S E A H O R S E S 1 0 1 With K-Dog

• Taxonomy

• Evolution and Fossil Record

• Distribution

• Anatomy

• Reproduction and pregnancy

• Predators and human threats

• Protection and conservation status

TA XO N O M Y

• 120 species names proposed over last 200 years

• Project Seahorse recognizes 47 species

• Genus: Hippocampus

• Family: Syngnathiformes, related to pipefish

E VO LU T I O N & F O S S I L R E C O R D

• Two pipefish-like fossils found in Slovenia each 13 million years old

• Molecular, physical and genetic evidence shows seahorses are highly modified pipefish

• Molecular dating finds that seahorses and pipefish diverged during Late Oligocene

• Speculation of evolving in response to large new areas of shallow water, created following recent tectonic events

Distribution• Usually live in seagrass beds, mangrove roots, and coral

reefs in shallow, temperate, and tropical waters• Roughly range from 50°N to 50°S latitude• Habitat degradation threatens species as they inhabit

shallow areas that are easily influenced by human activities• Non-migratory: cannot move if home habitat is destroyed

S URV I VA L

• Natural lifespans virtually unknown

• Estimates range from 1 year lifespan for smaller species to 3-5 years for larger species

A N AT O M Y

• Unique features

• Have no scales, thin membrane covering series of bony plates visible as rings around trunk and tail

• Rings, cheek spines and coronet useful in identifying species

• Have no stomach or teeth, instead use tubular snout

• Inefficient digestive system

• Breathe through gills like other fish

• Swim using propulsive force of a quickly oscillating dorsal fin, use pectoral fins on either side of body for maneuverability and stability

• Males can be identified by presence of a brood pouch

S I Z E A N D C O LO R I N G

• Size range varied by species

• Australian big-bellied seahorse (H. abdominalis) can surpass 30cm

• Pygmy seahorse is less than 2cm

• Weight varies by reproductive stage

• Quick, short-term color changes may occur during courtship or daily greetings during pregnancy

• Masters of camouflage

• Can grow bumps on rings or skin filaments to blend in with surroundings

F E E D I N G

• Opportunistic rather than dynamic predators

• Smaller species mainly feed on copepods

• Larger species feed on larger amphipods, caridean shrimp, brine shrimp, and peracarids

REP RODU C T I ON

• Male becomes pregnant

• Sexual maturity determined by presence of a brood pouch

• Monogamous, couples have a daily greeting every morning during pregnancy

• Female inserts ovipositor into male’s brood pouch and releases eggs, male fertilizes, eggs become enveloped with tissues

P R E G N A N CY• Pouch acts like the womb of a

female mammal, complete with placental fluid

• Pouch fluid acts as an osmotic adaption chamber, alters composition to resemble surrounding ocean water

• Pregnancy usually lasts between 2 and 4 weeks depending on the species

• Young are miniature adult seahorses, no parental investment after birth

• Most newborns between 7 and 12 mm in length

• Average number of newborns ranges from 100 to 200

• Can be as low as 5 in smaller species or up to 1,500

P R E DAT O R S

• Less than 1% survival rate in young

• Crabs a common predator in shallow waters

• In certain areas octopus and sting rays have been known to prey on young

• Have been found in the stomachs of invasive lion fish in the Caribbean

• Tuna will eat especially in times of year when regular food sources are in short supply

H U M A N T H R E AT S

• Chinese medicine trade takes about 150 million from wild every year

• Curio trade takes about 1 million a year, taken live and left to die in the sun

• Aquarium trade takes 1 million every year, estimated that less than 1000 live past six weeks

The Curio Trade

PROT E CT I ON & CONSE RVAT I ON

STAT U S

• IUCN Redlist includes 38 species

• 1 species listed as endangered

• 7 species listed as vulnerable

• 1 listed as least concern

• 29 listed as data deficient

• In 2002 seahorses were included in Appendix II of CITES which monitors and limits international trade