Discover Top Posts Tagged with #pelagic fish

Kradimus

Kradimus! very weird fish from Morocco, we still have no clue what it used those disproportionately long pectoral fins for done while in call with @/EnnieNovachrono (on twitter)!!!

#paleoart #digital art #paleontology #digital artwork #artists on tumblr #palaeoart #digital illustration #sciart #id in alt text #paleoblr #palaeoblr #fish #fish art #extinct fish art #pelagic fish

The Can-do Pelican Eel

The pelican eel, also known as the gulper eel (Eurypharynx pelecanoides), are the only known species of eel in the family Eurypharyngidae. They are found exclusively in the deeper parts of the water column, from depths of 500 up to to 3,000 m (1,600 to 9,800 ft), but are distributed throughout all the world's oceans.

The gulper eel is perhaps most famous for its unique body shape. Like many deep-sea fish, this species is highly adapted to its environment; maximum energy efficiency is the highest priority. To that end, the pelican eel has a large head, and a jaw estimated to be quarter of the total length of its body. The jaw is loosely hinged, meaning that gulper eels can open their mouths extremely wide. The rest of the eel, in contrast, is quite slender and long, about 0.75 m (2.5 ft) in length on average. Most individuals are black--so black, in fact, that they only reflect 0.5% of light; perfect for hiding from potential predators.

Although they look skinny, E. pelecanoides can expand their stomachs to hold prey much larger than themselves. Their primary prey consists of crustaceans and cephalopods, though they may feed opportunistically on other fish. Because it is so well camouflaged, it uses bioluminescent organs on the tip of its tail to attract prey. Gulper eels themselves are preyed upon by lancetfish and other larger deep-sea fish. To deter predators, they will gulp down a large amount of water; this stretches the loose skin around their head and throat, and inflates them to several times their usual size.

Because of their remote location, the breeding habits of gulper eels are relatively unknown. However, it is believed that smell plays a large part in attracting a mate, as pelican eels have highly developed olfactory organs. Like other eels, they're born as tiny, transparent larvae in a state known as the leptocephalus stage. At this stage, they do not have any red blood cells. Researchers aren't sure how long it takes gulper eels to become fully mature, or how long they live, but many believe that adults die shortly after mating.

Conservation status: The population size of E. pelecanoides has not been assessed, and thus the IUCN has not made a determination on its status. The greatest threat for this species is deep-sea trawling, which frequently brings up gulper eels as by-catch.

Photos/Video

Paul Caiger

Schmidt Ocean Institute

EV Nautilus Team (I highly recommend checking out their 2023 highlights reel!)

The creature of the moment: The basking shark

(Cetorhinus maximus)

Aka my favorite animal

Basking sharks, a slow moving migratory shark, are the ocean's 2nd largest fish growing to be as long as 40ft.

Their common name "basking" shark comes from their habit to swim close to the surface, aka seeming to be "basking" in the sun

They travel in pairs or in large groups of up to 100+.

They are not a well researched species due to their low numbers, and their size does prove it impossible to study them in a lab setting. What is known is that they may be long lived (reaching 50 years of age), live in arctic and temperate waters, and that they are under the order lanniformes.

The lamniforme order contains many of the most well known sharks, (like great whites, threshers, basking sharks, makos, etc), and has an interesting ability to retain metabolic heat, a trait that other orders of sharks do not obtain and makes them functionally warm blooded.

Though little is known about their life history, it is theorized that they may be ovoviviparous as that is a lamniforme trait as well. It is also believed that they have a lengthy maturation time and a gestation of possibly 3 years.

The basking shark feeds by filtering feeding through gill rakers, filtering out 2,000 tons of water within their gills per hour.

Another unknown about basking sharks is their breaching behavior. They have been shown breaching out of the water, which takes many by surprise by the power needed for such a large animal to do. The reason has a few theories, however none have been completely proven. These include being a mating ritual for males to jump and essentially show off to prospective mates. Another is to kill parasites by crushing them by the force.

