798 Views Share:
Favorite Images of Seals & Sealions #1
Animals list created by kathy
A list of my favorite images of seals and sealions.
List #2 may be viewed here: www.listal.com/list/favorite-images-seals-sealions
Pinnipeds, colloquially known as seals,are a widely distributed and diverse clade of fin-footed, semiaquatic marine mammals.
They comprise the extant families Odobenidae (whose only living member is the walrus), Otariidae (the eared seals: sea lions and fur seals) and Phocidae (the earless or true seals).
There are 33 extant species of pinnipeds, and more than 50 extinct species have been described from fossils. While seals were historically thought to have descended from two ancestral lines, molecular evidence supports them as a monophyletic lineage (descended from one ancestral line).
Pinnipeds belong to the order Carnivora and their closest living relatives are bears and musteloids (weasels, raccoons and skunks).
Seals range in size from the 1 m (3 ft 3 in) and 45 kg (99 lb) Baikal seal to the 5 m (16 ft) and 3,200 kg (7,100 lb) southern elephant seal, which is also the largest carnivoran. Several species exhibit sexual dimorphism.
They have streamlined bodies and four limbs that are modified into flippers. Though not as fast in the water as dolphins, seals are more flexible and agile. Otariids use their front limbs primarily to propel themselves through the water, while phocids and walruses use their hind limbs.
Otariids and walruses have hind limbs that can be pulled under the body and used as legs on land. By comparison, terrestrial locomotion by phocids is more cumbersome. Otariids have visible external ears, while phocids and walruses lack these.
Pinnipeds have well-developed senses—their eyesight and hearing are adapted for both air and water, and they have an advanced tactile system in their whiskers or vibrissae. Some species are well adapted for diving to great depths.
They have a layer of fat, or blubber under the skin to keep warm in the cold water, and, other than the walrus, all species are covered in fur.
37 votesMy Aquatic Animals Collection (32 lists)
list by kathy
Published 3 years, 8 months ago
5 votesAnimals - S (31 lists)
list by kathy
Published 10 months, 3 weeks ago