Oarfish are large, greatly elongated, pelagic lampriform fish belonging to the small family Regalecidae. They are found in all temperate to tropical oceans yet rarely seen. The occasional beachings of oarfish after storms, and their habit of lingering at the surface when sick or dying, make oarfish a probable source of many sea serpent tales like “The Serpent of Gloucester” and so forth. The tales that have come from these odd creatures have struck fear into the hearts of many people before they knew what it was. Although the larger species are considered game fish and are fished commercially to a minor extent, oarfish are rarely caught alive; their flesh is not well regarded due to its gelatinous consistency.
5. Frilled Shark
The frilled shark is found over the outer continental shelf and upper continental slope, generally near the bottom, though there is evidence of substantial upward movements. It has been caught as deep as 1,570 m (5,150 ft), although it is uncommon below 1,200 m (3,900 ft). In Suruga Bay, Japan it is most common at depths of 50-200 m (160-660 ft). Seldom observed, the frilled shark may capture prey by bending its body and lunging forward like a snake. The long, extremely flexible jaws enable it to swallow prey whole, while its many rows of small, needle-like teeth make it difficult for the prey to escape. It feeds mainly on cephalopods, leavened by bony fishes and other sharks.
Lampreys are an order of jawless fish, the adult of which is characterized by a toothed, funnel-like sucking mouth. Currently there are about 38 known species of lampreys. Although they are well known for boring into the flesh of other fish to suck their blood, in fact only a minority do so; only 18 species of lampreys are actually parasitic. They are found in most temperate regions except those in Africa. Their larvae (ammocoetes) have a low tolerance for high water temperatures, which may explain why they are not distributed in the tropics.
3. Horseshoe Crab
Horseshoe crabs are marine arthropods that live primarily in and around shallow ocean waters on soft sandy or muddy bottoms. They occasionally come onto shore to mate. They are commonly used as bait and in fertilizer. In recent years, a decline in the population has occurred as a consequence of coastal habitat destruction in Japan and overharvesting along the east coast of North America. Tetrodotoxin may be present in the roe of species inhabiting the waters of Thailand. Because of their origin 450 million years ago (Mya), horseshoe crabs are considered living fossils.
Nautilus is the common name of pelagic marine mollusks of the cephalopod family Nautilidae. Nautilidae, both extant and extinct, are characterized by involute or slightly evolute shells that are generally smooth, with compressed or depressed whorl sections, straight to sinuous sutures, and a tubular, generally central siphuncle. Having survived relatively unchanged for millions of years, nautiluses represent the only living members of the subclass Nautiloidea, and are often considered “living fossils.” The name “nautilus” originally referred to the pelagic octopuses of the genus Argonauta, otherwise known as paper nautiluses, as the ancients believed these animals used their two expanded arms as sails.
1. Goblin Shark
The goblin shark is a rare, poorly understood species of deep-sea shark. This pink-skinned animal has a distinctive profile with an elongated, flattened snout, and highly protrusible jaws containing prominent nail-like teeth. It is usually between 3 and 4 m (10 and 13 ft) long when mature, though it can grow considerably larger. Goblin sharks inhabit upper continental slopes, submarine canyons, and seamounts throughout the world at depths greater than 100 m (330 ft), with adults found deeper than juveniles. Various anatomical features of the goblin shark, such as its flabby body and small fins, suggest that it is sluggish in nature.