WHALESE B O O K F O R F A N S

KAREN CASTILLO & ANDRÉS GÓNGORA

Copyright © 2016 Datamatic, S.C.

All rights reserved. This book or any portion thereofmay not be reproduced or used in any manner whatsoever without the express written permission of the publisher except for the use of brief quotations in a book review.

First Edition, 2016

Datamatic, S.C.Miami, FL.

www.whale-world.com

Text and research: Karen CastilloDesign: Andrés Góngora.Review: Berenice Lorenzo.Production: Sergio Góngora.

Editorial: Datamatic, S.C.

Photos: courtesy of Pixabay and the respective authors.

All images rights are property of their authors as listed in Pixabay.

Bioexpedition and its logo are trademarks of Datamatic, S.C.

INTRODUCTION

Some toothed cetaceans are often called whales, like the sperm whale, the orca, and the beluga.

Among the marine mammals, whales have a leading place for features like their size. Although they are animals adapted to aquatic life, they breathe through their lungs, give birth to live offspring and breastfeed like most land mammals.

Whales belong to the infra-order cetaceans, a group that includes dolphins and porpoises.

The word "whale" is just a common name applied to several species, but there are toothed whales or Odontoceti; and baleen whales, or Mysticeti. Although rigorously only four species of the genera Balaena and Eubalaena, are whales, in practice, all baleen whales, and even some toothed whales are called whales.

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There are 15 species of baleen whales:

Pygmy right whale.

Gray whale.

Fin whale.

Humpback whale.

Bryde's whale.

Eden's whale.

Omura's whale.

Sei whale.

Blue whale.

Common minke whale.

Southern minke whale.

North Atlantic right whale.

Southern right whale.

North Pacific right whale.

Bowhead whale.

They all are huge animals compared to most marine creatures which have massive bodies and usually slow movements. They are essential for the ocean food chain, for being on the top of it.

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DISTRIBUTION & HABITAT

The closest living relatives of whales are hippos as they both descended from a semi-aquatic ancestor.

Whales live in all oceans of the world, in different environments and habitats. Some spend their lives in the icy waters of the poles, while others live in warmer habitats near the tropics. Similarly, some whale species reside near coastal areas while some others dwell mainly in open waters and rarely or never venture close to the coast.

Whale distribution depends on many factors related to their anatomy, their evolution, their diet and other requirements. Some species have populations in all oceans around the world; these are the cosmopolitan species, like the blue whale, which inhabits all the great oceans, although they do not venture into some small seas.

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By contrast, only some whales live in small or very specific regions of the world and never leave them, like the North Atlantic right whale, which inhabits only in some areas of the Atlantic Ocean.

Several whale species tend to migrate at certain seasons, either toward the polar regions in the summer looking for food or to the tropics to give birth during the winter, but even among migratory species, there are some who prefer to stay in places close to the coasts.

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I

ANATOMY

If there is something particular about the anatomy of baleen whales, it is their large size. Undeniable proof of this is the blue whale, the world's biggest animal, with its 30 meters long. However, there are smaller species like the pygmy right whale (Caperea marginata), which reaches at most 6.5 meters long.

All species have a fusiform body, with a thick center and thinner ends. They have two pectoral fins and tail flukes that move up and down. Some have a fin on the back. Their head is broad, and at the top, they have two spiracles, which are the openings where they breathe and get oxygen; they hermetically close them when submerged. Once the air enters the spiracles, it goes into the lungs. Two indentations in the head, almost imperceptible at plain sight, drive sounds to the ear canals.

Baleen whales have baleen instead of teeth. They are long and flexible structures composed of a protein called keratin, which filter water out and retain the food. Some have a few longitudinal folds in the lower part of their body, which expand when the whales introduce a large volume of water in their mouth.

Their skin is soft and almost smooth, but usually, display marks or scars as a result of possible fights with other whales or animals or even attached parasites. An oily substance covers the skin which reduces water friction and resistance when moving.

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The body of whales has a lighter color on the bottom, this allows them to blend with the water surface if seen from below.

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FEEDING

Baleen whales can consume each day about 4% of their body weight.

Baleen whales can feed on a wide variety of animals, usually small fish and plankton. Although toothed whales have adapted to hold their food, baleen whales feed on zooplankton and krill, and to a lesser extent include small fish, copepods, and squid.

Baleens act as a filter; they filter the water out and keep small organisms trapped in them, and then the whale swallows the trapped food. A baleen whale can filter massive amounts of food in this structure.

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Not all species get their food the same way. Many, swim with their mouth open through extensive accumulations of zooplankton, but gray whales prefer to suck the water and the sand of the ocean floor, to catch small benthic creatures.

Their size could suggest that whales eat very often, but most baleen whales spend only 4 to 5 months a year for feeding and survive the rest of the year thanks to the abundant reserves of fat and some occasions when they capture food.

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BEHAVIOR

Unlike dolphins, baleen whales are less social, because many of them spend most of their lives alone or accompanied only by their offspring. Sometimes they form temporary groups, but they are not large herds where they stay throughout their existence. Occasionally, they travel in small groups and meet in feeding areas.

Whale are intelligent creatures, gifted with the ability to communicate with each other through sounds, movements and body postures. Some whales hit the water with their tails or fins as a warning to their peers or to show excitement or aggression. Humpback whales stand out for their impressive moves and leaps out of the water, as well as their melodic songs, frequent during the breeding season. All whales can produce sounds to communicate.

