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.

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Breeder ID:OPIAUR-070595-SOWDAV-006

Date received: 7/5/1995

Identification: Opistognathus aurifrons (Jordan & Thompson, 1905)

Geographic Origin: Caribbean

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

Kingdom Animalia

Phylum Chordata Subphylum Vertebrata

Class Osteichtyes Subclass Actinopterygii Infraclass Teleostei

Superorder Acanthopterygii Order Perciformes Suborder Trachinoidei

Family Opistognathidae

Genus Opistognathus (Cuvier 1816)

Species aurifrons (Jordan & Thompson, 1905)

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Description: Dorsal rays XI, 15 to 17; anal rays III, 14 to 16 (rarely 14); pectoral rays 19 to 21 (rarely 21); lateral scale rows posterior to opercular flap 81 to 94; gill rakers increasing with age, those of lower limb varying from 17 in young to 37 for adults; pelvic fins long; 68 to 96 mm standard length. Sexually monomorphic, although males are observed to have a pronouncedly enlarged head during courtship. This species is native to the Florida waters and in the wild spawns from spring to late fall (Colin, 1972). Pairing in this species appears to be long term. The species is slender in body form. Coloration of body is pearlescent white to light bluish-gray and yellow coloration around the eyes, nape (forehead), anterior portion of dorsal fin and occasionally jaws. The species requires a coarse substrate in which to construct its burrow. The species is generally very shy and retreats quickly into the safety of its burrow. It has been suggested by one source that a separate burrow is used for spawning (although this has not been documented).

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Duration male(yr): 2.0

Size male (mm): not indicated

Duration female 1 (yr): 0.6

Size female 1 (mm): not indicated

Broodstock notes: Second time pared. Female was during first attempt

Physical differences: Male is larger with a more rounded head

Adult diet: Live Artemia, formulated foods. Fed 2 x day

Pre-spawning activity: not observed

Time spawning began: not indicated

Area spawning occurred: not indicated

Frequency of spawning: 9 days, irregular

Egg description: large mass

Approximate quantity: 300-500

Size: 3 mm

Egg changes / development: egg mass turns silver with development

Incubation period: 7 days

Time hatching occurred: after dark

Size of hatching larvae:~ 3 mm

Yolk sac present? very small

Newly hatched appearance: dark with large mouths, not strongly attracted to light

Transfer / removal method: not indicated

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Spawning tank size (liter): 475

Sides of tank covered? Back, blue

Lighting & photo period: Fluorescent; Aquasun® and 50/50, 15 hrs. 3″ above surface ~ 24″ from burrow

Filtration: Algal scrubber, natural seawater from Monterey Bay

Additives and dosages: none

Water temperature (F): 78

Specific gravity: 1.023

pH: 8.4

Nitrate: > 1 ppm

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First food offered: Rotifers enriched with SELCO®, fed continuously

Second food offered: Artemia nauplii, enriched with SELCO® on day 2

Survival

1st week(%):60%

2nd week: 40%

3rd week: 1%

4th week: 0%

Development description: Metamorphosis in 18 – 22 days. Heavy losses through metamorphosis. Survivors died 1 – 7 days later

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Rearing tank size (liter): 37

Sides of tank covered? No

Lighting & photo period: Fluorescent cool white, 14 hours 6″ above surface. Twilight lighting after “night”

Filtration: none

Additives and dosages: none

Water temperature (F): 78 – 80

Specific gravity: 1.022

pH: 8.0

Nitrate: 10 – 20 ppm

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Comments: Larvae polycultured with other species

Original description: First described by Jordan and Thompson in 1905 as Gnathypops aurifrons, in Bull. Bur. Fish. v. 24 (for 1904) Fig. 4 (not fig. 6) [; ref. 2538]. From a single specimen collected at Garden Key, Dry Tortugas, Florida, U.S.A. Holotype (unique). Valid as Opistognathus aurifrons.

Vernacular name: Yellow head (ed) jawfish

Word origin: The genus Opistognathus Is from the Greek root(s) opisto meaning a snake or serpent (isto is a superlative ending); and gnathus meaning jaw. The genus aurifrons is from the Latin root(s) auri meaning gold; and frons meaning forehead or brow.

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

Colin, P. L., Daily activity patterns and effects of environmental conditions on the behavior of
the yellowhead jawfish, Opistognathus aurifrons, with notes on ecology. 1972, Zoologica, NY.
57:137-169.

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

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

Walch, John, Breeding Jawfish, 1993, The Breeder’s Registry, Volume 1, Issue 4,

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. 1995