Mekong Giant Catfish

Fast Facts

Type: Fish

Diet: Herbivore

Average lifespan in the wild: More than 60 years

Size: Up to 10 ft (3 m)

Weight: Up to 650 lbs (295 kg)

Group name: School

Did you know? The largest freshwater fish ever recorded was a Mekong giant catfish caught in northern Thailand in 2005. It was nearly nine feet long (2.7 meters) and weighed 646 pounds (293 kilograms).

Protection status: Endangered
Size relative to a 6-ft (2-m) man:

Stingray Profile

Stingrays are commonly found in the shallow coastal waters of temperate seas. They spend the majority of their time inactive, partially buried in sand, often moving only with the sway of the tide. The stingray's coloration commonly reflects the seafloor's shading, camouflaging it from predatory sharks and larger rays. Their flattened bodies are composed of pectoral fins joined to their head and trunk with an infamous tail trailing behind.

While the stingray's eyes peer out from its dorsal side, its mouth, nostrils, and gill slits are situated on its underbelly. Its eyes are therefore not thought by scientists to play a considerable role in hunting. Like its shark relatives, the stingray is outfitted with electrical sensors called ampullae of Lorenzini. Located around the stingray's mouth, these organs sense the natural electrical charges of potential prey. Many rays have jaw teeth to enable them to crush mollusks such as clams, oysters, and mussels.

When they are inclined to move, most stingrays swim by undulating their bodies like a wave; others flap their sides like wings. The tail may also be used to maneuver in the water, but its primary purpose is protection.

The stingray's spine, or barb, can be ominously fashioned with serrated edges and a sharp point. The underside may produce venom, which can be fatal to humans, and which can remain deadly even after the stingray's death. In Greek mythology, Odysseus, the great king of Ithaca, was killed when his son, Telegonus, struck him using a spear tipped with the spine of a stingray.

Cyanea lamarckii

Maximun diametre: 30 cm, but in scandinavian waters rarely larger than 15 cm.

Appearance: Blue or yellow tone. It has a great many stinging tentacles that hang from the underside of the jellyfish. The four mouth arms, also hanging from the underside, are large and have many wrinkles and ripples.
Compare the Cyanea lamarckii with the lion´s mane, moon och rhizostome jellyfish.

Depth: Sea-surface to unknown depth.

Environment: Pelagic.

Misc: The medusae bud and loosen from the mature polyps in much the same way as in the lifecycle of the moon jellyfish. This occurs between January and March around the British Isles and southern North Sea. It is probably from these areas that the species has drifted when seen in other areas between the Bay of Biscay to Iceland. In scandinavian waters a minor number are seen between May and September.

Classification: Cyanea lamarckii is a member of the jellyfish group under the cnidarians.

Anthomedusae

Maximum height: 4 ,5 cm.

Appearance: The mouth is situated at the top of the tubular formationen that hangs from the middle of the "umbrella´s" underside. Along the inside edge is a peripheral crease, and the tantacles hang from the outer edge of the "umbrella". The anthomedusae tentacles are few, and the "umbrella" form is relatively high. The organs that produce eggs and sperms are placed by the mouth or on the stomach. The anthomedusae are usually transparent, although the nether parts of the mouth and the thicker areas of the tentacles are distinctly pigmented - black, brown, blue, red, yellow, green or other colour tones.
Compare the anthomedusae with the leptomedusae and other jellyfish.

Depth: Sea-level to unknown depth.

Environment: Pelagic.

Misc: The anthomedusae catches and eats small organisms and suspended remains from the surrounding water. These medusae do not sting enough to cause discomfort to people. Representatives of the anthomedusae group are found globally. The medusae stage is part of a life cycle that is similar to the leptomedusae.

Classification: The specimen in the picture above is probably of the species Neoturris pileata. Anthomedusae are part of the hydroid group under the cnidarians.

Compass jellyfish

Maximum diametre: approx. 20 cm.

Appearance: The compass jellyfish has a yellow-whitish colour with characteristic brown V-shaped lines on top of the "umbrella". The relatively large tentacles are few (24), and the four mouth arms are wrinkled and noticiably long.
Compare the compass jellyfish with the lion´s mane jellyfish.

Depth: From sea-level to unkown depth.

Environment: Pelagic.

Misc: Compass jellyfish change sex: first they are male, followed after by female. The medusae live mainly off other medusae, comb jellyfish and arrow worms. This species is a rarity in scandinavian waters, but medusae occasionally drift into nordic waters from the south during the summer and autumn.

Classification: The compass jellyfish is part of the jellyfish group under the cnidarians.

Comb jelly - Bolinopsis infundibulum

Maximum length: 15 cm.

Appearance: The jelly in Bolinopsis infundibulum is completely transparent, except with some adults that can have a milkish white colour. On the exterior of the oblong body, four long and four short comb-rows are situated. These can shimmer with the colours of the rainbow. Bolinopsis infundibulum has two small tentacles that are transformed into fringes along the sides of the creature. The mouth is surrounded by two flaps; while the other end of the body is drawn out into a obtuse point. Compare with the sea-gooseberry and other comb-jellies.

Depth: From the surface to unknown depth.

Environment: Pelagic.

Misc: Bolinopsis infundibulum is very fragile and almost always breaks when handled. On the two large flaps small organisms fasten and thereafter are transported to the mouth with the small flickering hairs. Certain fish, e.g. lump suckers and other comb-jellies feed on Bolinopsis infundibulum. Individual adults produce both eggs and sperm which they release into the water where fertilization takes place. It is possible to see Bolinopsis infundibulum shine in the dark.

Classification: Bolinopsis infundibulum is a member of the comb jelly group (ctenophora).

Leptomedusae

Maximum diameter: About 20 cm, but on exceptional occasions up to 30 cm.

Appearance: The mouth is situated at the top of the tubular formation that hangs down from the underside of the "umbrella". Along the inside edge of the "umbrella" is a peripheral crease and the tentacles hang down from the "umbrellas" outer edge. The leptomedusae have many tentacles, the number of which increase with age. The "umbrella" form is rather shallow, and on the underside, the organs that produce eggs and sperms are situated. The leptomedusae are usually transparent, but on occasions can be milky white or have a light blue, brown, red or violet tone. Even with transparent medusae, the sexual organs, stomach and tentacles can be light red, greenish or light brown.
Compare the leptomedusae with the anthomedusae and the moon jellyfish.

Depth: From sea-level to unknown depth.

Environment: Pelagic.

Misc: The leptomedusae catches and eats small organisms and suspended remains from the surrounding water. These medusae do not sting enough to cause discomfort to people. Medusae representatives are found globally. The medusa stage is part of a life cycle where even an attached stage is present and the medusae build colonies.

Classification: The above photo shows a jellyfish (Tima bairdii). Leptomedusae are part of the hydroid, group under the cnidarians.