Description of a New Species of Pranesus 
(Atherinidae: Pisces) from the Capricorn Group, 
Great Barrier Reef 
D. J. Woodland 1 
During 1956-7 Richard J. Slack -Smith, De- 
partment of Zoology, University of Queensland, 
and the author investigated the fish fauna of 
Heron Island, Capricorn Group. A check list of 
the recorded species is to be published conjointly 
( Pap. Dep. Zool. Univ. Qd. ) . The fish described 
here is one of a number of new species collected 
at the island. 
SUBFAMILY TAENIOMEMBRADINAE Schultz 
GENUS Pranesus Whitley 
Pranesus capricornensis, sp. nov. 
HOLOTYPE: 93 nim. standard length, from 
reef flat, Heron L, Aug. 1956, collected by R. J. 
Slack-Smith, Queensland Museum no. 1/8201. 
faratypes: Queensland Museum nos. 1/8202 
-5; 4 specimens, 69, 78, 85, and 88 mm.; 85 and 
88 mm. fish taken along with holotype, 69 and 
78 mm. fish collected by Woodland, Mar. 1957, 
reef flat, Heron I. 
DESCRIPTION: Dorsal rays ¥11 ( V -VI.t ) 1,1,8 
(9); anal I,i,12 (to 14); pectoral I,i,15; ventral 
1,5; caudal i,8 + 7,i. Scales from upper limit of 
gill opening to root of caudal fin 47 ( 46 ) ; me- 
dian predorsal scales 21 (20); scales from ori- 
gin of first dorsal to midline of belly 6 l /j. Gill 
rakers on first right gill arch 5 (6) + l + 19 
(to 22). 
Depth 5.0 ( 4.8-5. 1 ) ; head 4.2 (4.0-4.2); 
snout to first dorsal origin 1.75, to centre of anus 
1.9, to anal origin 1.5 (1.4); all in standard 
length. Snout 4.5 (42-4.6); eye 2.4 ( 2.2— 2.4) ; 
tip of snout to rear of maxilla 2.8 (to 3.2 ) ; least 
depth of caudal peduncle 3.2 (to 3.4) ; postorbi- 
tal length of head 2.2 (2. 1-2.3 ) ; distance be- 
tween dorsal origins 1.5 ( 1.4) ; length of longest 
ray of pectoral fin 1.3 (1.2); interorbital space 
1 Department of Zoology, University of Queensland, 
Brisbane. Present address: Zoology Department, Uni- 
versity of New England, Armidale, N. S. W. Manu- 
script received December 20, I960. 
2.8 (2. 6-2. 8) ; all in length of head. Least depth 
of caudal peduncle in its length 2.4 (2. 0-2 .4). 
Lateral band broad, its greatest width 1.5 in 
postorbital length of head ( counts and measure- 
ments from holotype, with ranges exhibited in 
the four paratypes included in brackets ) . 
Premaxilla with front margin slightly convex; 
teeth minute on dentary, vomer, and palatines, 
on premaxilla giving a shagreen-like finish to 
outer surface; air bladder and body cavity end- 
ing bluntly in front of anal origin; bony edge 
of preopercle with concavity near lower poste- 
rior corner; gill rakers long and slender, longest 
l A as long again as diameter of pupil; maxilla 
reaching to halfway between vertical lines 
through anterior margins of orbit and pupil; 
centre of anus posterior to tips of depressed 
ventrals, 1.5 vertical scale rows distant from 
tips; vertical line through anus passing through 
fourth scale in front of first dorsal origin; anal 
fin origin under third scale in front of second 
dorsal origin; posterior margins of scales smooth; 
ascending premaxillary process short, broad 
based, not entering interorbital space (Fig. la); 
mandible without an abrupt elevation poste- 
riorly on each ramus (Fig. lb). 
The sequence employed in listing descriptive 
characters is after Schultz et d. (1953). The 
formula for recording fin counts is that now in 
use in many taxonomic works: upper case Ro- 
man numerals for spines or, as in this instance, 
nonstriated rays; lower case Roman numerals for 
striated, unbranched rays; and Arabic numerals 
for branched rays. 
DIAGNOSIS: P. capricornensis cannot be dis- 
tinguished from its congeners on any single fea- 
ture. Combination of the following characters 
is diagnostic: the broad lateral band; the scale 
row count from upper limit of gill opening to 
caudal fin base; and the position of the anus 
relative to the tips of the depressed ventrals and 
first dorsal fin origin. 
540 
