The Breeder’s Registry© Information contained in this report is taken from submitted observations from aquarist unless noted otherwise (see comments). Information may be reproduced providing the Breeder’s Registry is cited.

Breeder ID: STRHYB-092494-SHIRON-001

Date received: 9/24/94

Identification: Strongylocentrotus hybrid droebachiensis (Müller, 1776) x pallidus (Sars, 1871)

Geographic origin: North Puget Sound, Eastern Pacific 

Taxonomy: (after I.C.Z.N.)

Kingdom Animalia

Phylum Echinodermata Subphylum Echinozoa

Class Echinoidea Subclass Euechinoidea (formerly Centrechinoida) Superorder Echinacea

Order Echinoida

Family Strongylocentrotidae

Genus Strongylocentrotus

Species droebachiensis (Müller, 1776) x pallidus (Sars, 1871) 

Description: Strongylocentrotus droebachiensis is a common urchin with circumpolar range (Ricketts, 1939) being found on the western North American coast from Pudget Sound north. It is also found on the Maine seacoast (Larsen, et al., 1980) with a range of New Jersey to the Arctic (Johnson & Snook, 1927) . They are generally found in shallow waters (30 meters or less) and may be green, whitish or pinkish in color. Test is often violet and up to 5 cm. Spines are moderate length, pointed radiating. S. pallidus is a lesser known species whose range slightly overlaps that of S. droebachiensis. They are a deeper water species found at depths of 20 meters or deeper. They are typically pure white in coloration. Strongylocentrotus sp., are preyed upon by the starfish Pycnopodia (Sunflower star).  

Duration male(yr): 2+ S. pallidus

Size male (mm): 60

Duration female (yr): 2+ S. droebachiensis

Size female (mm): 60

Broodstock notes: Data may apply to both species as they are very similar and may still be speciating. Collected at depths of 18 – 30 meters

Physical differences: none observed

Adult diet: Algae, various types. Continuous grazers

Pre-spawning activity: gametes obtained by injecting 2 – 3 ml of 4.25% KCl through peristomial membrane. Animals spawn about 3 – 5 minutes later after injection @ 46 – 50 F

Time spawning began: as needed

Area spawning occurred: collected in beakers

Frequency of spawning: once per year

Egg description: Eggs are yellow cream color. Sperm is white

Approximate quantity: 20,000+

Size: 100 – 150 m

Egg changes / development: gametes are mixed in beaker. Fertile membrane in 2 – 4 minutes. Blastula @ 20 hours. Gastrula @ 43 hours. Feeding plutens at ~ 90 hours

Incubation period: not stated

Size of hatching larvae: 250 m long

Transfer / removal method: rinsed through 100 m filter 

Spawning tank size (liter): not applicable. Mature adults induced spawning in beakers

Lighting & photo period: unimportant

Filtration: open system, 500 l/ hr

Additives and dosages: none

Water temperature (F): 54

Specific gravity: 1.025

Larval development / changes: 6 arm development @ 212 hours; 470 um @ 264 hours; Juvenile rudiments @ 380 hours; Epaulettes and 7 – 8 arms @ 454 hours; 912 um @ 596 hours; Juvenile feet @ 764 hours.

First food offered: Duneliella , daily additions with water changes

Second food offered: Start grazing ~ 1 week after metamorphosis

Survival

1st week(%): 100

2nd week: 50

3rd week: 10

4th week: 10

Development description: Metamorphosis @ ~ 41 days. Tube feet emerge from pluteus and grasp bottom. Can be raised in high densities ( 2000 – 3000 / liter)  

Rearing tank size (liter): 250

Lighting & photo period: ambient with good diatom growth

Filtration: open system

Additives and dosages: none

Water temperature (F): 54

Specific gravity: 1.025

Comments: Survival is good. 2 cm @ 1 year. 6 cm @ 2 year. Adults live to 20+ years. Do well under a wide range of conditions but require “full strength” seawater for full development.

Vernacular name: Strongylocentrotus droebachiensis green urchin, S. pallidus white urchin, pale urchin

Original description: O. F. Müller first described Strongylocentrotus droebachiensis in 1776. S. pallidus was described by G. O. Sars in 1871. No other information presently available.

Word origin: The genus Strongylocentrotus is from the Greek root(s) strongylo meaning round; and centro meaning the center, a point, spear or spine. The species droebachiensis is in honor of the Norwegian fjord of Dröbak indicated by the suffix ensis. The species pallidus is from the
Latin root pallid meaning pale.

Suggested reading:

Himmelman, J. H., Reproductive cycle of the green sea urchin Strongylocentrotus
droebachiensis. 1978, Canadian Journal of Zoology, 56:1828 – 36

Johnson, Myrtle E. & Harry J. Snook, Seashore Animals of the Pacific Coast, 1967, Dover
Publications, Inc., 180 Varick Street, New York, NY 10014, USA (reprint of 1927 work
published by MacMillan Company) ISBN 486-21819-8

Larsen, B. R., Vadas, R. L., and Keser, M., Feeding and nutritional ecology of the sea
urchinStrongylocentrotus droebachiensis in Maine., 1980, Marine Biology, 39: 25-30

Ricketts, Edward F., Calvin, J., Hedgpeth, J. W., Between Pacific Tides, Fifth Edition, Revised
by David W. Phillips, 1985 (Previous editions; 1939, 1948, 1952, 1968) Stanford University
Press, Stanford, California, USA. ISBN 0-8047-1229-8

Stearns, Louis W., Sea Urchin Development: Cellular and Molecular Aspects, 1978, Dowden,
Hutchinson & Ross, Inc., 523 Sarah Street, Stroudsburg, PA 18360 USA. ISBN 0-87933-026-0

About this report: Information contained in this report is taken from submitted observations. Taxonomy, Synonomy, Original description , Word origin and Suggested reading are provided by member(s) of The Breeder’s Registry staff. Information is presented under the belief that it is accurate. If you have information in addition to, or contrary to that presented you are encouraged to contact the Breeder’s Registry. Permission is granted for “one-time” personal use. Reproduction as distributed or accessible media is prohibited without prior written permission. All rights reserved. 1994