#bonnethead shark

[uncharismatic-fauna]

Uncharismatic Fact of the Day

Can you guess where the shovelhead shark got its name? It's because its head-- wait for it-- looks like a shovel! This is particularly true of males, which have a distinctive bulge in the center of their foreheads, creating the very distinct impression of a spade, while females have a much flatter head. This distinguishing feature also gives the bonnethead shark the unique position of being the only shark species that exhibits sexual dimorphism through the shape of the head.

(Image: A male bonnethead shark (Sphyrna tiburo) by Gerard Soury

[feelingautistic]

Contrary to popular belief, not all sharks are carnivorous. The bonnethead shark (a member of the hammerhead sharks) was recently discovered to be omnivorous, including seagrass in their diet.

[makabrefantasies]

Finished cardboard bonnethead shark

[protectoursharks]

do you know any really cool things about hammerhead or bonnet head sharks? they’re some of my favorites. thanks!

Bonnethead Shark or Sphyrna tiburo

My favorite fact about these sharks is that THEY'RE OMNIVORES! This is the first shark that is an active hunter that has been found to consume plants! (Filter feeders like whale sharks also eat plant matter because filter feeding isn't a selective process) Up to 60% of this shark's diet is sea grass!

There are about 10 recognized species of hammerhead sharks (Sphyrnidae family) and the bonnethead shark is the smallest, they grow up to 1.2 m (4 ft). They're also known as shovelhead sharks because of their unique head shape!

[respect-the-locals]

Found on Pinterest 😍😍 had to share!!

🎨: The Art of Ama @nekoama

[unofficial-sean]

Eyeauh

[sharkest-sharks]

I have to know:

If you could would you ever keep a shark as a pet (if it was 100% healthy for the shark and like ethical and shit) and if so is there a specific kind of shark?

off the top of my head i'll say bonnethead shark, they just look so extremely silly

[fishenjoyer1]

Fish of the Day

Today's fish of the day is the bonnethead shark!

The bonnethead shark, also called bonnet shark, or shovelhead, scientific name Sphyrna tiburo, is known for its unique head shape. It is often thought that the bonnethead shark is a young hammerhead shark, and despite belonging to the same family, Sphyrnidae, they are not the same species. Unlike the hammerheads worldwide range, the bonnethead shark's natural range only stretches from Southern Canada down to The coast of Brazil and Peru, with populations on both coasts of the Americas. It lives primarily in estuaries or bays, living around vegetation, sandy bottomed areas, or reefs. These are a migratory species: during the summer they move inshore and further North, but during Winter they move back south. Eastern populations concentrate around the Carolinas in Summer, and the Florida coast or Caribbean sea during the other months, but there are no concentrated points known for Pacific populations.

Bonnethead sharks, similar to other sharks of their size, eat primarily crustaceans. Crabs, shrimp, mollusks, and small fish.  Similar to hammerhead sharks, they have many electromagnetic sensors on the underside of the head, this is the reason for the spade shape as the spacing of the sensors allows them to better find prey below them. They hunt along the sea bed, moving the head similar to how one moves a metal detector, looking for electromagnetic irregularities produced by living beings. After detection, the shark turns sharply and bites into the sediment, then grinding prey and swallowing. When unable to find prey, or in larger groups they also have been found eating seagrass. Other than for detection of prey, this head can also be used for better vision: as the eyes are faced to the sides this gives them a much wider field of view, allowing them to see if any predators are around, something that gives them a higher chance of surviving past childhood.

The reproduction of the bonnethead shark is viviparous, meaning that the baby is formed inside the mother and born alive. breeding is thought to take place around spring and autumn in the Atlantic populations, but may take place year round without a proper season for it. However, these fish will breed only after they've reached 31 inches in females, and 24 inches in males at around their second year of life. Then, after breeding, gestation takes only 5 months before they have anywhere between 4-12 pups, who are already 12 inches in length. These pups are then abandoned, primarily to keep the parents from feeding on their own offspring, and will live in and around seagrass beds they were born in. This is where they can hide from predators for the first few years. The largest bonnethead shark reported was 4 feet in length, but most are only 2.5-3 feet long. Male and female bonnetheads can be told apart by the sexual dimorphic morophology of the head shape. In females, the head is rounded, but males have a bulge shape around the midline of the head, referred to as a cephalofoil.

Their behavior is unlike many sharks, as bonnetheads are known to exist in groups. Living in smaller numbers of 5-15 in a pod, although there have been schools of thousands reported to be traveling with one another. These groups are not territorial, but they have a hierarchy within them. Strangest of all, these sharks appear to communicate with one another using cerebrospinal fluid as a chemical communicator between individual sharks, letting the others know where they are at any given time.

That's the bonnethead shark, everybody! Have a wonderful day.

[chronicallyleggless]

Shark userboxes! (Full pack)

Sorry if I used a wrong image for one of the sharks!

[fishyfishyfishtimes]

Daily fish fact #797

Bonnethead shark!

