Marine Species under Threat: Humphead wrasse | Napoleon wrasse

The humphead wrasse, Cheilinus undulatus, is a species of wrasse mainly found on coral reefs in the Indo-Pacific region. It is one of the largest coral reef fishes and occurs patchily throughout much of the Indo-Pacific region. The fish is also known as the Māori wrasse, Napoleon wrasse, Napoleon fish and Napoleonfish.

The humphead wrasse has thick, fleshy lips, and a hump forms on its head above the eyes, becoming more prominent as the fish ages, hence its name. Males range from a bright electric blue to pale green, a purplish blue, or a relatively dull blue/green. Juveniles and females are red-orange above, and red-orange to white below.

This species reaches a maximum length of more than 2m and up to 190kg in weight but some males grow very large, with one unconfirmed report of a humphead wrasse that was 7.75 ft (2.29 m) long and weighed 420 lbs (190.5 kg). Sexual maturation of this species takes up to 5-7 years.

Humphead wrasse feed primarily on molluscs, fish, sea urchins, crustaceans, echinoderms, and other invertebrates, using their strong teeth. The species may be one of the few predators of the toxic crown of thorns starfish, boxfish and sea hares.

The humphead is found in the Indo-Pacific, from the Red Sea to South Africa and to the Tuamoto Islands (Polynesia), north to the Ryukyu Islands (south-west Japan), and south to New Caledonia. 

Marine Species under Threat: Hawksbill sea turtle

The hawksbill sea turtle (Eretmochelys imbricata) is a critically endangered sea turtle belonging to the family Cheloniidae. Hawksbills are named for their narrow, pointed beak. It is the only extant species in the genus Eretmochelys.

The hawksbill sea turtle also have a distinctive pattern of overlapping scales on their shells that form a serrated-look on the edges. These colored and patterned shells make them highly-valuable and commonly sold as "tortoiseshell" in markets.

Adult hawksbill sea turtles have been known to grow up to 1 m (3 ft) in length, weighing around 80 kg (180 lb) on average. The heaviest hawksbill ever captured was measured to be 127 kg (280 lb).

Hawksbill sea turtles have a wide range, found predominantly in tropical reefs of the Indian, Pacific, and Atlantic Oceans. Of all the sea turtle species, E. imbricata is the one most associated with warm tropical waters. Two major subpopulations are acknowledged to exist, the Atlantic and Indo-Pacific subpopulations.

Quick Facts about the hawksbill sea turtle:

Type: Reptile

Diet: Carnivore

Average life span in the wild: 30 to 50 years (EST.)

Size: 24 to 45 in (62.5 to 114 cm)

Weight: 100 to 150 lbs (45 to 68 kg)

Protection status: Endangered

Size: Size relative to a 6-ft (2-m)

Like many sea turtles, hawksbills are a critically endangered species due mostly to human impact. Hawksbill eggs are still eaten around the world despite the turtle’s international protected status, and they are often killed for their flesh and their stunning shells. These graceful sea turtles are also threatened by accidental capture in fishing nets.

While they are omnivorous, sea sponges are the principal food of hawksbill sea turtles. Sponges constitute 70–95% of their diets in the Caribbean. However, like many spongivores, they feed only on select species, ignoring many others. Some of the sponges they eat, such as Aaptos aaptos, Chondrilla nucula, Tethya actinia, Spheciospongia vesparium, and Suberites domuncula, are highly (often lethally) toxic to other organisms.

Marine Species under Threat: Polar bear | Polar bear pictures

The polar bear, Ursus maritimus, or the sea bear, started to evolve about five million years ago from brown bear ancestors. Unlike their land-based cousins, polar bears are superbly adapted for survival in the Far North on a sea ice habitat. The polar bear is classified as a vulnerable species, with eight of the nineteen

polar bear subpopulations in decline.

The polar bear (Ursus maritimus) is a carnivorous bear whose native range lies largely within the Arctic Circle, encompassing the Arctic Ocean, its surrounding seas and surrounding land masses. It is a large bear, approximately the same size as the omnivorous Kodiak bear (Ursus arctos middendorffi). A boar (adult male) weighs around 350–700 kg (770–1,540 lb), while a sow (adult female) is about half that size.  At birth, polar bear cubs are 12 to 14 inches long and weigh around one pound.

