Stomphia didemon STODID-092694-SHIRON-005

This entry was posted on Monday, September 26th, 1994 and is filed under Anemones, Spawning Reports.

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: STODID-092694-SHIRON-005

Date received: 9/26/94

Identification: Stomphia didemon (?)

Geographic origin: Pacific Northwest 


Taxonomy: (after I.C.Z.N.)

Kingdom Animalia

Phylum Cnidaria

Class Anthozoa Subclass Hexacorallia (=Zoantharia)

Order Actiniaria Suborder Thenaria

Family Actinostolidae

Genus Stomphia

Species didemon


Description: Information about this sea anemone is scant. Medusa are absent in the life cycle. Solitary or clonal. Septa are paired. Stomphia is characterized by its ability to detach from the substrate and “swim” away by rapidly flexing or bending the column or by thrashing tentacles. This is a temporary behavior is an means of escape form the approach of or contact with a predator. Members of the genus Actinostola and Tealia also exhibit this behavior. 


Duration male(yr): 2+

Size male (mm): 100

Duration female (yr): 2+

Size female (mm): 100

Broodstock notes: Origin undetermined. Had been previously maintained for 5 years in captivity.

Physical differences: None visible. Age and sizes at sexual maturity unknown

Adult diet: Whole shrimp (Crangon sp. ) and fish (Artedius sp.). Irregular feedings 2 – 3 times per month.

Pre-spawning activity: none observed

Time spawning began: morning ~0700

Area spawning occurred: broadcast spawners

Frequency of spawning: annually

Egg description: gametes released freely into tank

Approximate quantity: 1000 – 10000

Size: 0.75 – 0.85 mm

Egg changes / development: totally lecithotrophic

Incubation period: not indicated

Size of hatching larvae: see below

Newly hatched appearance: Oblate spheroid to football shape forms 4 – 5 days at 50F, ~1 mm long by 0.6 – 0.8 mm in diameter.

Transfer / removal method: siphoned out and maintained in beakers until settlement.  


Spawning tank size (liter): 500

Sides of tank covered? No

Lighting & photo period: ambient

Filtration: open system, natural seawater

Additives and dosages: none indicated

Water temperature (F): 50 – 54

Specific gravity: NSW


Planula development / changes: Planula settle on glass/ beaker and attach. Shape becomes lenticular with “lumps”. Dimple develops in top-center and opens as a mouth in 3 – 5 days post settlement. Lumps becme septa.

First food offered: Larvae do not feed

Survival(%): 100% of those which settled

Development description: Tentacles form between septa at 4 – 5 weeks. Others have observed faster development when settlement is in sand.


Rearing tank size (liter): 250

Sides of tank covered? No

Lighting & photo period: ambient

Filtration: open system, NSW

Additives and dosages: none indicated

Water temperature (F): 52 – 54

Specific gravity: NSW


Original description: no information is presently available

Word origin: The genus Stomphia appears to be from the Greek root(s) stom meaning a mouth; and phial meaning a saucer. The origin of the genus didemon is less clear; di has multiple meanings (Greek); two, double, separate, apart; demon could be a form of the Latin word demono meaning an evil spirt (demon).

Vernacular name: Swimming anemone

Suggested reading:

Brusca, Richard C. & Gary J., Invertebrates, 1990, Sinauer Associates, Inc., Sunderland, MA
01375, USA, ISBN 0-87893-098-1

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

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