Hexanchidae
sixgill shark
Hexanchus vitulus
FISH SPECIES
Sharks
Sharks are cartilaginous fishes with skeletons made primarily of cartilage. They include small bottom dwellers, open-ocean hunters and giant filter feeders such as the whale shark.
FISH ATLAS / FIELD GUIDESharksIN THIS CHAPTER01 / Characteristics02 / Lifestyle03 / Species04 / Field notes
SCROLL
01 / NATURAL HISTORY
Characteristics
Typical features include exposed gill slits, replaceable teeth and placoid scales that give the skin a tooth-like texture. Body form and feeding strategy vary across the major shark orders.
- 01Ground sharks
- 02Mackerel sharks
- 03Carpet sharks
02 / LIFESTYLE
Lifestyle
Shark locomotion and foraging strategies reflect adaptations across diverse marine niches. While active pelagic predators utilize obligate ram ventilation and cruise continuously using specialized caudal keels, many benthic species possess spiracles that allow stationary pumping while resting on the ocean floor. Electroreceptive ampullae of Lorenzini detect minuscule bioelectric fields emitted by buried prey during low-speed sweeps.
OBSERVATION INDEX
- Continuous cruising vs stationary rest
- Bioelectric tracking with ampullae
- Pelagic schooling and bottom hunting
03 / SPECIES
Representative species
Discover representative species illustrating the ecological diversity, morphologies and adaptations of this group.
sixgill shark
Scyliorhinidae
Slender catshark
Schroederichthys tenuis
Pentanchidae
Slender sawtail catshark
Galeus gracilis
Pseudotriakidae
slender smooth-hound
Gollum attenuatus
Hemigaleidae
Slender weasel shark
Paragaleus longicaudatus
Etmopteridae
Slendertail lanternshark
Etmopterus molleri
Carcharhinidae
sliteye shark
Loxodon macrorhinus
Squatinidae
Small-crested angelshark
Squatina mapama
Pentanchidae
smallbelly catshark
Apristurus indicus
Pentanchidae
smalleye catshark
Apristurus microps
Sphyrnidae
smalleye hammerhead
Sphyrna tudes
Etmopteridae
Smalleye lantern shark
Etmopterus litvinovi
Dalatiidae
smalleye pygmy shark
Squaliolus aliae
Triakidae
Smalleye smooth-hound
Mustelus higmani
Pentanchidae
Smallfin catshark
Apristurus parvipinnis
Centrophoridae
smallfin gulper shark
Centrophorus moluccensis
Carcharhinidae
smalltail shark
Carcharhinus porosus
Squalidae
Smith’s dogfish shark
Squalus margaretsmithae
Triakidae
smooth dogfish
Mustelus canis
Sphyrnidae
Smooth hammerhead
Sphyrna zygaena
Etmopteridae
smooth lanternshark
Etmopterus pusillus
Squatinidae
smoothback angelshark
Squatina oculata
Triakidae
smoothhound
Mustelus mustelus
Carcharhinidae
Smoothtooth blacktip shark
Carcharhinus leiodon
04 / FIELD NOTES
A closer look
Must all sharks swim constantly to avoid suffocating?
No. Only certain open-ocean sharks rely on obligate ram ventilation. Many bottom-dwelling species (like nurse and carpet sharks) use spiracles and buccal pumping to breathe while resting stationary on the ocean floor.
How many teeth do sharks produce in a lifetime?
Shark teeth are arranged in conveyer-belt rows and continually shed as they wear down; an individual shark can produce thousands of functional teeth over its lifetime.
Is a whale shark dangerous to humans?
No. Despite reaching over 12 meters in length, whale sharks are gentle filter feeders that consume microscopic plankton, krill and small schooling fishes, posing no danger to divers.