Download Dwarf flat-headed gudgeon - Murray

NATIVE SPECIES
Common Name
Dwarf flat-headed gudgeon
Uncommon
Photo: Gunther Schmida
Scientific Name Philypnodon macrostomus Hoese & Reader 2006
Male in breeding colouration
Identification
A small, fish with a truncate to rounded tail.
Maximum length 65 mm; rarely more than
40 mm. The head is broad and flat with a
large mouth. Males have a larger mouth,
extending beyond the rear margin of the
eye, whereas in females it extends to below
the middle of the eye. The gill openings
on the underside of the head are narrow,
extending forward to below the posterior
portion of the gill covers, ending well behind
the eye. It has two separate dorsal fins. The
upper head and body is brown to black with
irregular blotches, and a vertical black bar
on the base of the caudal fin. Two black
oblique bands extend backwards from the
eye. The first dorsal fin has two black bands
interspersed with orange or whitish areas. The
second dorsal fin has 3–4 black stripes, also
interspersed with orange or whitish areas. The
caudal fin has orange spotting.
This species can be easily confused with
small individuals of Flat-headed gudgeon but
can be distinguished by: the narrower gill
openings which do not extend to, or below
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the eye; the smaller number of pectoral fin
rays (15–16); and the black bar at the base of
the tail.
This recently described species is variable
in morphology across its range, with some
Murray-Darling populations differing in body
patterning and pre-dorsal scalation to the
taxon described from coastal drainages near
Coffs Harbour. Further taxonomic work is
required. Dwarf flat-headed gudgeon has also
been confused with Philypnodon grandiceps,
and some references to P. grandiceps prior to
1980 probably refer to Dwarf flat-headed
gudgeon.
Biology and Habitat
Dwarf flat-headed gudgeon reportedly prefer
relatively calm waters and occur over mud and
rock substrates or in weedy areas. However,
recent information from coastal populations
in southeastern Queensland indicates that
this species occurs over coarser substrates such
as gravel and cobbles, close to submerged
cover such as leaf-litter accumulations, woody
habitat and aquatic vegetation. Nothing is
F i s h e s o f t h e M u r r ay- D a r l i n g B a s i n
ID Valley
1 Avoca
2 Border Rivers
3 Broken
4Campaspe
5Castlereagh
6Central Murray
7Condamine
8Darling
9Goulburn
10Gwydir
11 Kiewa
12 Lachlan
13 Loddon
14 Lower Murray
15 Macquarie
16 Mitta Mitta
17 Murrumbidgee
18Namoi
19Ovens
20 Paroo
21Upper Murray
22 Warrego
23 Wimmera
known of the reproductive biology in the
wild, and little is known of its general ecology
in the Basin. In aquaria it has been recorded
breeding at temperatures of 19–22°C. The
eggs are transparent and teardrop shaped, and
hatch in 4–5 days. The male fish guards the
egg mass, fanning them regularly and driving
away other fish.
The Dwarf flat-headed gudgeon is a benthic
carnivore, feeding mainly on aquatic insects
and their larvae such as chironomids, mayflies
and caddisflies.
Distribution and Abundance
Dwarf flat-headed gudgeons are relatively
common in coastal streams from southern
Qld to Wilsons Promontory in Vic, and there
are some outlying coastal populations near
Adelaide in eastern SA. They occur also in the
inland MDB but are patchily distributed and
have only been recorded from a few localities.
It is known from the Macquarie drainage near
Bathurst, the Murrumbidgee near Canberra,
the Boorowa River near Boorowa, the upper
Murray near Albury, the Condamine near
An introductory guide
Condamine and Chinchilla, and the Lower
Lakes and Mount Lofty Ranges in SA. It has
also been reported from wetlands and edges
of the lower Murray River up to Torrumbarry
weir. In the first two sampling rounds of the
Sustainable Rivers Audit covering 16 river
valleys encompassing 351sampling sites,
only 9 individuals were captured, all from
the Lower Murray. The species has not been
recorded from the ACT.
Potential Threats
None known. Predation (larval and adult) by
alien fishes and interaction with the aggressive
Eastern gambusia may be threats.
General References
Allen et al. 2002; Fletcher 1997; Hammer
2004; Higham et al. 2005; Hoese & Reader
2006; Koehn & O’Connor 1990; Larson &
Hoese 1996a; Lintermans & Osborne 2002;
Lloyd & Walker 1986; Merrick & Schmida
1984; Pusey et al. 2004; Wedderburn &
Hammer 2003.
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Published by the Murray-Darling Basin Commission
Postal address: GPO Box 409, Canberra ACT 2601
Office location: Level 3, 51 Allara Street, Canberra City ACT
Telephone: (02) 6279 0100, international + 61 2 6279 0100
Facsimile: (02) 6248 8053, international + 61 2 6248 8053
Email: [email protected]
Internet: http://www.mdbc.gov.au
For further information contact the Murray-Darling Basin Commission office on
(02) 6279 0100
This fish fact sheet is an extract derived from the report:
Lintermans, M. 2007, Fishes of the Murray-Darling Basin: An introductory guide.
MDBC Publication No. 10/07
ISBN 1 921257 20 2
© Murray-Darling Basin Commission 2007
This work is copyright. Graphical and textual information in the work (with the exception of
photographs, artwork and the MDBC logo) may be stored, retrieved and reproduced in whole
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(Fishes of the Murray-Darling Basin) is acknowledged. Such reproduction includes fair dealing
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F i s h e s o f t h e M u r r ay- D a r l i n g B a s i n