Pempheris schomburgkii PEMSCH-020799-BROJEN-001

This entry was posted on Sunday, February 7th, 1999 and is filed under Spawning Reports, Sweepers.

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: PEMSCH-020799-BROJEN-001

Date received: 2/7/99

Identification: Pempheris schomburgkii (Müller & Troschel, 1848)

Geographic origin: Florida Keys


Taxonomy: (after I.C.Z.N.)

Kingdom Animalia

Phylum Chordata Subphylum Vertebrata

Class Actinopterygii ( = Osteichthyes)

Order Perciformes Suborder Percoidei

Family Pempheridae

Genus Pempheris Cuvier 1829

Species shomburgkii Müller & Troschel, 1848


Description: Pempheridae is a small family with seven (7) genera (Catalog of Fishes, 1998, California Acadamy of Science). The body is compressed, deep bodied anteriorly and tapering quickly toward the tail with a long anal fin. The eyes are large. Coloration is coppery with a dark band at the base of the anal fin. Young are nearly transparent and are silvery over the abdomen (hence the common name “Glassy”). Found in large schools in caves during the day. Feed at night on zooplankton, especially larger stages of larval invertebrates.


Meristic characteristics : DR V, 8 or 9; AR III, 32 to 35; PR 17 or 18; LLS 52 to 60; GR 6 or 7 + 18 to 20; BD ~ 2.2 SL; maximum size to 150 mm SL


Duration in captivity (yr): 2

Size (mm): 102 mm SL, 122 mm TL

Broodstock notes: Animals housed in a small exhibit tank with few other common reef species. Identification of eggs from tank based on fact that Pempheris schomburgkii was the only species in the tank with more than one individual present. (Parthogenesis has not been documented in any of the single-individual species present in the tank and is not a plausible explanation for the presence of fertile eggs.)

Physical differences: None apparent (sex ratio determined by necropsy)

Adult diet: Frozen zooplankton, chopped shrimp, smelt, clam, squid, and a prepared gelatin based food. 2 – 3 feedings per day.

Pre-spawning activity: none

Time spawning began: overnight, most likely near dawn.

Area spawning occurred: n/a

Frequency of spawning: every 2 – 4 nights

Egg description: n/a

Approximate quantity: 400 – 500

Size: 1.38 mm

Egg changes / development: 0 – 12 hours; eggs are clear with huge yolk and a cluster of small oil droplets. By 12 hours of age eyes and notochord begin to develop. By 20 hours melanophores are present all over egg and embryo. Heart is well developed and beating by 24 hours.

Incubation period: 30 – 40 hours

Time hatching occurred: n/a

Size of hatching larvae: 3.84 mm

Yolk sac present?: Yes

Newly hatched appearance: Large finfold surrounds body. Hatchling still has oil dropletss associated with gut. Red melanophores all over finfolds and body. Newly hatched larvae are very fragile, weak swimmers, and are easily damaged by adhering to bottom, overflow screens, surface meniscus, etc. Not attracted to light until the eyes are pigmented.

Transfer / removal method: Eggs were collected from the tank by dragging a fine mesh Hagen® dip net near the bottom of the tank. The eggs were slightly negatively buoyant so the action of the net helped to lift them off of the bottom.


Spawning tank size (liter): 1200 liters ( 317 gallons) Cylindrical acrylic cylinder with ~30% covered by a decorative gray fiberglass on two sides- 76 cm diameter (36″) by 182 cm tall (72″)

Lighting & photoperiod: 28 watts actinic blue fluorescent- 14 hours summer, 11 hours winter. 28 watt full spectrum fluorescent- same photoperiod. Seasonal sunlight from large window near tank. Average distance of lighting from surface / organism 20 / 35 cm (8 – 14″). Bulbs are changed yearly.

Filtration: Standard flow undergravel, cannister filter with floss medium. Commercially prepared salt mix with filtered city water. 20 – 50% changes weekly.

Additives, medications added : Copper sulfate, as needed to maintain 0.15 ppm when symptoms were observed. This is usually continued for 30 days.

Water temperature (F): 77 winter; 82 summer. fluctuation 2\F

Salinity: 30 ppt, measured with refractometer

pH: 7.8 – 8.0 measured with a Hanna pH meter

Nitrate: 25 ppm (average) measured with cadmium reduction method, spectrophotometry


Fry development / changes: Hatching started at approximately 30 hours with all eggs hatched after 40 hours. Eyes started to develop pigment at 52 hours. Gut, mouth parts fully formed and eyes pigmented at approximately 80 hours. Yolk was fully absorbed and the larvae began feeding at this point. Specimens were observed to have rotifers in their gut upon examination. The finfold and oil droplet was still present, however, and the larvae had poor buoyancy control and were not strong swimmers. Mortality at this stage was attributed primarilt to difficulty in keeping larvae off the sides and bottom of the tank.

