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An Introduction to Marine Mammals: With a focus on

India

Mridula Srinivasan, Ph.D. Terra Marine Research Institute

2013 Timi-Kurm Festival

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Roadmap

Marine Mammal BasicsWhy Marine Mammals are UniqueMarine Mammal Types Cetaceans Cetaceans of IndiaStudying Marine Mammals

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Mammals BASICS

Nurse young

Have hair

Warm blooded

Four-chambered heart

Parental Care

Lungs to breathe

Same core body temperature

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Marine Mammal BASICS

Nurse young Have hair Warm blooded Four-chambered heartParental Care Lungs to breatheSame core body temperature

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Gestation period range: 10-17.5 months

1 – 3 year birth intervalbreeding – migration (only whales) –

feeding – calving – lactation – weaning – resting/playing

Marine Mammal Basics Cont.…

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Hippopotamus - Whales & Dolphins

Manatees & Dugongs - ELEPHANTS

Bears - Seals

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Whale Evolution

VIDEO

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What makes marine mammals unique ?

Breath holding (High Myoglobin) Live and reproduce for the most part in water Deep divers May drink salt water, get water from prey Longest migrationsBlubber/fur (insulation)

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Vision

HEARING AND COMMUNICATION (SOUNDS)

Smell• Above and below water

• No eyelashes• More rods then

cones/some color vision

http://cetus.ucsd.edu/voicesinthesea_org/videos/videos.html (VOICES OF THE SEA)

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~78 SPECIES OF WHALES, DOLPHINS, PORPOISES

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4 species (manatees and dugong)

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~33 species of seals, sea lions, walrus

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Sea Otters Polar Bears

Depend on ocean for foodMarine - related to weasels, badgers, river otters

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Kingdom AnimaliaPhylum ChordataClass MammaliaOrder – Cetacea – Whales and DolphinsOrder – Sirenia – Manatees and DugongsOrder – Carnivora – Polar bear, seals, sea lions, otters

Marine Mammals of the World – Classification

                                 

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Whales, Dolphins, and Porpoises (Cetaceans)BalaenidaeNeobalaenidaeEschrichtiidaeBalaenopteridaePhyseteridaeKogiidaePlatanistidaePontoporiidaeLipotidaeIniidaeMonodontidaePhocoenidaeDelphinidaeZiphiidae 

Seals, Sea Lions, and Walrus (Pinnipeds) PhocidaeOtariidaeOdobenidae

Manatees and Dugongs (Sirenia)TrichechidaeDugongidae

Polar Bears and Sea Otters (Carnivores)UrsidaeMustelidae

Taxonomy – Family

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Cetaceans: Whales and Dolphins, and Porpoises

Two Sub-Orders---

Mysticetes (Baleen Whales)

Odontocetes (Toothed Whales)

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Marine Mammals of India

• KNOWN 20-25 species found in India- Ganges River Dolphins- Indo-Pacific Humpback Dolphins- Irrawaddy Dolphins- Dwarf Sperm Whales- Bottlenose dolphins- Dugongs- Beaked whales- Finless Porpoise- Humpback Whales- Sperm Whales

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Baleen whales or Mysticetes

Have 2 blow holesFemales are larger than malesMostly solitary, but cooperate during feeding!Long migrationsUse low frequency sounds (<10KHz)to communicate long distances4 families with a total of 14 species

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Mysticete External Morphology

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Tooth brush or baleen!!

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Baleen size and feeding techniqueGray whale – shortest baleen sediment or bottom feeding. Biggest reason for organic sediment turnover in the oceans.Right and bowhead whales – thickest and longest baleen – skim feedersHumpback and blue whales ( rorqual whales) – intermediate length baleen mid-water column feeding, gulp or lunge feeders

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Know a whale from its blow! Right Whale Blow

Characteristic V- shaped

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Family: Balaenopteridae

• Rorquals (2 genera, 8 species)

• 7 separated cervical vertebrae

• Small dorsal fin behind midline

• 30-100 gular grooves• Short baleen plates, 200+

per side

Blue whale (Balaenoptera musculus

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Toothed Whales or Odontocetes

One blowholeKiller whales sexually dimorphicStrong social bondsKnown for their human/chimp equivalent Cognition and IntelligenceUse echolocation to feed and communicateUse high frequency sounds to communicate 10kHz-100KHz10 families with at least 71 species

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Odontocete External Morphology

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Female (Lagenorhynchus

obscurus)

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Male

(Lagenorhynchus obscurus)

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Family: Physeteridae

• Sperm whale (Physeter macrocephalus): 1 species

• 18-25 conical teeth on lower jaw only• Dorsal hump; no fin

• All cervical vertebrae except first are fused

• Males 15-18 m; females up to 11 m

• Feeds primarily on deep-water squid at depths of up to 600m

Produces ambergris – a valuable substance in perfumes.

