed.” dursibela kamanchaka This is a new species discovered and highlights the ongoing discovery of biodiversity in the Atacama Trench,” said Dr. Carolina González, a researcher at the Instituto Milenio de Oceanografía.

“This discovery highlights the importance of continued deep-sea exploration, especially in the Chilean forecourt.”

“We expect more discoveries as we continue to study the Atacama Trench.”

This finding is reported in the following article: paper in a diary Systematics and biodiversity.

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Joanna New Jersey Weston others. 2024. A new large predator (family Lycoptidae, Eucilidae) hiding in the depths of the Atacama Trench. Systematics and biodiversity 22 (1): 2416430;doi: 10.1080/14772000.2024.2416430

Source: www.sci.news

Pharmacological potential discovered in toxins found in crustacean venom from Mayan underwater caves

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Xibalbanus turmensisThe poisonous remipede, found in the caves of Antiarin on the Yucatan Peninsula, is the only crustacean for which a venom system has been described.

Xibalbanus turmensis. Image credit: Pinheiro-Junior others., doi: 10.1186/s12915-024-01955-5.

“Poisonous animals inject toxic compounds into other organisms primarily for self-defense or predation,” said Dr. Björn von Roymont, a researcher at Goethe University Frankfurt, and his colleagues.

“Many venoms are composed of proteins that have evolved to modulate various physiological functions in the target organism.”

“Studying these biological activities could lead to pharmacological or agrochemical applications.”

“The majority of thoroughly studied venoms and venomous proteins originate from iconic terrestrial groups, primarily snakes, spiders, scorpions, and insects,” the researchers said.

“Research attention to marine life has been limited, with only a few fish and invertebrates being better studied, such as sea anemones, jellyfish, cone snails, cephalopods, polychaetes, and more recently nemertes.”

“Venoms and their toxic proteins have evolved independently in different animal lineages, so the study of new lineages provides an opportunity to identify novel toxic compounds with interesting biological activities, on the one hand, and generally convergent proteins on the other hand. It provides an opportunity to improve our understanding of the evolution of functional traits.”

In their study, the researchers investigated the biological activity of peptides found in crustacean venom. Xibalbanus turmensis.

This underwater cave-dwelling crustacean belongs to the following classes: Remipediafirst described in the 1980s and currently consists of 28 extant species.

“Xibalbanus turmensis They live in cenotes, underwater caves in Mexico's Yucatan Peninsula,” the scientists said.

“Cave dwellers directly inject the venom produced by their venom glands into their prey.”

“This toxin contains a variety of components, including a new type of peptide named cibalbin after the crustacean producer.”

“Some of these sibalbins contain characteristic structural elements that are well known to other toxins, especially those produced by spiders. Some amino acids (cysteine) in the peptide are tied together like a knot. are connected to each other in such a way that they form a structure.

“This makes the peptide more resistant to enzymes, heat, and extreme pH values.”

“Such knots often act as neurotoxins, interacting with ion channels to paralyze prey. This effect has also been proposed for some cibalbins.”

This study shows that all sibalbin peptides tested by the team, particularly Xib1, Xib2, and Xib13, effectively inhibit potassium channels in mammalian systems.

“This inhibition is very important when developing drugs to treat a variety of neurological diseases, including epilepsy,” Dr. von Roymont said.

“Xib1 and Xib13 also exhibit the ability to inhibit voltage-gated sodium channels, such as those found in neurons and cardiomyocytes.”

“Furthermore, in higher mammalian sensory neurons, the two peptides can activate two proteins involved in signal transduction: the kinases PKA-II and ERK1/2.”

“The latter suggests that they are involved in pain sensitization, opening the door to new approaches in pain treatment.”

of the team findings Published in a magazine BMC biology.

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EL Pinheiro – Junior others. 2024. Xibalbin mutants divergently evolved from remipede toxin inhibit potassium channels and activate PKA-II and Erk1/2 signaling. BMC biol 22, 164; doi: 10.1186/s12915-024-01955-5

Source: www.sci.news

400 Million Years Ago, A Giant Scorpion Might Have Been a Crustacean

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Extinct giant aquatic arthropods called sea scorpions (Eurypterids) were apex predators. A new study suggests that early species of carcinosomatoids, with their scorpion-like spiny limbs, fed on trilobites, while later species preferred armored fish. Carcinosomatoids evolved into scorpions, but not the giant scorpion-like creatures that lived 400 million years ago. Preactorus and Brontoscorpio which is published in Walking with monsters (TV series) was probably a crustacean.