Polar bears are the largest land carnivores in the world, rivaled only by the Kodiak brown bears of southwestern Alaska. Polar bears sit at the top of the food chain in the biologically rich Arctic. The most carnivorous of the bear species, polar bears feed primarily on the fat of ice-dependent seals. The remains of these seals provide food for many other Arctic wildlife species, giving polar bears a vital role in their ecosystem.

Unlike grizzly bears, polar bears are not territorial. Although stereotyped as being voraciously aggressive, they are normally cautious in confrontations, and often choose to escape rather than fight.

Polar bears feed almost exclusively on ringed seals and bearded seals. Polar bears usually hunt ringed seals by waiting for the seals surface to breathe at openings (leads) in the ice or at breathing holes called aglus. They are also known to eat walrus, beluga whale and bowhead whale carcasses, birds’ eggs, and (rarely) vegetation. Polar bears travel great distances in search of prey.

Scientific classification of Polar bears:

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Carnivora

Family: Ursidae

Genus: Ursus

Species: U. maritimus

Marine Species under Threat: Dugong

The dugong (Dugong dugon) is a large marine mammal which, together with the manatees, is one of four living species of the order Sirenia. It is the only living representative of the once-diverse family Dugongidae; its closest modern relative, Steller's sea cow (Hydrodamalis gigas), was hunted to extinction in the 18th century.

Dugongs are related to manatees and are similar in appearance and behavior— though the dugong's tail is fluked like a whale's. Both are related to the elephant, although the giant land animal is not at all similar in appearance or behavior. Some believe that dugongs were the inspiration for ancient seafaring tales of mermaids and sirens.

The dugong is also the only sirenian in its range, which spans the waters of at least 37 countries throughout the Indo-Pacific, though the majority of dugongs live in the northern waters of Australia between Shark Bay and Moreton Bay. The dugong is the only strictly marine herbivorous mammal, as all species of manatee use fresh water to some degree.

These enormous vegetarians can be found in warm coastal waters from East Africa to Australia, including the Red Sea, Indian Ocean, and Pacific.

These languid animals make an easy target for coastal hunters, and they were long sought for their meat, oil, skin, bones, and teeth. Dugongs are now legally protected throughout their range, but their populations are still in a tenuous state.

Quick stats and scientific classification of Dugong:

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Sirenia

Family: Dugongidae (Gray, 1821)

Subfamily: Dugonginae (Simpson, 1932)

Genus: Dugong (Lacépède, 1799)

Species: D. dugon 

Type: Mammal

Diet: Herbivore

Average life span in the wild: 70 years

Size: 8 to 10 ft (2.4 to 3 m)

Weight: 510 to 1,100 lbs (231 to 499 kg)

Group name: Herd

Protection status: Threatened

Size: relative to a 6-ft (2-m)

Marine Species under Threat: Blue Whale

The blue whale (Balaenoptera musculus), the largest animal on the planet is a marine mammal belonging to the baleen whales (Mysticeti). At 30 metres (98 ft) in length and 170 tones (190 short tons) or more in weight, it is the largest existing animal and the heaviest that ever existed.

The blue whale, i.e. is weighing as much as 200 tons (approximately 33 elephants). The blue whale has a heart the size of a Volkswagen Beetle. Its stomach can hold one ton of krill and it needs to eat about four tons of krill each day. They are the loudest animals on Earth and are even louder than a jet engine. Their calls reach 188 decibels, while a jet reaches 140 decibels. Their low frequency whistle can be heard for hundreds of miles and is probably used to attract other blue whales.

Blue whales have a long-body and comparatively slender shape, a broad, flat "rostrum" when viewed from above, a proportionately smaller dorsal fin than other baleen whales, and a mottled gray color pattern that appears light blue (hence, the "blue" whale) when seen through the water.

Blue whales are found worldwide, from sub-polar to sub-tropical latitudes. Pole ward movements in spring allow the whales to take advantage of high zooplankton production in summer. Although blue whales are found in coastal waters, they are thought to occur generally more offshore than other whales.

Main stats/ Species Description of Blue Whale:

Weight:	up to 330,000 pounds (150,000 kg)
Length:	up to nearly 110 feet (33 m), depending on location (blue whales are largest in the Antarctic)
Appearance:	long body with mottled gray color pattern that appears light blue when seen through the water
Lifespan:	unknown, but sexually mature around 5-15 years
Diet:	primarily krill
Behavior:	births and mating mostly take place in the winter