First food offered: rotifers, introduced at approximately 60 hours.

Second food offered: none

Survival 1st week(%): 80 %

2nd week: 0 %


Rearing tank size (liter): Larvae reared in 45 cm diameter (18″)individual tubs with sloped bottoms of approximately 15 liters ( 6 gallons) with a total system capacity of approximately 380 liters (100 gallons)with a water depth of 20 cm (8″).

Sides of tank covered? solid black fiberglass tubs

Lighting & photo period: 25 watt incandescent on continually. 40 watt full spectrum fluorescent – 8 hours. Bulb(s) are approximately 90 cm (36″) from the surface / organism. Bulbs changed as needed.

Filtration: Fluidized sand bed, UV sterilization, bag filter (50 micron). Overflows have 100 micron screens. Commercially prepared salt mix with less than 10% daily water changes.

Additives and dosages: none

Water temperature (F): 79, 1 – 2\F nightly fluctuations.

Salinity: 32 ppt, measured with refractometer

pH: 8.0 – 8.2

Nitrate: 5 – 10 ppm


Original description: Described in 1848 by J. Müller & F. H. Troschel in R. E. Schomburgk’s The History of Barbados; comprising a  geographical description of the island and an account of its geology and natural productions. London. i – xx 1 -722, 7 pls. Validated by C. R. Robins & G. C. Ray in, A field guide to Atlantic coast fishes of North America. The Peterson Field Guide Series. Boston. 1986: iii-xi, 1 – 354. [with illustrations by John Douglass and Rudolph Freund.]

Word origin: The genus Pempheris is a Greek word meaning “a kind of fish”. The genus schomburgkii is named in honor of 19th century ichthyologist R. H. Schomburgk. Schomburgk is undoubtedly well respected as there have been 16 descriptions of species of different genera bearing his name; six having been validated and one pending before the ICZN. The species designation has two spelling variations; ending with one or two “i”‘s.

Vernacular name(s): Glassy Sweeper, Copper Sweeper

Suggested reading:

Burgess, W. E., Axelrod, H. R. & Hunziker, III, R. E., Atlas of Marine Aquarium Fishes, Second Edition, 1990, T. F. H. Publications, One T. T. H. Plaza, Neptune City, NJ 07753, TFH-H-1100, ISBN 0-86622-896-9 (color photo, page 322)

Kaplan, Eugene H., A Field Guide to Coral Reefs of the Caribbean an Florida, 1982, Houghton Mifflin Company, 2 Park Street, Boston, MA 02108, ISBN 0-395-31661-8 (brief description page 233)

Randall, John E., Caribbean Reef Fishes, 1968 (1st edition), T. F. H. Publications, Inc., T.F.H. Building, 245 Cornelison Avenue, Jersey City, NJ, 07302, TFH-H-932, (description, page 155-6)

Spotte, Stephen, Captive Seawater Fishes: Science and Technology, 1992, Wiley- Interscience Publication, John Wiley & Sons, Professional, Reference and Trade Group, 605 Third Avenue, New York, NY, 10158-0012, USA, ISBN 0-471-54554-6 (discussion of schooling behavior, page 280, 697)

Thresher, R. E., Reproduction in Reef Fishes, 1984, T. F. H. Publications, Inc., 211 West Sylvania Avenue, Neptune City, NJ, 07753, USA, ISBN 0-87666-808-2 (brief discussion of family with one reference to this species, page 32)

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. 1999

One Comment

  • Manabu Bessho-Uehara

    September 29, 2020, 12:29 am

    Dear author,

    I wonder if you can find this message because it has been 20 years since you first posted.
    I am a researcher who study bioluminescent fish. I was surprised to hear that P. schomburgkii is able to be reared in the aquarium. Do you (or your aquarium) still keep the fish? and continuously raring eggs?

    P. schemaburgkii has a light organ which is resembled to the closely related fish Parapriacanthus ransonneti. This amazing fish steals luminescent protein and chemical substrate to make light from the luminous ostracod. P. ransonneti is kept in many aquarium in Japan and as far as I know, none of them can rare the egg, which limits further fundamental research, such as development of light organs.

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