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California Swelling Shark (Cephaloscyllium ventriosum)


Cephaloscyllium ventriosum (Garman, 1880)
Californian bloating shark, Californian bloating cat shark, Californian big-headed shark, Californian big-headed cat shark, Californian cat-headed shark, Californian big-bellied shark, Californian big-bellied shark, Chilean cat-headed shark, Chilean big-bellied
California swell shark, swellshark
Catulus uter Jordan & Gilbert, 1896
Cephaloscyllium uter Roedel & Ripley, 1950
Scyliorhinus ventriosus regan, 1908
Scyllium ventriosum garman, 1880

Initially, a California swelling shark was described in 1880 by the American scientist Garman (Samuel Walton Garman - Samuel Walton Garman, 1843 - 1927, an American herpetologist, paleontologist and ichthyologist, he studied under Louis Agassiz, received a diploma in 1872, accompanied Edward Cope in 1872 in Wyoming, to collect fossils (fossils), with Louis Agassis made a research trip to the Strait of Magellan, since 1873 he worked at the Museum of Comparative Zoology at Harvard University, his work concerned the classification of fish, especially sharks, as well as reptiles and amphibians), like Scyllium ventriosum, however, later it was ranked as Cephaloscyllium.
The genus name comes from the Greek words κεφαλι (kephale) - “head” and σκυλοψαρο (skylopsaro) - “sea dog”, indicates that it is a small shark with a wide and flattened head. The species epithet ventriosum means "pot-bellied", comes from the Latin words venter - "belly" and the suffix osum - "full" and reflects the ability of this shark to swell in case of danger.
California swelling sharks live in the eastern Pacific Ocean (40 ° N - 37 ° S, 126 ° W - 71 ° W), off the coast of California in the Gulf of California and at the southern tip of Mexico . These sharks live on the continental shelf, and in tropical waters are found from 5 m from the surface of the water to a depth of 457 m. They prefer to stay on the bottom, which is covered with algae. Off the coast of California, they share the area with the California bull shark (Heterodontus francisci), but unlike the latter, they are much more tolerant of water temperatures below 20 °.
The maximum length is 110 cm. The first dorsal fin is rounded and located above the ventral fins. The base of the second dorsal fin is opposite the anal fins. Fins are light brown in color with dark markings. The body is dotted with dark dots. As a rule, young individuals are lighter than adults. In color, this species resembles a California trident shark. California swelling sharks have very small and narrow gill slits. They have large golden eyes. In the mouth, 55-60 tiny teeth on each jaw.
Like other big-headed sharks, California bloated sharks are able to pump with water and bloat in case of danger, in this way they wedge in the crevices, not allowing themselves to be caught, and even frighten off the predator. To do this, they bend the body in the form of the letter U, grab their mouth with their mouths and suck water through their mouths into the stomach. If they are pulled out of the water, they swallow air, and when blown away, they make sounds resembling a dog barking.
These sharks lead a nocturnal lifestyle, and during the day they sleep in crevices and caves. Cephalopods, crustaceans, and small fish make up their diet. Hunting, they lie at the bottom and wait for the prey to approach them a few centimeters away, and then attack. Another hunting tactic is that sharks lie on the bottom of the ocean, waiting for the little fish to swim in their mouth. In addition, they empty lobster traps. California bloating sharks are sociable in relation to their counterparts, you can often watch them sleep on top of each other.
This species reproduces by laying two eggs at a time, enclosed in greenish or amber capsules. At the corners of the capsule there are spiral antennae, with which the capsule is attached to underwater objects. Studies have shown that the length of the antennae depends on the strength of the surf in the habitat. The size of the capsule is approximately 2.5-5.1 cm in width and 7.6-13 cm in length. The term of development of the embryo varies depending on the temperature of the water and ranges from 7.5 to 12 months. Hatching newborn sharks immediately begin to feed. Females reach puberty at a length of 70 cm, and males - 73 cm.
California swelling shark is not dangerous to humans. Faced with a shark under water, it will remain motionless, but if disturbed, it will increase in 2 times in size, pouting with water. They adapt well to captivity, they are often kept in public aquariums, where they live for several years. Sometimes by-catch they fall into the net, but these sharks are most often released back into the water, as their meat has an unpleasant taste. Once trapped in lobster traps, California swelling sharks are likely to die. The International Union for Conservation of Nature has rated the conservation status of this species as “Least Concerned”.

Cephaloscyllium ventriosum (Garman, 1880) - Chilean cat-headed shark
Scyllium ventriosum Garman, 1880, Catulus uter Jordan et Evermann, 1896, Scyliorhinus ventriosus Regan, 1908, Cephaloscyllium uter Roedel & Ripley, 1950, Cox, 1963, Pinchuk, 1972
Body color is grayish with darker spots of various sizes on the sides and especially on the back. The head is large, at least 1/5 of the length of the body.

The beginning of the base of the ventral fins lies behind the middle of the body (see Table 15).

Numerous small teeth, dental formula 55 - 60 - 0 - 55 - 60/55 - 60 - 0 - 55 - 60.
Biology. Maximum body length 1 m. Oviparous. The size of the egg capsule is from 90x28 to 125x55 mm. The length of juveniles with hatching is 14-15 cm. Obviously, benthophages.
Spread. Along the Pacific coast of America (from Southern California to Chile) at depths of up to 400 m. A number of independent populations are found within the range.
Economic value. Sometimes like by-catch.