As mammals, baleen whales give birth to live young after a long gestation period and subsequently breastfeed them. They are polygamous, and females usually have a single calf after a gestation that lasts between 10 to 14 months, depending on the species. Youngs are unable to take care of themselves, so their mothers do it and continuously feed them for several months.

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Whales cannot sleep as many animals, but they usually rest with half of the brain active.

Mothers and calves create a close bond that can extend after the weaning, which usually occurs around the first birthday of the calves. They gain weight quickly, thanks to the fat-rich milk from their mother.

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THE BLUE WHALE

Blue whales have a big appetite. An adult can consume 3,600 kilo-grams of krill in a day.

THE BLUE WHALE.

Balaenoptera musculus.

This remarkable animal has the largest body of all living beings on Earth, and his heart is so colossal that exceeds the size of several large animals. A blue whale can measure up to 30 meters long and weigh up to 173 tons, exceeding the size of most known dinosaur fossils. Females tend to be larger than males.

Blue whales live in all oceans of the world and may even reach a small part of the Arctic, but their largest populations dwell in particular regions such as the northeast Pacific Ocean. This species has three subspecies: Balaenoptera musculus musculus, Balaenoptera musculus intermedia, and Balaenoptera musculus brevicauda, distributed in particular areas each one. They usually

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spend more time in the open ocean, but sometimes they get close to coastal waters.

These cetaceans differ from other baleen whales by featuring an elongated and relatively thin body, and a flat head on the top. Their diet is almost exclusively based on krill, although they do not discard tiny copepods and small fish. During the day, they go deep into the ocean to catch their food, and during the night they change their strategy and stay near the surface to feed.

The blue whale is a mammal that does not generate many offspring, but only one at a time. Males can compete to mate with a female, which sometimes leads to fights. After 10 to 12 months of gestation, a calf is born with about 7 meters long, and during the following months is breastfed and cared for with exceptional dedication by his mother.

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GRAY WHALE

THE GRAY WHALE.

Eschrichtius robustus.

The easiest way to recognize a gray whale is by the presence of a substantial amount of parasites and other animals attached to their grayish skin. The most common is a type of barnacle known as "whale lice" which is embedded mostly in the head and makes their skin look with whitish and orange spots.

This species inhabits shallow coastal waters of the North Pacific Ocean and adjacent waters and rarely reaches waters of the Arctic Ocean. Like other baleen whales, it feeds by filtering, but instead of swimming with their mouth open, they usually go to the ocean floor and sucks a lot of sediment, filter the food out with their baleen and then take off the water and the sandy material. Their main foods are benthic crustaceans.

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Gray whales are curious animals, and it is common to see them taking their head out of the water to watch the boats. Sometimes they breach or jump out of the water, possibly as a form of communication or to remove the parasites from their skin. They are seen often traveling alone or in small groups; higher concentrations are only for feeding or reproduction. It is a migratory species and is probably the mammal with the longest migration.

Currently, the gray whale is not endangered, but for a long time has been affected by commercial whaling, which ended its Atlantic Ocean populations several centuries ago.

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Gray whales were called "devil fish" once because of their violent reactions to defend their young and themselves from attacks either from humans or other predators.

HUMPBACK WHALE

THE HUMPBACK WHALE.

Megaptera novaeangliae.

The humpback whale has a robust body and a head with lumps or bumps and large pectoral fins that reach up to one-third of their body length. Adults are 12 to 16 meters long and weigh between 25 and 30 metric tons. It is common that they have attached parasites in their head.

This species is found in all oceans and during summer their number increases in the Antarctic region. They prefer shallow habitats. When dwelling Antarctic waters they feed on krill, but their diet also includes small fish such as Atlantic salmon, capelin, herring, mackerel, and haddock. One of their most popular hunting methods includes blowing to form bubble columns that enclose their prey.

During summer, humpback whales travel to feeding areas located at high latitudes, and during winter they migrate to breeding areas in tropical or subtropical waters. However, the population of the Arabian Sea stays in the region throughout the year. During the breeding and gestation period, they survive on their fat reserves, as they only feed during the summer.

Like most baleen whales, they only have one offspring per litter, born after a gestation period of 11-11.5 months. The mother feeds her calf with breast milk for several months, and when summer arrives, they travel together to the feeding areas.

The humpback whales are not endangered now, but they are continuously threatened by commercial fishing and bycatch.

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Only humpback whale males produce songs. The general belief is that they do it to attract females during the breeding season.

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THREATS

Whales have no natural predators, but young or weak individuals can fall prey to large carnivores, especially sharks.

THREATS.

For a long time, whales have been threatened by fishing and other human activities. Many die after colliding with large ships and because of the pollution of their habitat, while excessive noise and the effects of climate change on oceans affect the availability of their food and can alter their migration routes. At present, the blue whale (Balaenoptera musculus), the fin whale (Balaenoptera physalus), the North Atlantic right whale (Eubalaena glacialis), the northern Pacific right whale (japonica Eubalaena) and the sei whale (Balaenoptera borealis) are in danger of extinction.

Hunting of whales and other cetaceans during the XVII, XVIII, XIX and XX

centuries was part of an ordinary economic activity, since fat, meat, beards and other body parts were traded. But over the years their population began to decline, raising concerns among people that started to protect them. In 1982 the International Whaling Commission imposed a moratorium to end commercial whaling, which came into effect in 1985-1986.

Not all countries agreed to end commercial whaling, despite the risks that this entails. However, many organizations are struggling to prevent massive deaths of these magnificent animals.

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