Tag Archive: baleen


TAXONOMY
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Cetartiodactyla
Family: Eschrichtiidae

Genus/species: Eschrichtius robustus

GENERAL CHARACTERISTICS: This species is mottled dark to light grey and is encrusted with patches of barnacles and orange whale lice. Unlike Humpback whales, Grey whales lack a dorsal fin and instead has a series of bumps along a dorsal ridge on the final third of the back. Gray whales have small, paddle-shaped flippers, compared to the large white flippers of Humpback whales.
Length to 14 m (46 ft).
Weigh to 36,000 kg (79,300 pounds).

(see links below for live animal photos under references).

Grey Whale18204939731_f69eecb43a_k

DISTRIBUTION/HABITAT: Now found only in the North Pacific and adjacent waters. E. robustus are primarily bottom feeders and are thus restricted to shallow continental shelf waters for feeding.

DIET: The only cetacean to feed by straining the sediment on the sea floor. mainly for bottom-dwelling crustaceans but also worms and mollusks. Water, sand and mud are expelled through the baleen and food is then swallowed.
Sufficient fat reserves are stored in the feeding grounds to allow individuals to go without food during the breeding season; on return to the feeding grounds about a third of the body weight may have been lost.

REPRODUCTION: The breeding cycle last two years. Gestation takes about 13 months and the single calf is then suckled for a further seven months. The mother may have to hold the calf near the surface to help it to breathe during the first few hours after birth.

E. robustus makes the longest migration of any mammal known, each autumn and spring they pass between their Arctic summer feeding grounds and the mating and calving lagoons in Baja California.
Round-trip up to 20,400 kilometres (12,676 miles).

LONGEVITY: 25 to 80 years.

PREDATION: The only non-human predator of Gray whales is the Killer whale with up to 18% of all Gray whales showing evidence of an Orca attack.

CONSERVATION: IUCN RED LIST Least Concern (LC)
The Eastern North Pacific population has made a significant recovery since 1947 when whaling stopped for this species and now they number between 19,000 – 23,000, which may be close to their original population size.
Three gray whale breeding lagoons in Mexico enjoy some protection in the form of limitations on boating, fishing and coastal development.

Threats: Collisions with ships, entanglement in fishing nets and pollution. Habitat degradation resulting from drilling and dredging is also a problem.

REMARKS: The California Academy’s Gray whale was a juvenile that beached in Baja California in 1966. It would have been about 35 feet long while alive. The two small, hanging, isolated bones towards the tail are remnants of pelvic bones, evidence that whales descended from four-legged land mammals that returned to the ocean about 53 million years ago.

References

California Academy of Sciences Docent program Whale  information March 2015

IUCN Red List www.iucnredlist.org/details/8097/0

ARKive  www.arkive.org/gray-whale/eschrichtius-robustus/

Ron’s flickr link www.flickr.com/photos/cas_docents/18204939731/in/album-72…

Shirihai, H & Jarrett (2006) Whales Dolphins and Other Marine Mammals of the World Princeton University Press.

Evans, P & Weinrich, M (2002) Whales Dolphins and Porpoises D K London New York Munich Melbourne and Delhi.

Reeves, R, R, et al (2002) Guide to Marine Mammals of the World  Chanticleer Press, Inc.

Ron’s WordPress Shortlink https://fishoncomputer.wordpress.com/wp-admin/post.php?post=5851&action=edit

TAXONOMY
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Cetacea
Family: Balaenopteridae

Genus/species: Balaenoptera musculus

GENERAL CHARACTERISTICS: The Blue whale is the largest animal to have ever lived, (almost as big as a Boeing 737. They are actually grayish-blue, with a mottled effect that is visible in some lights and can allow individuals to be identified. 50 people could stand on the tongue, which alone weighs as much as an elephant. The heart of the blue whale is the size of a small car (Volkswagen Beetle).
Blubber can be up to 51 cm (20 inches) thick. The spout of a blue whale can be 9 m (30 ft) high.
Weigh to 203,210 kg or 200 tons (448,000 pounds), as much
as 40 elephants.
Length to nearly 110 feet (33 m (110 ft)

Blue Whale18204939131_ab0b4836d7_k

DISTRIBUTION/HABITAT: B. musculus inhabit the open ocean, where they ares found in every ocean except the Arctic, with a range that extends from the periphery of drift-ice in polar seas to the tropics, although it is absent from some seas such as the Mediterranean, Okhotsk and Bering Sea.

They inhabit the open ocean, where it is found most frequently along the continental shelf edge and near polar ice. It feeds at both the surface and to depths of at least 100 m (300 feet).

DIET: Feeds mainly on shrimp-like krill, which are filtered through the baleen plates. Large volumes of water and food can be taken into the mouth because the pleated grooves in the throat expand. As the mouth closes, water is expelled through the baleen plates, which trap the food on the inside to be swallowed. During the summer months, one blue whale can eat more than 4,082 kg (9,000 lbs) of krill every day (up to 40 million krill a day).