Life of animals. Volume 4. Pisces Edited by Professor T. S. Rass 1971

The Californian bloating shark (Cephaloscyllium uter), common in coastal waters off the Pacific coast of Mexico and the United States, also belongs to the cat shark family. It is quite brightly colored in tan and has black spots and stripes on the body. This shark, reaching 1 m in length, feeds on fish, sometimes capturing a fairly large prey. Interestingly, when pulled out of the water, a California shark can swallow air and inflate its belly, which gives it a very strange look. Sometimes bloated sharks were observed floating on the surface of the water.

California Inflatable Cat Shark

The species epithet of this shark, “ventriosum”, means “pot-bellied” and indicates the ability to inflate a stomach in case of danger. This property is inherent in all species of big-headed cat sharks and, according to zoologists, helps them escape from predators. The fish, which has inflated the stomach to a spherical state, looks somewhat frightening, which keeps the enemy from attacking. And jamming of the body in such an unusual way between the walls of the shelter (cracks or crevices) prevents the shark from being removed from the shelter.

California inflatable shark refers to one of the species of large-headed shark cats that have been known to science for a long time. As early as 1880, the species was described as Scyllium ventriosum. When the taxonomists identified the genus Cephaloscyllium (big-headed sharks) in the family of cat sharks, the Californian variety took the assigned place.

This predatory fish lives in the east of the Pacific Ocean, along the coast of California, in the Gulf of California and off the coast of Mexico. The range is limited to latitudes of 40 degrees. from. w. - 37 deg. Yu. w. Information on the capture of this shark off the Pacific coast of South America (Chile) requires confirmation.
The deepest range, most often settled by a California inflating shark, is from the surface to a depth of 40 m.However, the facts of capture are also known from a depth of more than 400 m.They prefer rocky and stony soils with natural shelters, densely covered with aquatic vegetation.

Refers to relatively large species of cat sharks. The maximum documented size of this fish is 110 cm. The usual sizes do not exceed a meter length.

The appearance of this shark is characterized by a full cylindrical body and a short wide head. The snout is wide, roundish-angular and very short. The eyes are relatively high on the head. They are almond-shaped, protected by migratory membranes and have slit-shaped pupils. The front nasal leather folds (nasal valves) are wide, triangular in shape. The mouth is large, curved arch. If we compare the relative width of the mouth of a great white shark and an inflated one, the latter wins noticeably in the size of its mouth. There are no labial folds. The teeth are small, three-peaked, as in other sharks of the genus Cephaloscyllium.

The anterior dorsal fin is larger than the posterior, located on the body just behind the low ventral fins. In males, the abdominal fins form short and thick genitals. The pectoral fins are large, wide, with rounded apices.
The caudal fin is heterocercal in shape, the lower lobe is poorly developed. At the tip of the upper lobe there is a deep ventral incision.

Body color mottled. The overall background is tan. Numerous light and dark spots are scattered throughout the body and fins. On the upper side of the body there are dark saddle spots. The ventral side of the body and the underside of the head are light with low contrast dark spots. The edges of the fins do not have a pronounced edging.

The California Swelling Shark is a sedentary, sluggish bottom predator, more active in the dark. In the afternoon he prefers to relax in some kind of shelter (cave, between the stones), lying on the ground or among algae. Sometimes such resting sharks form clusters, and can even be placed on top of each other.
At night, she begins the hunt for her favorite prey — crustaceans, mollusks, and small bony fish. At the same time, he often uses ambush tactics - lying on the bottom with his mouth ajar, waiting for a potential victim to approach the zone of action of the buccal pump. The predator either simply sucks the gaping prey in the mouth, or grabs it in the jaw with a short throw.
The structure of the dental apparatus of this shark does not involve chewing food or biting off pieces of it, so the victim (sometimes even quite large) is swallowed whole. The predator easily copes with the shells of crustaceans using multi-vertex teeth.

The natural enemies of the California variety of inflating sharks are large marine predators - sharks, stingrays, marine pinnipeds, bony predatory fish, as well as parasites - from worms and leeches, to microscopic ones.

Big-headed (inflating) sharks have developed a curious way of protection against a potential enemy. They curl up, capturing the caudal fin in the teeth and, swallowing water, greatly increase their body in volume. A shark inflated in this way hopes to scare away large predators.
If a shark inflates a body in a cave or crevice, wedging it between the walls of the shelter, it is very difficult to pull it out. When the threat from the enemy disappears, the shark releases water from the stomach with a characteristic sound resembling a dog barking, and its body takes its usual shape.
For this property, these sharks are called pouting, balloon sharks, pregnant sharks, steam sharks, etc.

These fish breed eggs. The female lays a pair of eggs enclosed in capsules of yellowish or greenish color up to 13 cm long at the time of ingestion. The eggs are attached to the bottom substrate using special twisted antennae located at the corners of the capsule.
The incubation period can last up to a year (depending on water temperature). Fry at birth are at least 15 cm long and from the first day of life begin to independently obtain food.
Males become sexually mature with a length of over 73 cm, females - more than 70 cm.

California inflated sharks do not represent commercial value. They often fall into bottom fishing tackle as by-catch, but are usually thrown into the sea, as the meat of these fish is not appreciated due to unpleasant taste. Inflated sharks are very tenacious and can do without water for a long time, so discarded individuals usually survive.
These small sharks take root well in captivity and can live in an aquarium of sufficient capacity for several years.
IUCN (International Union for Conservation of Nature) rated the status of the species as least worrisome (LC).

For humans, the California big-headed (inflating) shark is not dangerous. Usually she does not pay attention to a diver or diver floating nearby and lies motionless. When you try to make contact, it turns into a ring and instantly inflates.