New Cardinalfish from northwestern Australia 
179 
Figure 1 Drawing of holotype of Apogon unitaeniatus, 50.2 mm SL. Damaged fins are reconstructed. 
beginning of upper and lower limbs; 
branchiostegal rays 7; vertebrae 10 + 14. 
Body depth 2.5 (2.6-2.S) in SL; body width 2.3 
(2.1-2.3) in depth; head length 2.4 (2.3—2.6) in SL; 
dorsal profile of head straight except for rounded 
front of snout; snout length 3.8 (4.2-5.0) in head; 
eye diameter 2.9 (3.0-3.4) in head; interorbital 
width 4.1 (4.2-4.7) in head; caudal peduncle depth 
2.8 (2.5-3.0) in head; caudal peduncle length 1.7 
(1.3-1.8) in head. 
Mouth large, the maxilla nearly reaching a 
vertical at about rear edge of pupil, the upper jaw 
length 1.9 (1.8—2.1) in head; mouth oblique, the 
gape forming an angle of 30 to 40 degrees to 
horizontal axis of head and body; posterior edge of 
maxilla concave; supramaxilla present; lower jaw 
slightly protruding, the tip thickened and fitting 
into a median indentation in upper jaw; upper jaw 
with a band of small villiform teeth in about 10 
irregular rows on lateral portion and narrowing to 
3-4 rows anteriorly; indented median part of upper 
jaw edentate; 3-4 irregular rows of similar teeth in 
lower jaw, the anterior ones recumbent; a narrow 
band of small villiform teeth on vomer and 
palatines. Tongue broad-based, gradually tapered 
anteriorly, the upper surface with scattered 
papillae. 
Anterior nostril a small, low-rimmed tube, 
directly in front of centre of eye, about half distance 
from edge of orbit to front of upper lip; posterior 
nostril ovate without a rim, about twice size of 
anterior nostril, situated on a line connecting 
anterior nostril and top of eye. Head with 
numerous, tiny lateralis system pores, but enlarged 
pore present at front edge of snout and on middle 
of preorbital. A single, flat, obtuse opercular spine. 
Serrations on head bones scarcely evident in small 
juveniles, becoming more prominent and 
increasing in number with added growth. 
Preopercular margin weakly serrate in adults (18 
serrae on leftside of holotype, 25-40 on para types); 
preopercular ridge mainly smooth or weakly 
crenulate, except for 8 (8-20) serrae; ventral and 
posterior portion of circumorbitals with 13 (5-13) 
serrae. 
Scales ctenoid. Lateral line conspicuous, nearly 
paralleling dorsal contour of body, and ending a 
short distance posterior to caudal-fin base (5 pored 
scales posterior to hypural, the last pointed). No 
scales on dorsal and anal fins except a low sheath 
at base of second dorsal and anal fins; small scales 
on basal third of caudal fin; no scales on paired 
fins except a pair of large midventral scales at base 
of pelvic fins. 
Origin of first dorsal fin above second lateral-line 
scale; first dorsal spine slender and short, 22.8 
(14.3-22.0) in head; third dorsal spine longest, 2.3 
(2.2-2.6) in head; second soft dorsal and anal rays 
longest, damaged in holotype, but their length 1.5- 
1.9 in paratypes; origin of anal fin below base of 
fourth dorsal soft ray; first anal spine short, 12.1 
(10.3-18.6) in head; second anal spine 4.7 (2.8-3.5) 
in head; caudal fin slightly forked, its length 1.1- 
1.3 (damaged in holotype); origin of pelvic fins 
about even with pectoral-fin base; first pelvic soft 
ray longest, reaching beyond anus or beyond (to 
