TWO NEW SPECIES OF PSEUDOPLESIOPS 
second intermittent series of centrally pitted scales originating on 
midside above anterior part of anal fin, extending on to middle part 
of caudal-fin base; additional centrally pitted scales present above 
and below pitted scale(s) on middle part of caudal-fin base, some- 
times extending on to posterior part of caudal peduncle; scales 
present on cheeks (extending posteriorly over upper part of 
preopercle) and operculum (Fig. 4); predorsal scales extending 
anteriorly to point between anterior interorbital pores and vertical 
through anterior supraotic pores (Fig. 4); vertebrae 10 + 17; epurals 
2; epineurals present on vertebrae 1 through 16—18 (1 through 16); 
ribs present on vertebrae 3 through 10, rib on ultimate precaudal 
vertebra relatively long. 
Upper jaw with 2-5 pairs of curved, enlarged caniniform teeth 
anteriorly, the medial pair smallest, and 34 (at symphysis) to 1-2 
(on sides of jaw) irregular inner rows of small conical teeth, the teeth 
of outer row of conical teeth largest; lower jaw with 2-3 pairs of 
curved, enlarged caniniform teeth, the medial pair smallest, and 2— 
3 (at symphysis) to | (on sides of jaw) irregular inner rows of small 
conical teeth, the conical teeth gradually increasing in size and 
becoming more curved on middle part of jaw, then becoming 
abruptly smaller on posterior part of jaw; vomer with | row of small, 
stout conical teeth arranged in a chevron; palatines edentate or with 
small irregular patch of small conical teeth; tongue pointed, eden- 
tate. 
LIVE COLORATION. (Based on colour photograph of the holotype, 
photograph in Kuiter, 1998, and field notes taken from paratypes in 
BPBM 32871 when freshly dead) 
Head and body bright pinkish red to orange-red, becoming pink 
ventrally and olive-red to orangish brown posteriorly; margin of 
orbit orange posteriorly, becoming pale blue ventrally; posttemporal, 
intertemporal, upper preopercular and upper suborbital pores indis- 
tinctly edged with grey; iris bright orange-red; pectoral-fin base pale 
pink to pinkish red; dorsal and anal fins bright orange-red basally, 
reddish hyaline distally, with pale blue distal margin; caudal fin 
greyish yellow to pale greyish red basally, remainder of fin reddish 
to yellowish hyaline with pale blue distal margin; pectoral fin 
pinkish to yellowish hyaline; pelvic fin pale pink basally, becoming 
pale blue distally. 
PRESERVED COLORATION 
Head and body brown, paler ventrally; grey edging on posttemporal, 
intertemporal, upper preopercular and upper suborbital pores re- 
mains, becoming greyish brown; dorsal and anal fins brownish 
hyaline, becoming greyish brown distally; other fins pale brown to 
dusky hyaline. 
HABITAT AND DISTRIBUTION 
Pseudoplesiops occidentalis is known only from the Maldive Is- 
lands. It has been collected from and observed on reefs in 20 to 72 m. 
COMPARISONS WITH OTHER SPECIES 
Pseudoplesiops occidentalis forms a monophyletic group with P. 
typus Bleeker, P. rosae Schultz and several undescribed species. 
With the exception of P. occidentalis, this clade is confined to the 
eastern Indian Ocean and the West Pacific. It is diagnosed by 
scales with distinct centres and radii in all fields. Species limits 
within the clade are poorly resolved and are currently under study 
by us. For the purposes of comparison with P. occidentalis, we 
divide the clade into three subgroups, each of which we believe to 
be monophyletic: P. occidentalis, P. rosae-complex (autapomorphy: 
plate-like, median expansion of median ethmoid, pterosphenoid 
and basisphenoid into orbital space); and P. typus-complex 
(autapomorphy: all scales cycloid in adult specimens). Aside from 
the various autapomorphies listed above, the three taxa are distin- 
25 
guished from each other by the following: number of vertebrae (10 
+ 17 in P. occidentalis, 11-12 + 16-18 = 27-29, usually 11 + 17- 
18 in the P. rosae-complex and 11 + 17-18 in the P. 
