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Toady squid (Bufotheutis dioneomanus)

By AlexSone
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Order: Squids (Theutida)
Family: Angler squids (Lophiotheutidae)
Habitat: Pacific Ocean, depth of 500 – 3000 meters.

The family of lophiotheutid squids (“angler squids”) is widespread in the deep water area of the oceans of the world. These passive cephalopods are the ecological analogs of deepwater anglerfishes of Holocene, and in due course of evolution they got a distant similarity to these fish in their appearance. They almost lost all capability for the rapid reactive swimming and became passively drifting planktonic animals, capable of only swimming slowly using the strokes of their wide triangular fins.
Toady squid is widespread practically everywhere in Pacific Ocean, living in deep water layers far from the coasts and underwater mountains. The body length of this mollusc is approximately 20 cm not including tentacles. The passive way of life of toady squid had led to the striking changes in appearance of this mollusc in comparison with its rapidly swimming ancestors from upper layers of water. This species has short wide body, covered in flabby skin of pale gray color, which can both extend and get rumpled. The tentacles of this animal are short and wide, with well developed suckers and large corneous hooks at the tips. Their function is keeping of the grasped prey. Near the mouth suckers are reduced, but the corneous hooks are very large and are wide. 
This mollusc has good sight. It has large mobile eyes located at the edges of its flattened head. This squid easily notices the lights of deepwater animals in gloomy depths.
The trapping tentacle of toady squid is short and wide. Its trapping part can fold along like the leaf of Venus flytrap plant (Dionea muscipula). Sharp corneous hooks grow along the edges of this tentacle. Thin and flexible baiting tentacle can stretch out to the distance of one-and-a-half meters. When squid hunts, this tentacle “lures” prey from a distance with the help of the bait and grasps it with the “trap” of the trapping tentacle. The strong squeeze of trapping tentacle and corneous hooks stab the prey and kill it.
The beak of this squid is wide, and mouth can open very wide as well. The poisonous glands are not developed, because squid kills its prey with corneous hooks. This species is adapted to hunting large prey, whose mass can exceed its own one three times. Large animals are caught by the trapping tentacle right behind the head. When the prey is killed, squid grasps its head by tentacles and begins “stretching” onto its prey with the help of tentacle movements. Moving the tentacles, the predator crawls along the prey body from head to tail, keeping with the help of the hooks. Its mouth extends strongly, and the squid gradually swallows its prey, forcing it into a ring-like shape in its stomach. The lack of firm solid skeleton greatly helps this mollusc in carrying-out this specific method of feeding. After filling its stomach, the animal takes almost globular form and floats in the water depth, slightly moving its fins to keep stability. The prey is digested almost completely. 
This species of squid bears eggs on its own body. After the mating the male stays alive – its energy is enough to fertilize several females. The female lays several hundred thousands of very small eggs, encased in jelly-like shell looking like wide ribbon. It winds the clutch around the baiting tentacle and guards it during several months, driving off enemies with the help of trapping tentacle. The degeneration of the tissues of its body occurs at this time – the fat becomes completely used-up, the reduction of intestine and digestive glands takes place. Toward the end of the incubation the female becomes slow-moving and sluggish, but it reacts to the approaching of predators and makes threatening movements with its trapping tentacles. After the hatching of young squids it dies.
Young animals easily come to the surface because of drops of fat in their liver. They feed in upper layers of water on plankton crustaceans and fish fry. As they grow, the young toady squids migrate into the depths. The development of this species occurs very rapidly: at the age of 4 months, the young animal already has a body shape typical for the adult individuals, and it has half of the body length of adult mollusc. During their first year they reach the typical size of the adult individuals, and at the second year of life they become sexually mature.

Original drawing by Tim Morris
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