Sperm whales (Physeter macrocephalus) are known to have the largest and heaviest brain of any other living creature. Though, the brain is not large relative to body size. Their huge, square shaped heads, which makes them easily distinguishable (up to one-third of the total body length), holds large quantities of a substance called spermaceti. They are dark grey to black in color and have wrinkled skin with a low hump instead of a dorsal fin. They have several thick, cone-shaped teeth which can weigh as much as 1 kilogram each. Sperm whales have a cosmopolitan distribution across the oceans. The species favorite prey is squid (including the giant squid and colossal squid), although they also eat a variety of deep-water fish, smaller sharks and skate. These whales can swim to extreme depths, 2000m and possibly 3000m and remain submerged for more than a hour.
Female sperm whales are often spotted in groups (called pods) of about a dozen individuals and their young, whereas male sperm whales, which are much larger than females in size, may roam solo or move from group to group. Female sperm whales give birth every 3 to 6 years, and care for the calves for more than a decade. The gestation period requires 14 to 16 months, producing a single calf. Sperm whales can live 70 years or more.
Entanglement in fishing nets and collisions with ships represent the greatest threats to the sperm whale population presently. Other present threats include ingestion of marine debris, ocean noise, and chemical pollution. The IUCN regards the sperm whale as being "vulnerable", whereas the U.S. lists them as endangered.
Image and Info: National Geographic and Wikipedia
No comments:
Post a Comment