Their shovel-shaped cephalofoil (or hammer) is a distinguishing feature among hammerhead sharks, and sharks overall. They use cerebrospinal fluid in chemical communication, letting other bonnetheads know they are in the area!

[quark-nova]

Since y'all liked my previous shark post, here's the only plant-eating shark!

Bonnethead shark!

[marinelifecatalogue]

BABE WAKE UP NEW SHARKS JUST DROPPED!!!

A new species of Chimaera/Ghost shark was recently discovered in the deep waters of New Zealand. It's been dubbed the 'Narrow-Nosed Spookfish', and given the scientific name Harriotta avia in reference to the discoverer's grandmother. This new species was found just in time for spooky month to begin!

There's also a new species of hammerhead shark called the Shovebill Shark, or Sphyrna Alleni. Originally, it was considered a subspecies of bonnethead shark. Upon further inspection, the Shovebill Shark actually has a different head shape, number of vertebrae, and DNA profile!

[feelingautistic]

A new species of hammerhead shark related to the bonnethead shark has been discovered!

Sphyrna alleni (also known by its common name 'shovelbill shark') has been confirmed to live in the Caribbean and Southwestern Atlantic.

(The image above is taken from the published paper on this discovery: Gonzales, C. et al. (2024), 'Sphyrna alleni sp. nov., a new hammerhead shark (Carcharhiniformes, Sphyrnidae) from the Caribbean and the Southwest Atlantic.' Zootaxa, 5512(4), 491-511. DOI: 10.11646/zootaxa.5512.4.2)

[bethanythebogwitch]

It's Wet Beast Wednesday and this week's topic is Sphyrna tiburo, the bonnethead shark. This is a small and wildly adorable species of hammerhead shark that has some very unique features not found in other sharks.

As with most sharks, females are larger than males, reaching an average of about 0.7 to 1 meter (2.3 - 3.3 feet) in length with the longest recorded specimen being 1.5 meters (5 feet). They live in shallow waters, preferring to live in seagrass beds and muddy or sandy sediment. They are found on both coasts of the Americas in warm seas, though they can be found as far north as New England or northern California in rare cases. They migrate south during the winter. Bonnetheads are social and usually live in groups of 5 - 15 members, but can occasionally school in the hundreds or thousands, usually during migration. Scientists have identified at least 18 social behaviors, often used to display dominance or compete for mates. Bonnetheads are very timid and flee from humans. Only one attack on a human has been recorded and it left minor injuries.

One of the unique features of the bonnethead is the fact that they are the only shark species to have sexual dimorphism of the head. Sexual dimorphism is when the males and females of a species have distinct physical features. This is common with sharks, with males usually being smaller than females and having distinct reproductive organs known as claspers. Bonnetheads have an additional dimorphic feature on the cephalofoil (that's the hammer head of the hammerhead sharks). Females have a smooth cephalofoil while males have a distinct bulge on the back edges. in addition, the cehalofoil of the bonnethead is smaller and more rounded than in other hammerheads. Other hammerheads don't use their pectoral fins very much and rely on using their cephalofoil to achieve pitch (up and down movement) and yaw (side to side movement). Because bonnetheads have smaller cephalofoils, they must rely on their pectoral fins more than other hammerheads, and theirs are therefore proportionately larger and stronger than the fins of other hammerheads. By hammerhead standards, the bonnethead is the guy with massive biceps.

The other major unique feature of bonnetheads is their diet. Bonnetheads eat mainly crustaceans, molluscs, and small fish, but also eat a large amount of seagrass. this makes them the only omnivorous sharks, with all others being strict carnivores. Scientists thought that the seagrass was used to protect their gut from shark shells, but recent studies have shown that they do actually digest around 50% of the seagrass and have enzymes in the hindgut that can break down cellulose, implying they do gain nutrition from seagrass.

Bonnetheads are one of several shark species capable of asexual reproduction. A female at the Henry Doorly Zoo in Nebraska produced a pup through through parthenogenesis. The pup's DNA was identical to the mother's. Bonnetheads also have the shortest gestation period of any shark at only 5-6 months and give live birth.

Bonnetheads were once classified as "Least Concern" by the IUCN. this led to it being highly targeted in fisheries, both commercial and recreational. In 2020, it was reclassified as "Endangered" due to massive population declines in the Caribbean, Central and South Atlantic, and most of their Pacific range, largely due to overfishing. As of late 2021, the IUCN now considered them the be "Largely Depleted, meaning their population is currently much smaller than it was historically.

[b33viemm]

Day 7: Genderfluid Bonnethead Shark

ID in alt Click for higher quality

Feel free to use with credit

[respect-the-locals]

🦈 Daily Shark Fact: 🦈

Bonnethead Sharks, also known as the Shovelhead shark, is a species of tropical shark, and is the smallest member of the hammerhead genus. Bonnetheads are the only shark species known to be omnivorous. They consume both animal and plant matters. Their diet is usually dominated by marine crustaceans, mostly blue crabs. They also eat mollusks, shrimp, and different species of small fishes. Seagrasses have also been found in their stomachs.