Historically, they were hunted nearly to extinction in the 1800's. Most fish have a gas bladder to control their buoyancy, but sharks have an oily and nutrient rich liver that keeps them buoyant instead. The basking shark was hunted for this liver to use as oil to keep lights running. Other reasons were to use the skin as sand paper due to their rough skin, fins for food and in some countries as an aphrodisiacs, and to protect the fishers' nets as they get tangled in.

Luckily, conservation efforts have been underway to protect them and they are now under "vulnerable" on IUCN's red list.

They have also fooled people plenty of times into thinking that they were sea serpents (in this case sharks cruising in single file), and most notably mistaken for pleisiosaur carcasses. The latter being due to the way they decompose - the skull is small compared to the body length of the shark- making people not even think it was a shark.

Overall, basking sharks are a peaceful species, large, and sometimes looks rather derpy. It's why they're my favorite, along with the mysteries still surrounding their behavior and biology.

sources:

#sharks #basking shark #pelagic fish #lamniformes #it would be something like creature of the week or month or w/e #but its 100% based on when i feel like making these things #not a fixed schedule on them #creature of the moment #my research posts

The Chinese fishing industry already has a presence in Madagascar - six Chinese vessels have been trawling for demersal (deep-water) and pelagic (neither deep-water nor near-shore) fish off southwest Madagascar since October 2017, according to the Fisheries Ministry. Small-scale fishermen in the area say they feel the impact of the trawling on their catches, even from this relatively small fleet. Officially, these six are the only Chinese vessels working Madagascar’s waters, but the real number is believed to be much higher. Reports in the news and from local observers indicate that a large number of Chinese ships are working there illegally, sometimes using highly destructive fishing methods and strong-arm tactics to muscle local fishers off the water. But Madagascar’s small-scale fishermen also face competition beyond the Chinese, for example from domestic and foreign industrial shrimp trawling and long-line tuna fishing by vessels from South Korea, Seychelles and Europe.

Edward Carver, 'Fishermen oppose $2.7 bn deal opening Madagascar to Chinese fishing', Asia Times

#Asia Times #Edward Carver #Chinese fishing industry #Madagascar #Chinese vessels #trawling #demersal fish #pelagic fish #southwest Madagascar #Fisheries Ministry #Small-scale fishermen #Chinese ships #destructive fishing methods #strong-arm tactics #industrial shrimp trawling #long-line tuna fishing #South Korea #Seychelles #Europe

A Striking Salmon Shark

A close cousin to great white sharks and a formidable apex predator, the salmon shark (Lamna ditropis) is common sight in the frigid northern Pacific ocean. It spends most of its time in the open ocean, but it can be spotted off both Asian and North American coasts from the Arctic Circle to as far south as the Sea of Japan. However, it is most frequently seen near the Prince William Sound in the American state of Alaska in the summer, due to the area’s annual salmon run.

As expected from the name, the principle food of the salmon shark is salmon. This is especially true in the summer, when salmon return to their breeding grounds. The influx of prey into bays, coves, and river outlets makes it easy for sharks to gorge themselves on the excess population. Over the rest of the year, the salmon shark’s diet broadens to include herring, mackerel, birds, small to medium aquatic mammals, and squid. Despite being an apex predator, the salmon shark does have some predators of its own, mainly great white sharks and blue sharks; however, these mostly only prey on juvenile salmon sharks.

Like many other shark species, salmon sharks are largely solitary. One unique feature of this species is that the sexes are divided; eastern populations are largely female, while western populations are mainly male. Reproduction occurs in the late summer or early autumn, which coincides with the annual salmon run on the eastern Pacific coast. L. ditropis is ovovivparous, meaning its eggs develop inside the mother and young are born live in litters of two to six pups. Gestation takes about nine months and females only mate once every two years. Individuals can become sexually mature at anywhere from five to nine years old, and in total they can live up to 25 years.