Reconstruction Pentecopterus (170 cm long), the oldest known sea scorpion (Eurypteridae), from the Ordovician Period (467 million years ago) of Iowa, USA. Image by John Alexander.

Sea scorpions (family: Ophiocephalidae) are ancient aquatic creepies (arthropods, meaning they have segmented bodies, exoskeletons, and jointed legs) that lived from 467 million years ago until about 253 million years ago.

Some pterygian Eurypterids can grow to lengths of nearly 2.6 metres, making them the largest insects ever to have lived. Eurypterids also include the predatory carcinosomatoids, namely the megalograpts, carcinosomatoids and mixopterids, which have long spiny limbs and can grow to lengths of up to 2 metres.

Carcinosomatoids used their long, spiny limbs to catch prey and burrow into the mud, and computer models suggest that they were slow swimmers who preferred to live close to the sea floor as ambush predators.

New research on fossils found alongside megalograptids suggests that they were primarily associated with trilobites, a diverse group of extinct marine arthropods.

Carcinosomatids tend to live in symbiosis with lightly armoured phyllocallid crustaceans and lingulid brachiopods (lamp shells).

Mixopterid fishes tend to coexist with more heavily armoured fishes such as therodonts, osteostracans and pteraspids.

Fossilized feces (coprolites) prove that they ate trilobites, armored fish, and even their own kind (cannibals).

The idea that nudibranchs influenced the evolution of armored fishes in the predator-prey arms race is often dismissed.

The study suggests that mixopterids and pterygians had some influence on their evolution (and on our very ancient ancestors).

Megalograptus is interpreted as being more primitive than previously thought, which means that early (Ordovician) crinoid diversity has been overestimated.

Scorpions are thought to have evolved from a Mixopteridae-like ancestor, evolving claws (palps), stingers, and comb-like sensory pecten on their undersides.

Giant scorpions may be the creatures of your nightmares, but they actually existed in Scotland's Carboniferous period. Pulmonoscorpiusand Gigantoscorpio.

Reconstruction PulmonoscorpiusA giant scorpion (70 cm long) from the Carboniferous period of Scotland (330 million years ago). Image by Junnn11 / CC BY-SA 4.0.

Even longer (1 meter) scorpions PreactorusThis dinosaur, which lived in Herefordshire, England, is also thought to have lived 412 million years ago.

However, the grooves on its shell, the pustular ornamentation, and the recurved first segment suggest that it is in fact a crustacean.

Bennett TaltraThey come from the same layer and region and may be related (or slightly smaller) Preactorus.

BrontoscorpioIt is an estimated 86cm long (400 million years old) scorpion featured in a BBC television series. Walking with monstersOnly a small portion of the claws are known, and it is probably a crustacean. Image courtesy of Impossible Pictures.

Brontoscorpio(86cm long), discovered in Worcestershire, England (400 million years ago) and featured in an award-winning BBC television series. Walking with monsters Possibly a crustacean too.

So giant scorpions, along with giant millipedes measuring two metres in length and giant dragonflies with wingspans of 75 centimetres, didn't come into existence until the Carboniferous period 70 million years later.

Modern scorpions gradually acquired their modern characteristics: early scorpions had more primitive legs and eyes, and lacked an anterior mouth cavity for feeding on land, so were probably aquatic or amphibious.

The oldest known scorpion Palioscorpio It was discovered in Wisconsin from the Early Silurian (437 million years ago) but has been reinterpreted as a trilobite-like arthropod.

The oldest scorpion is now Dolichophonus (433-438 Ma) Originating from Scotland.

this the study Published in New Jarlbuch in Geology and Palaeontology.

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Braddy, S.J. 2024. Palaeoecology and phylogeny of carcinosomatid eurypterids: ichnolog- y and palaeoassemblages. New Jarlbuch in Geology and Palaeontology; doi: 10.1127/njgpa/2024/1206

Source: www.sci.news