AQUACULTURE: SEA
URCHINS- THE SPINY
HEDGEHOG OF THE
SEA
Marlee Hayes
• Green Sea Urchin
• Strongylocentrotus droebachiensis
• Purple Sea Urchin
• Strongylocentrotus purpuratu
• Red Sea Urchin
• Mesocentrotus franciscanus
• The variegated sea urchin
• Lytechinus variegatus
SPECIES
• Over fishing has negatively
impacted sea urchin populations.
• Aquaculture, especially inland, is
just beginning.
• Sea Urchins have great potential for
sustainable aquaculture.
• High fecundity
• Quick growth rate
• Hardiness
• The consumable part of the Sea
Urchin is the Roe or Uni.
SEA URCHIN
ANATOMY
ECONOMICAL/ECOLOGICAL
IMPORTANCE
• Valuable food item in Japan,
France, United States, China and
other areas.
• California exports a large amount of
sea urchin to Japan.
• Sea Urchins are grazers.
• Possible keystone species.
• Urchins can decimate kelp beds.
• Kelp provides a natural product,
algin.
• Sea otters, sea stars, wolf eels and
triggerfish are predators of urchins
• Model organism for scientific
research
• Market Prices
• Catalina Offshore Products, California, AL
• 1 pound live wild whole red or black sea
urchin $13.99
• California Gold Uni 80 grams $19.99
• California Premium Uni 80 grams $11.99
• Santa Barbra Fish Market
• $9.95 each Fresh caught by divers
• Japan
• Approximately $ 8.20-$40.98 per tray
(imported from California)
• Seasonality
• the price of Chilean fresh roe almost triples
off-season: from around $12 per kilo roe to
around $36 per kilo of roe.
• Diecous Broadcast
Spawners
• External Fertilization
• Seasonal Conditions
• Photoperiod,
• Temperature
• Salinity
• Echinopluteus
Larvae(months) →
Metamorphosis (~30 min) →
Adult (max size ~5years)
LIFE CYCLE
REPRODUCTION IN CAPTIVITY
• Spawning can be induced by
acetylcholine/potassium chloride
injection
• Eggs or sperm can be collected by
placing urchin upside down over
beak and gametes will be released
from the gonodapore
• Sperm needs to be diluted with
saltwater to be activated and
prevent multiple fertilizations
• Temperature changes can also
induce spawning
• https://www.youtube.com/watch?v
=Qf22WvlDUeI
PRODUCTION METHODS
• Offshore sea farming
• Cages where urchins
are raised in open
ocean
• Stock enhancement
• Hatching larvae and
growing until small
juveniles, then release
into wild until harvest
PRODUCTION METHODS
Land based
raceways/Tanks
• Small Scale Successes
• UAB
• Texas A&M
• Gonad enhancement
• Seasonality issue remedied
SEA URCHIN PLATTER SYSTEM
• Ireland UCC
• Stackable,
layered
FEEDING
• Macroalage (Larvae need single celled algae)
• Juveniles (phytoplankton/diatoms)
• Seaweed (Kelp)
• High-protein, sinking, pelleted food
• No commercially-available feed for large scale
• Standardized optimal feed is needed
FEEDING
• Research to produce ideal
feed to meet nutrition
requirements and produce
the best marketable
product
• Enhancement of Gonad
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Size
Color
Texture
Taste
FEEDING
http://www.travelchannel.com/video/tastytest-tube-sea-urchins
WATER CHEMISTRY AND
ENVIRONMENTAL CONDITIONS
• Temperature 20 -26° Celsius
• Synthetic Sea Water
• Salinity 35 mg/L
• Recirculating System with mechanical, chemical, and biological filters, UV
sterilization and aeration
• Feces must be manually siphoned
• pH of 7.5
• Partial water change 1-3 times weekly
• Oxygen Levels and Light Cycles can affect growth and development
ADVANTAGES
• High Fecundity
• Hardy
• Can be cultured densely
• Rapid growth rate
• Gonad development can be
enhanced
• Year round production
• Potential for poly culture
• Protection from predation
• Standardized feed
• Can’t see the product
DISADVANTAGES
• Land based Tanks/Raceways
• Mass spawning event
• Larval care/stages
• Intensive
• Manually siphon system (dense feces)
• Eat anything including equipment
• Sea based Cages/Ranches
• Environmental Impacts
• Unpredictable
• Pollution
• Nutrification
• Physical Damage
• Burying/ Crushing
SEA URCHINS ARE COOL!
• Certain species of sea urchins (such as flower urchin) have spikes filled with venom.
The flower urchin is extremely venomous and has caused rare
fatalities. Toxopneustes pileolus
• Sea urchin has special type of mouth, called "Aristotle's lantern". Mouth is equipped
with five sharp teeth that are able to drill a hole in the rock. Using its Aristotle’s
lantern, the purple sea urchin is capable of biting pieces out of the rock, and the
spines slowly erode away at the surface, creating a small pit in which the urchin may
remain for long periods of time.
• Red sea urchin may have the longest lifespan on Earth. It can potential survive up to
200 years in the wild. In other words, an individual red sea urchin that hatched on
the day in 1805 that Lewis and Clark arrived in Oregon may still be thriving – and
even breeding.
• https://www.youtube.com/watch?v=hD4zfopXAHY
ACKNOWLEDGEMENTS
Dr. Stephen Watts
Dr. Hugh Hammer
Dr. Mickie Powell
Laura Heflin
Watt’s Lab
SRAC
FAO
Sea Urchins: Biology
and Ecology by
John M Lawrence
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