Although they are closely to and resemble great white sharks in many aspects, there are some key differences between great whites and salmon sharks. For one, L. ditropis is much smaller; only 2-2.6m long and 220kg. Males tend to be slightly smaller than females. Salmon sharks are also slightly darker than great whites, with dark grey or black backs and a white underbelly. Another distinguishing feature for salmon sharks is their ability to thermoregulate. Most fishes cannot maintain an internal temperature, which is why it’s so important that they stay in water within their tolerance range. Salmon sharks are endothermic, meaning they maintain a constant internal temperature. They also have the highest internal body temperature of any shark species at about 18-27° C. In order to maintain this temperature in the cold north Pacific, L. ditropis has arteries and veins that are very close together to exchange heat, cold water from the gills cools blood close to the skin so that little to no heat is lost.

Conservation status: The IUCN lists the salmon shark as Least Concern. The population is currently stable, although it faces threats from fishing as both a source of meat and by catch, as well as loss of food from overfishing of the salmon it relies on in the summer.

Photos

Ron Watkins

Washington Department of Fish and Wildlife

Alaska Department of Fish and Game

#salmon shark #Lamniformes #Lamnidae #mackerel sharks #white sharks #sharks #cartilaginous fish #fish #open ocean #open ocean fish #pelagic fauna #pelagic fish #coasts #Coastal Birds #pacific ocean #arctic circle #animal facts #biology #zoology

The Handsome Hagfish

Requested by @anxiouspuddle

Hagfish, of the family Myxini, are a group of 75 jawless fish species that reside in the Pacific, Atlantic, and Indian Oceans. Although they are vertebrates, they are the only known animals that have a vertebral column but no skull. Many scientists consider them to be an evolutionary descendant of the ‘stepping stone’ between fish with and without jaws. Their evolution and juvenile development has been the subject of much study, trying to determine the pathway of the evolution of jaws, skulls, and eyes in vertebrates.

Although they are sometimes mistaken for eels, hagfish have many easy-to-distinguish physical differences. For one, hagfish have a skeleton made of cartilage while eels have a harder bone skeleton. Secondly, Myxini species have open holes for gills rather than the slits more characteristic of eels and fish, and can also breathe through their skin if needed. Lastly, hagfish have no eyes or identifiable jaws; rather, their mouths are made of several protruding barbs and a set of horizontal cartilaginous structures that can expand outward. The main resemblance to eels is the body structure: hagfish have long flexible bodies and a paddle-like tail suited for smooth swimming. Hagfish species can be anywhere from 18 to 127 cm long, although the average length is around 50 cm, and their colors can range from pink to dark blue to brown.

Like eels, little is known about hagfish reproduction. The mating process in particular is a mystery, although females will lay eggs year round. Eggs are laid in batches of 30-40, and can take up to 11 months to hatch-- longer than many other jawless vertebrates. Freshly hatched hagfish are precocial, meaning they require no parental care or supervision. It is not known how long Myxini species age before they are sexually mature; however, it’s generally believed that they grow reproductive organs at around 35 cm. Evidence indicates that they are a hermaphroditic group. This means that at some point in their lives, hagfish change their sex from male to female or vice versa.

Outside of mating, hagfish are solitary. They are benthic animals, spending most of their time at the bottom of the ocean. They feed mainly on polychete marine worms, although carcasses like whales are famous for drawing massive aggregations of hagfish. When presented with large meals, hagfish will burrow inside the body and consume it from the inside out. However, they only exhibit this behavior on dead or dying animals, and generally only prey on living creatures smaller than themselves. Myxini species can survive for months between feedings, as do many benthic animals. Similarly, hagfish are nocturnal and hide in burrows of mud on the ocean floor.

Hagfish are preyed upon by many different animals, including sharks and harbor seals. To evade predation, they can twist themselves into complex knots or-- perhaps most famously-- produce large amounts of slime. This slime, or mucus, is produced from glands along the hagfish’s body. It’s protein-based and made of thick filaments that, when combined with salt water, expand into a thick membrane that doesn’t dissolve or dry out. The amount of slime produced seems only dependent on how much water is available and how long the hagfish perceives a threat. If ingested, the slime can choke a potential predator or clog its gills, giving the hagfish ample time to escape.

