Records of the Western Australian Museum 17: 177-180 (1995). 
A new species of Cardinalfish ( Apogon: Apogonidae) from 
northwestern Australia 
Gerald R. Allen 
Department of Aquatic Vertebrates, Western Australian Museum, Francis Street, Perth, 
Western Australia 6000 
Abstract - A new species of apogonid fish of the genus Apogon is described 
from the Northern Territory and northern Western Australia. Apogon 
unitaeniatus is described on the basis of 94 trawl-captured specimens from 
Darwin Harbour and Shoal Bay in the Northern Territory, and the Kimberley 
coast of Western Australia. It is a member of the subgenus Pristiapogon and 
very similar in appearance to A. abrogramma Fraser and Lachner of the Indo- 
West Pacific Both species are distinguished by a blackish midlateral stripe. 
However, they are readily separated on the basis of counts for gill rakers and 
pectoral rays (22-25 and 15 respectively for A. unitaeniatus versus 17-19 and 
13 for A. abogramma). 
INTRODUCTION 
Cardinalfishes of the family Apogonidae are one 
of the most abundant groups of tropical reef fishes. 
They are primarily nocturnal, although readily 
observable during daylight when they shelter in 
caves and crevices or around coral formations. The 
generic classification of Apogonidae was reviewed 
in detail by Fraser (1972), but a knowledge of the 
species composition is still incomplete. Fraser 
recognized 19 genera. The estimated number of 
species in the family is 230-250. At least half of the 
species occur in the area comprised of New 
Guinea, northern Australia, Indonesia, and the 
Philippine Archipelago. 
The present paper describes a new species of the 
genus Apogon first collected by a prawn trawler off 
the Kimberley coast of Western Australia in 1978. 
The specimens were subsequently deposited at the 
Australian Museum and were recognised in 1992 
during an examination of the institution's apogonid 
holdings. Additional specimens were procured 
during dredging operations by Rex Williams of the 
Northern Territory Museum during 1993. 
Type specimens of the new species are deposited 
at the Australian Museum, Sydney (AMS), 
Northern Territory Museum, Darwin (NTM), and 
the Western Australian Museum, Perth (WAM). 
Lengths given for specimens are standard length 
(SL), measured from the front of the upper lip to 
the base of the caudal fin (posterior end of hypural 
plate); body depth is the maximum depth from the 
base of the dorsal spines; body width is measured 
just posterior to the gill opening; head length is 
taken from the front of the upper lip to the end of 
the opercular membrane, and snout length from 
the same anterior point to the fleshy edge of the 
orbit; orbit diameter is the greatest fleshy diameter, 
and interorbital width the least bony width; caudal 
peduncle depth is the least depth, and caudal 
peduncle length the horizontal distance between 
verticals at the rear base of the anal fin and the 
caudal-fin base; lengths of fin spines and soft rays 
are measured to their extreme bases; caudal 
concavity is the horizontal distance between 
verticals at the tips of the shortest and longest 
caudal-fin rays. 
Pectoral-ray counts include the upper 
rudimentary ray; lateral-line scale counts are made 
to the base of the caudal fin (hence do not include 
the scales posterior to the hypural plate); gill-raker 
counts are made on the first gill arch; the count of 
the upper-limb rakers is given first, followed by 
the lower-limb count; the raker at the angle is 
contained in the lower-limb count. 
Proportional measurements of type specimens 
are given in Table 1 as percentages of the standard 
length. Data in parentheses in the description refer 
to paratypes. 
TAXONOMY 
Apogon unitaeniatus sp. nov. 
Figure 1 
Holotype 
AMS 1.20402-036, 50.2 mm SL, off NE portion of 
Bonaparte Archipelago, northern Western 
Australia (approximately 14°00'S, 124°45'E), 12-60 
m, prawn trawl, C. O'Conner, April 1978. 
Paratypes 
AMS 1.20402-000, 50.5 mm SL, collected with 
