12 Glossary

12. Glossary

Term	Definition
Ambulacral Plates	Part of the urchin test with tiny holes through which the tube feet extend
Ambulacral Ridges	Ridges on the test of sea urchins where the tube feet are located
Ampullae	Structures at the base of the tube feet that contract to hydraulically move the tube feet Part of the hydrovascular system
Aristotle’s Lantern	Complex mouth structure in sea urchins
Anal/aboral side	The top part of the urchin opposite the mouth
“Barren” or “Empty” Urchins	Urchins with little to no gonad (GSI <1-5%)
Biofouling	The accumulation of microorganisms, plants, algae, or animals on wetted surfaces, which can affect system performance
Biosecurity	Measures to prevent the spread of certain species in aquaculture
Broadcast Spawning	Method of reproduction where sperm and eggs are released into the water
Carotenoids	Organic pigments found in plants and algae which influence color in sea urchin gonads
Coelomic Fluid	The fluid in the body cavity of sea urchins
Desiccation	The process of aquatic organisms drying out
Echinoderms	A group of marine animals including sea stars, sea urchins, and sea cucumbers Meaning “Spiny Skin”
Epidermis	Thin layer of skin on the exterior of sea urchins which deposits new test and spine material
Fecal Pellets	Urchin feces, which are typically compressed by their digestive system into small pellets
FLUPSY	Floating Upweller System A floating system for growing shellfish or other marine organisms in flowing water
Flow Dynamics	How water moves and is distributed within a system
Flow Rate	The rate at which water is supplied to a system, usually measured in gallons per minute (GPM)
Gametes	Sperm or eggs
Gametogenesis	The process of developing sperm and eggs from nutrient reserves stored in the nutritive phagocytes
Genital Pore	The pore on the anal side of the urchin through which gametes are released during spawning
Germinal Cells (GCs)	Cells in sea urchin gonads responsible for creating gametes
Gonad	Reproductive structure that produces gametes
Gonad Somatic Index (GSI)	Index used to measure the reproductive condition of sea urchins GSI % = 100* Gonad Weight/Whole Weight
Growth Phase	Part of the urchin reproductive cycle when gonads develop nutrient reserves stored in the nutritative phagocytes
Hydrovascular System	A system in echinoderms that uses seawater to create hydraulic pressure for movement and other functions
Kelp Holdfast	The base of a kelp organism which anchors it to the seafloor
Intertidal Zone	The area of the coast which is alternatively covered by the ocean and exposed to air based on the shifting of the tides
Macroalgae	Multicellular algae species
Madreporite	Opening in sea urchins supplying seawater to the hydrovascular system
Maturation Phase	Part of the urchin reproductive cycle when gametogenesis and spawning occurs
Milt/Oozing/Spawny/Spawniness	Liquid gametes visibly leaking out of gonads
Moribund	A state in which an organism is dying or near death
Nutritive Phagocytes (NPs)	Cells in sea urchin gonads that store nutrients
Oral side	The side of the urchin which contains the mouth
Palatability	The attractiveness and acceptance of feed by sea urchins
Pentaradial Symmetry	A circular, symmetrical body plan divided into 5 repeating sections
Peristomal Area	Area surrounding the mouth of a sea urchin which is prone to damage
Photoperiod	The day-length an organism is exposed to, affecting its reproductive cycle
Roe Enhancement	Enhancing the quality or quantity of sea urchin roe (uni)
Spawning	The release of sperm and/or eggs into the water
Spent/Regeneration Phase	The phase of urchin reproduction after spawning when unreleased gametes are reabsorbed and gonad growth is minimal but begins to occur
Subtidal Zone	The area of the ocean which extends from the low tide mark and is always underwater
Survivorship	The number of urchins that survived as a percentage of the original population
Test	Large flattened spherical shell of sea urchins, made of calcium carbonate plates
Tube Feet	Array of tentacles in echinoderms used for locomotion, oxygen exchange, and other roles
Urchin Barrens	Areas where overpopulated sea urchins have greatly reduced kelp, leading to barren seafloors
UV Sterilization	Use of ultraviolet light to kill or inactivate microorganisms in water