Rosalie Flores Marine Aquaculture

Echinoderm (echino=spiny, derms = skins) Paracentrotus lividus – European Strongylocentrotus droebachiensis (green sea urchin) – Japan Evechinus chloroticus (kina) – New Zeland

Sea urchins are important for roe harvesting. Their roe (gonads) are a seasonal product and only acceptable to the market during a window of a few months ( before spawning period of urchins specific to that region). In the U.S. and Japan they are retailed for about $6 for two tongues or $35 to $40/ lb. In Japan – “uni” is sushi containing roe (delicacy)

Pluteus Larva stage - gut, mouth and skeleton formed. Larva drifts in water column for 3wks-3mos, eating until they are big enough to settle on seabed & undergo metamorphosis (after finding a spot close to food that’s far from predators). Larva takes on adult form in less than 30 mins (mini me) Continues to eat algae/kelp to grow from juvenile to mature adult capable of reproduction (depending on species & nutrient availability) is ~ 3-5 yrs

(Australia)

Spawning induced by injections of acetylcholine, potassium chloride or by electrical stimulation (placed in larvae tank to grow) Cold to warm – induces spawning (spring) Male & female have 5 gonadal “tongues” that contain nutritive cells with either eggs or sperm Juveniles harvested from wild – achieve significantly increased roe (in aquaculture conditions) in just 12 weeks (not 20 mos in field conditions)

Farming Strategies considered for grow-out include sea-based cage systems, sea ranching, and land-based tank systems. Roe enhancement – juveniles caught from wild & allow growth for 12 weeks (in aquaculture conditions)

Stock enhancement – hatching out larvae in the hatchery and growing to small juveniles, then releasing in wild. Placing small juveniles into cages along coastal waters (good water flow, no f.w. output, seaweed, and protection) to allow growth (500/cage)

Sea urchins eat seagrass, algae, kelp, and other greens Brown algae accounts for 64% of the field diets and green algae, 24%. Oven dried powder pellets can be used - composed of carbohydrates and protein.

Salt water ( can’t survive in freshwater) pH 7.6 – C

Can adapt and survive in high density conditions ( kg/m2) Protection from predators via sharp spines Slow moving Reproduce in great numbers

UNI !!!!! F7F9Yv8k8&feature=related