Conservation status: Hagfish are fairly common throughout the ocean, although some species are threatened. Although they are part of human diets in some countires, the main threat comes from the lack of food available; as larger marine fauna like whales and sharks disappear, the amount of carcasses for Hagfish to feed on also diminishes.

Photos

Andy Murch

Joel Sartore

#hagfish #Myxiniformes #Myxinidae #fishes #jawless fish #fish #marine fauna #marine fish #benthic fauna #benthic fish #deep sea fauna #deep sea fish #pelagic fauna #pelagic fish #open ocean #open ocean fish #Pacific Ocean #atlantic ocean #indian ocean

The Astounding Northern Anchovy

Famously, or perhaps infamously, known for their place in the culinary world, Northern Anchovies or California Anchovies (Engraulis mordax) is a species of pelagic forage fish native to the Pacific ocean. Like all anchovies, they are silver with bluish-green coloring on the back and sides. They generally weigh up to 10 g, and can be as long as 9 cm. The best way to distinguish E. mordax from other anchovy species is their anal fin; unlike other anchovies, the Northern Anchovy’s bottom fin begins parallel to the end of the top fin.

The California Anchovy’s range spans from British Columbia in Canada to Cabo San Lucas, Mexico. Their ideal habitat is in open oceans near coastal upwellings, with a maximum depth of 200 m and a temperature range of 8 to 25 C. Generally they’re found between 30-400 km offshore, but they are known to enter bays and inlets in search of food. Two main sub-populations exist; one off the coast of the Pacific Northwestern United States and another near Baja California, Mexico. The northern population is more migratory, travelling to deeper waters in the winter.

Northern Anchovies have a relatively short lifespan; only about 4 or 5 years without predation. In that time, however, they can produce hundreds of offspring. They become sexually mature at around 2 years old, at which time females begin spawning eggs. About once a week they release batches of over 500 eggs, which are then fertilized with sperm released by the males. Fertilized eggs can hatch only 4 days later, and larvae develop quickly. E. mordax breeds throughout the year, but reproduction peaks in spring. This is an especially bountiful time for the California Anchovy’s predators, as planktivores, fish, seabirds, and marine mammals will gather to feed on the transparent larvae and their swarming parents.

When predated upon, Northern Anchovies perform a unique defense mechanism called schooling. Their bluish-green and silver coloring provides a sort of camouflage against the open ocean and makes it difficult for predators to distinguish individuals for targeting. The school moves together as one tightly balled unit, and stragglers who cannot keep up with the group are quickly singled out and eaten.

Despite their reputation as prey, northern anchovies are themselves predators of tiny invertebrates like copepods and decapod larvae. They can filter-feed and actively pursue prey. When hunting, an individual forms an S-shaped posture, using its coloring as camouflage, and undulates its dorsal fins to propel itself. Generally, anchovy larvae are more active hunters than adults.

Conservation status: Rated as Least Concern by the IUCN. The Northern Anchovy has been fished extensively as a source of food and fishing bait for human use. While the current population is thought to be stable, catch rates have been steadily decreasing since 1983.

#northern anchovy #Clupeiformes #Engraulidae #anchovies #Bony fish #Ray-Finned Fish #fish #open ocean #open ocean fish #pelagic fauna #pelagic fish #Pacific Ocean #marine fauna #marine fish

Discover the Best Seafood Export Company in Canada for Pelagic Fish

Seafood is an essential part of a healthy and delicious diet, offering a wealth of protein, vitamins, and minerals. Pelagic fish, in particular, are prized for their high omega-3 content, which has been shown to reduce the risk of heart disease, stroke, and other health issues. This category of fish, which live and feed in open waters away from the ocean floor,