Report: Premnas biaculeatus (Rcvd: 1/10/98)

© 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: PREBIA-011098-BURJAN-003

Date received: 1/10/98

Identification: Premnas biaculeatus (Bloch, 1790)

Geographic origin: Indo-Pacific

Taxonomy:

(after I.C.Z.N.)

Kingdom: Animalia

Phylum: Chordata

Subphylum: Vertebrata

Class: Osteichthyes

Order: Perciformes

Superorder: Teleostei

Family: Pomacentridae

Genus: Premnas

Species: biaculeatus (Bloch, 1790)

Description:

Bright red to brownish red body with three bars, generally narrow, but varies. Bars
are typically while with a thin dark border. Bars are yellowish in some species (Sumatra region) .
Spines just below the eye are easily seen; Females much larger (to 160 mm). Males are typically
much smaller (60 – 80 mm) and often brighter. Stripes disappear from the underside up as the
fish become older. Some specimens in captivity have become almost completely solid colored.
Distinct from all other anemonefishes.

Duration male(yr): 4

Size male (mm): 63

Duration female (yr): 5

Size female (mm): 113

Broodstock notes: None.

Physical differences: The female is larger, darker of color and much heavier of body.

Adult diet: Mash of fish, scallops, clams, mussels – whatever looks freshest at the fish market; with added spirulina, Vita-chem vitamins, Vit C and Selcon.

Pre-spawning activity: Several weeks of nest cleaning prior to 1^st spawn. Female is extremely aggressive to male and in defending her territory.

Time spawning began: Late afternoon

Area spawning occurred: Inside a broken pot at the base of their anemone (Entacmea quadricolor).

Frequency of spawning: Every 2 weeks plus or minus a day.

Egg description: 2″ diameter circle of pale orange eggs.

Approximate quantity: Not indicated.

Size: ~ 2 mm

Egg changes / development: The eggs darken to grey then develop bright silvery eyes.

Incubation period: 7-8 days

Time hatching occurred: 45 minutes after lights go out

Size of hatching larvae: ~ 4 mm

Yolk sac present?: Yes, small.

Newly hatched appearance: Not indicated

Transfer / removal method: Not indicated.

Spawning tank size (liter): 225 (3 tanks connected with filter)

Sides of tank covered? No

Lighting & photo period: Type not indicated, (13 hours).

Filtration: Central – Live rock, live sand, Sea Storm, Phos-guard, mid-size CPR protein skimmer.

Additives and dosages: None.

Water temperature (F): 74° F

Specific gravity: 1.022

pH: 8.2

Nitrate: 20 ppm

Fry development / changes: Not indicated.

First food offered: Rotifers, live fed on Isochrysis.

Second food offered: Not indicated.

Survival

4th week: Low

Development description: 1-3 survivors per batch.

Rearing tank size (liter): 75

Sides of tank covered? Yes, black

Lighting & photo period: Type not indicated, (13 hours).

Filtration: Central system (as above).

Additives and dosages: None.

Water temperature (F): 74° F

Specific gravity: 1.022

pH: 8.0

Nitrate: 20 ppm

Notes:

I have not had much success with babies living, probably due to water quality. The water I use is well water with a large amount of calcium carbonate and not much else. The alkalinity of my system is very high – so much so that I have to add acid to get the algae and rotifers to grow. At the same time my calcium seems to be low and nitrates still too high. My water source is a well containing large amounts of calcium carbonate. This seems like it should be a help to the system but my alkalinity has gone way up to 5-6 meq/L and my calcium level has dropped very low to 283 mg/L. I don’t use other supplements. Last summer, after several years of successfully raising rotifers my culture crashed and I could not get a new one started.

I pulled all my references and re-read everything. There was a brief mention of the pH being too high. With addition of small amounts of acetic acid I was successfully raising algae and rotifers again.

Comments: Gerald Allen recognized Premnas and Amphiprion as subgenera of Amphiprionin
Allen , G. R. 1972. The anemonefishes: their classification and biology. T. F. H. Publications,
Neptune City, 288 pp. (Specifically on pages 4- -45). Stephen Spotte follows this description
giving preference to genus Amphiprion in Spotte, S. 1992. Captive seawater fishes: science and
technology. Wiley-Interscience Publication, New York, 942 pp. (Specifically on pg 716).
However, Allen is acknowledged as validating Premnas biaculeatus in 1991.

This species has been previously listed under the following names: Chaetodon biaculeatus
(Bloch, 1790), Lutjanos trifasciatus (Schneider in Bloch & Schneider, 1801), Scorpaena
aculeata, Holocentrus sonnerat (Lacepede, 1802), Holocanthus biaculeatus, Premnas
trifasciatus( Cuvier in Cuvier & Valenciennes, 1830), P. leucodesmus (Cuvier (ex Kuhl & van
Hasslet)), P. semicinctus ( Cuvier in Cuvier & Valenciennes, 1830) , P. unicolor (Cuvier, 1829),
Sargus ensifer (Gronow in Gray 1854), and Premnas epigrammata (Fowler, 1904).

Word origin: Premnas; very few Greek or Latin roots end with an “s” following an “a”and the
actual meaning of this word could be “based” in another language. The Greek word premn, -o,
=um, means stem or a tree trunk. It could be based on the Latin root pre, meaning before,
however, the closest derivation of -mnas is mnen, -at, -on which is Greek for memory or
remember. The species provides almost equal mystery; biaculeatus; bi being Latin for two,
twice or double; and acule, =us, being Latin for a sting, or horn. The ending is again
uncommon, however the two known roots indicate “two horns” which would seem appropriate
since this species has one or two well developed spines below the eye (Axelrod, et al., 1969) and
the common name of Spine-cheeked Anemone or clownfish.

Suggested reading:

Fautine, Daphne G., & Allen, Gerald R., Anemonefishes and their Host
Anemones 1994, Tetra Press, Germany, 158 pages, ISBN 1-56465-118-5

Tullock, John H., Clownfishes and Sea Anemones, 1998, Barron’s Educational Series, 250 Wireless Blvd., Hauppauge, NY 11788. http://www.barronseduc.com, ISBN 0-7641-0511-6 (softbound)

Wilkerson, Joyce D., Clownfishes: A Guide to Their Captive Care, Breeding
& Natural History 1998, Microcosm, Shelburne, Vermont 05482 USA, 240 pages , ISBN 1-890087-04-1 (softbound)

About this report: Information contained in this report is taken from submitted observations.
Taxonomy, Description, 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. 1998