REPRODUCTION: Reaches sexual maturity at 7 to 10 years of age, A calf is produced after 10 to 11 months of gestation which is 7 m (23 ft) long and weighs about 27,215 kg (30 tons or 60,000 pounds) and consumes around 190 liters (50 gallons) of the mother’s fat rich-milk resulting in a daily weight gain of about 90 kg (200 pounds).
Weaning occurs at the summer feeding grounds at about seven months old.

B. musculus produces louder calls than any other animal on earth. It appears to have functions in sensing the environment, prey detection and communication with male display.

CONSERVATION: IUCN Red List Endangered (EN).
No Blue whales have been deliberately caught since 1978. Today, there are an estimated 10,000 to 25,000 Blue whales surviving worldwide, which represents around 2 to 11 percent of the total pre-commercial exploitation population.

California Blue whale numbers are rising, and are possibly close to carrying capacity, according to a new study in Marine Mammal Science. The B. musculus whale population is estimated at about 2,200, or 97 percent of the estimated historical level. t’s a conservation success story. (Approximately 3,400 California Blue whales were caught between 1905 and 1971.)

Primary threats
1. vessel strikes
2. fisheries interactions

Additional threats
1. anthropogenic noise
2. habitat degradation
3. pollution
4. vessel disturbance
5. long-term changes in climate

REMARKS: They can dive 150 m (500 ft) below the surface and remain underwater for 30 minutes.

The Blue whale produces louder calls than any other animal on earth. It appears to have functions in sensing the environment, prey detection and communication with male display.

The California Academy’s Blue whale is an 26.5 m (87-ft) long male that weighed about 80 tons with a 6 m (20-ft) long skull. It was captured for its oil off the coast of Vancouver Island in 1908. It gave 60 barrels of oil and 181 kg (400 lbs) of baleen, the latter used for corsets, buggy whips, and other light-weight yet durable products. The Academy acquired the bones in 1915, and they were buried in the Shakespeare Garden in Golden Gate Park until they were ready for mounting, which was completed in 1917 in an open shed.

References

West Coast Blue Whales journals.plos.org/plosone/article?id=10.1371/journal.pone…

California Academy of Sciences www.calacademy.org/explore-science/blue-whale-survival

California Academy of Sciences  www.calacademy.org/explore-science/blue-whale-population-…

IUCN Red List (March, 2011)  www.iucnredlist.org

NOAA Fisheries Office of Protected Resources – Blue whale www.fisheries.noaa.gov/pr/species/mammals/whales/blue-wha…

ARKive www.arkive.org/blue-whale/balaenoptera-musculus/

Shirihai, H & Jarrett (2006) Whales Dolphins and Other Marine Mammals of the World Princeton University Press.

Evans, P & Weinrich, M (2002) Whales Dolphins and Porpoises D K London New York Munich Melbourne and Delhi.

Reeves, R, R, et al (2002) Guide to Marine Mammals of the World   Chanticleer Press, Inc.

Ron’s WordPress Shortlink https://fishoncomputer.wordpress.com/wp-admin/post.php?post=5843&action=edit

 

 

TAXONOMY
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Subclass: Eutheria
Order: Cetartiodactyla (whales and even-toed ungulates)
Family: Balaenopteridae

Genus/species: Megaptera novaeangliae

Humpback whale

 A group of Humpback whales will locate a large group of small fishes and then blow bubbles from their blowholes as they circle toward the surface. The ring of bubbles forms a “bubble-net” which the fishes and or krill perceive as solid.  The fishes are compressed and the multiple whales then rise in unison to the surface inside the “bubble net” with their mouths open and their pleats expanded for a maxium catch of herring, caplin or sandlance.

All together now coming up

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Big gulp

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The water is expelled through their comb-like baleen (made of keratin) while their tongue sweeps the fishes down their throat.

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Waving good-bye with their flukes elevated and preparing a new bubble-net.

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Note: Flippering:  When a Humpback raises one or both flippers out of the water and slaps them against the water (see above).

Kickfeeding: The Humpback raises and slams his rear flukes against the water surface to stun fishes and then dives and surfaces to engulf the stunned fishes.

REMARKS Individual Humpbacks may lunge into schools of fishes or krill under water.

References

WordPress link:    https://fishoncomputer.wordpress.com/wp-admin/post.php?post=5820&action=edit

Ron’s flickr www.flickr.com/photos/cas_docents/17227254903/in/album-72…

Oxford Journals Integrative & Comparative Biology icb.oxfordjournals.org/content/51/1/203.full

IUCN red list 2008  www.iucnredlist.org/details/13006/0

IUCN Red List (July, 2009) www.iucnredlist.org

Monterey bay aquarium  www.montereybayaquarium.org/animal-guide/marine-mammals/h…

National Geographic animals.nationalgeographic.com/animals/mammals/humpback-w…

ARKive  www.arkive.org/humpback-whale/megaptera-novaeangliae/vide…

Shirihai, H & Jarrett (2006) Whales Dolphins and Other Marine Mammals of the World Princeton University Press.

Evans, P & Weinrich, M (2002) Whales Dolphins and Porpoises D K London New York Munich Melbourne and Delhi.

Reeves, R, R, et al (2002) Guide to Marine Mammals of the World   Chanticleer Press, Inc.

Buffington K, et al (1992) Whales Scholastic Professional Books

 

 

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