Cetacean Taxonomy, Echolocation, and Deep Dives

Cetacean features

telescopes skull, no neck, no external ears, residual hind limbs, cervical vertebrae fused, long-lived, large brain, good direction hearing and sight

Echolocation

use of high-frequency sound to find prey; bounces sound off things and interpret the sound that bounces back

What sound does echolocation utilize?

uses clicks by opening and closing the phonic lips

Physical mechanisms of echolocation?

generates clicks by opening and shutting the phonic lips, vibrations picked up by fatty bursae, vibrations directed by the melon

Time for a click to return equals what?

distance and speed of object

Amount of returning sound equals what?

size of object

Quality of returning sound equals what?

density of object

Superfamily Odontoceti

large conical teeth, predatory, echolocate, often in groups

Family Monodontidae

arctic and nearby seas, no dorsal, high globose forehead, short round pecs, cervical vertebrae not fused, blunt snout no beak

Family Phocoenidae

relatively small, blunt rostrum, stocky body, spade-shaped teeth, triangular dorsal

Family Delphinidae

falciform (sickle-shaped) dorsal, mostly beaky and slender, dorsal in middle of back

Subfamily Globicephalinae

Subfamily of Delphinidae that contains orcas

Subfamily Delphinae

Subfamily of Delphinidae that contains true dolphins

Family Physeteridae

broad flat rostrum, spermaceti organ, blow hole on left side, short throat grooves, teeth only in lower jaw

Solutions to lack of oxygen in deep dives?

small lungs and dive responses (stops breathing when submerged, bradycardia, and peripheral vasoconstriction), high blood volume, extra venous system (rete mirabila), reduced blood flow to non-essential areas, high myoglobin, decreased metabolism

How to prevent the bends?

reduce blood volume, exhale before diving, collapse lungs, dive with full lungs

Superfamily Mysticeti

tongue presses water through a baleen sieve, feeds only in northern feeding grounds, moves to warmer waters to breed, migrate long distances, no echolocation

Family Eschrichtiidae

2-3 throat grooves, short baleen, the only bottom-feeding whale, prefer shallow waters, use vocal cues to communicate

Family Balaenidae

no dorsal, callosities (thick raised tissue on right whales), no throat grooves, skims surface to feed, large heads

Family Balaenoptoeridae

long bodies, smaller heads, flat broad rostrum, shorter baleen, long tapered pecs

Superfamily and Family?

Odontoceti, Monodontidae

Superfamily and Family?

Odontoceti, Monodontidae

Superfamily and Family?

Odontoceti, Phoceoenidae

Superfamily and Family?

Odontoceti, Phoceoenidae

Superfamily and Family?

Odontoceti, Delphinidae, Globicephalinae

Superfamily and Family?

Odontoceti, Delphinidae, Globicephalinae

Superfamily and Family?

Odontoceti, Delphinidae, Delphinae

Superfamily and Family?

Odontoceti, Physeteridae

Superfamily and Family?

Mysticeti, Eschrichtiidae

Superfamily and Family?

Mysticeti, Balaenidae

Superfamily and Family?

Mysticeti, Balaenidae

Superfamily and Family?

Mysticeti, Balaenopteridae

Superfamily and Family?

Mysticeti, Balaenopteridae