typus-complex); number of dorsal-fin rays (II,23 in P. occidentalis, 
1,22—24 in the P. rosae-complex and II,24—25 in the P. typus- 
complex); number of anal-fin rays (II,14 in P. occidentalis, 
I-II,12—14, usually I,13-14 in the P. rosae-complex and II-III, 14— 
16, usually II,15 in the P. typus-complex), number of scales in 
lateral series (26—28 in P. occidentalis, 26-29 in the P. rosae- 
complex and 32-40 in the P. typus-complex); number of 
circumpeduncular scales (16 in P. occidentalis, 16 in the P. rosae- 
complex and 20-22 in the P. typus-complex); predorsal scalation 
(6-8 scales, extending anteriorly to a point between the anterior 
interorbital pores and the vertical through the anterior supraotic 
pores in P. occidentalis, 5-10 scales, extending anteriorly to a 
point between the anterior interorbital pores and the vertical 
through the anterior supraotic pores in the P. rosae-complex, and 
10-16 scales, extending anteriorly to the supratemporal commissure 
in the P. typus-complex); and cheek scalation (broadly overlapping 
the upper part of the preopercle in P. occidentalis and the P. rosae- 
complex, versus not overlapping the upper part of the preopercle in 
the P. typus-complex). Members of the P. typus-complex also 
attain a much larger body size than members of the other clades 
(largest examined specimen 53.0 mm SL versus 26.5 mm SL in P. 
occidentalis and 26.9 mm SL in the P. rosae-complex). 
Of the characters noted above that are shared by P. occidentalis 
and the P. rosae-complex, three are unique within Pseudoplesiops 
and suggest a sister-relationship between the two taxa: low number 
of scales in lateral series; predorsal scales extending anteriorly 
beyond the supratemporal commissure; and cheek scales broadly 
overlapping upper part of preopercle. This relationship will be tested 
in a study of the phylogeny of the Pseudochromidae currently in 
progress by the first author. 
REMARKS 
Colour photographs of the species are provided by Randall & 
Anderson (1993) and Kuiter (1998). Randall & Anderson indicate 
that their photograph is of a 26 mm SL specimen in BPBM 32871, 
but it is actually of the holotype (BPBM 32926). 
Regan’s (1902) specimen of the species (BMNH 1901.12.31.77) 
was initially identified and reported on as “Clinus sp.” A label on the 
jar and catalogue entry indicates that it was subsequently 
redetermined as the plesiopid Belonepterygion fasciolatum Ogilby 
(apparently by M.L. Penrith). Although we were unable to locate 
any references to this identification, they possibly exist. 
ETYMOLOGY 
The specific epithet is from the Latin, meaning of the west; P. occi- 
dentalis is known only from the western-most part of the range of the 
genus. 
ACKNOWLEDGEMENTS. We thank the following for allowing access to 
specimens in their care: G.R. Allen, A. Bentley, D. Catania, J.-P. Chen, O.A. 
Crimmen, W.N. Eschmeyer, P.C. Heemstra, D.F. Hoese, S. Jewett, J. Johnson, 
M. McGrouther, R.J. McKay, V. Mthombeni, L. Palmer, K. Parkinson, J.E. 
Randall, S.E. Reader, T. Trnski, M. Sabaj, W. Saul, K.-T. Shao, W.F. Smith- 
Vaniz, A. Y. Suzumoto, M.J.P. van Oijen and J.T. Williams. Colour photographs 
were kindly provided by J.-P. Chen, D.F. Hoese, R.H. Kuiter, J.E. Randall and 
J.T. Williams; P. Crabb took the black and white photographs of the two 
holotypes (Figs 1 and 3). O.A. Crimmen, S. Davidson, J.P. Garcia, A.-M. 
Hine, K. Parkinson, S. Raredon and S.E. Reader radiographed specimens. 
R.D. Mooi and J.T. Williams critically reviewed the manuscript and provided 
helpful comments. 