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Family: Kogiidae• Pygmy and dwarf sperm

whales (1 genus, 2 species)

• Blunt, shark-like head

• Small, sub-terminal lower jaw• 24-32 conical teeth in lower

jaw• Diet primarily deep-sea

cephalopods and slow moving fish

Breaching Dwarf sperm whale (Kogia simus)

Pygmy sperm whale (Kogia breviceps)

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Family: Ziphiidae

• Beaked whales (6 genera, 20 known species)

• Protruding rostrum with arched jaws

• Small dorsal fin past midline• Cuvier’s beaked whale –

Deepest diving record – 1,800 meters in 45 minutes

• 1-2 pairs of teeth on lower jaw in most species

• Non-notched flukes • Feeds primarily on deep-

sea squid• Also has spermaceti

A rare photograph of Blainville’s beaked whale (Mesoplodon densirostris) Northern Bottlenose whale (Hyperoodon

ampullatus) aboard a whaling ship

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Family: Platanistidae

• Indus (bhulan) & Ganges (susu) river dolphins (1 species)

• Long, narrow beak with no whiskers

• No dorsal fin; low dorsal hump• Small eyes and poor vision

• Broad, paddle-like pectoral fins• 2-3 m in length• Range limited to the Indus and

Ganges river basins.

Two captive Susus (Platanista sp.)

Platanista gangetica India’s National Aquatic Animal

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Family: Delphinidae

• 36 species, 17 genera• Range from 1.5-10 m

in length, 50-9000 kg• Conical, functional

teeth in both jaws• All but genus

Lissodelphis have dorsal finCommon dolphin

(Delphinus delphis)

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Family: Phocoenidae

• The porpoises: 3 genera with 6 species

• Porpoises are distinguished from other Odontocetes by their small body size • The porpoises are an elusive and

relatively poorly known group. They feed on small pelagic and mesopelagic fish and squid. Their lifespans are relatively short (~20 years), and they usually spend their time in small, fluid social groups.

Finless porpoise (Neophocaena phocaenoides)

Harbor porpoise (Phocoena phocoena)

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Dolphin and Porpoise features

spade shaped teeth cone shaped teeth

triangular dorsal fincurved or hooked dorsal fin

no beak often prominent beak

Porpoise Features

Dolphin Features

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What can we hope to see in waters near Karwar and Goa

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What can we learn from studying dolphins and whales and how do we study them?

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Photo Identification

• Identifying unique individuals by markings on their dorsal fin

• Saddle-patches plus dorsal fin for killer whales

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Dorsal Fins

Unusual pigmentation/scars

Trailing edge

Leading Edge

Top chopped

Top Notch

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What can we use this for?• Movement patterns (migrations)• Habitat use and Distributions• Site fidelity• Population estimates and Abundance• Association patterns (social behavior)• Predation & Predator Effects• Behavior – Feeding, Mating, Social, Play• Behavioral Ecology• Environmental and Human Effects• Wildlife Management and Policy• Environmental Regulations

LOCAL, REGIONAL, NATIONAL, GLOBAL SCALES

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Other Techniques • Biopsy• Radio Tracking and

Satellite Tagging• Boat-based studies• Theodolite tracking

(Hill-based)• Unmanned systems• Acoustic tracking –

listening to whales• Aerial and Ship

surveys• Modeling

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WHY SHOULD WE CARE?

They are like “humans”Top of the food chain ‘TIGERS OF THE SEA’Sentinels of Ocean Health and Climate ChangeThey keep ecosystems in check National Aquatic Animal – Ganges River Dolphin

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The End

Thank you!

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Back Up Slides

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WHOI CSI

• http://csi.whoi.edu/interactive/harborporpoise2d (harbor porpoise body)

• http://csi.whoi.edu/interactive/pinnipedskulldorsal2d (pinniped skull)

• http://csi.whoi.edu/interactive/odontoceteskulllateral2d (dolphin skull lateral)