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Fishery Bulletin 96(4), 1 998 
pressed teeth with an incisorlike shape (Norman, 
1934; Sakamoto, 1984a). Both of these tooth struc- 
tures in Limanda are interpreted as synapomorphies 
for the Pleuronectini. There is little evidence in sup- 
port for the monophyly of Limanda . Only one char- 
acter state is shared by all six species: presence of 
gill rakers on second epibranchial (30, Fig. 30. This 
character is a reversal of a reduced number of gill 
rakers defining the second lineage of Pleuronectinae 
(Fig. 6). There were 16 trees of 403 steps that hy- 
pothesized a monophyletic Limanda based on three 
reversals (Fig. 18D), including the presence of gills 
rakers on the second epibranchial. All 16 topologies 
were correlated with a hypothetical alternative to 
the consensus tree (Fig. 18D) such that a monophyl- 
etic hypothesis for Limanda is not resolved by con- 
sensus and is therefore not robust to the homoplasy 
observed in the analysis. However, the placement of 
these six species near the base of the second lineage 
in Pleuronectini and the shared morphological char- 
acters mentioned above suggest that a conservative 
approach to their nomenclature should be considered 
and that these six species should remain classified 
as Limanda until a more focused phylogenetic analy- 
sis is performed. 
Genus Platichthys This genus contains three 
species: P. bicoloratus, P. flesus, and P. stellatus. It is 
monophyletic with five synapomorphies (Fig. 17): 
scales along median fins absent (104), a possible re- 
versal in Pleuronectidae; scales on the body modi- 
fied to form bony tubercles (105); gill rakers on sec- 
ond and third epibranchial absent (30, 31); and 
supra temporals on ocular and blind sides are fused to 
the cranium ( 106). Absence of gill rakers on the second 
epibranchial is observed only in the distant lineage 
Verasper. The absence of gill rakers on the third 
epibranchial also occurs in Verasper and Pleuronectes 
platessus. The ocular-side supratemporal fused to the 
cranium is homoplastic in Limanda punctatissima. 
Genus Pleuronectes This genus contains five 
species: P. glaeialis, P. pinnifasciatus, P. platessus, 
P. putnami, and P. quadrituberculatus . The mono- 
phyly of these five species was observed in 112 of 
128 trees (87.5%) and is supported by two synapo- 
morphies (Fig. 17): prominent dorsal crest extend- 
ing from the supraoccipital to the blind-side frontal 
(52, Fig. 10, B and C); and presence of molariform 
teeth on fifth ceratobranchial (72, Fig. 3D). A promi- 
nent crest extending from the supraoccipital to blind- 
side frontal is a reversal within Pleuronectini, that 
is also observed in Limanda aspera. The presence of 
molariform teeth on the fifth ceratobranchial is only 
shared with Platichthys bicoloratus . 
Alternative topologies observed in 16 of 128 trees 
( 12.5%) place species of Pleuronectes as paraphyletic 
with Platichthys stellatus , P. flesus, and P. bicoloratus 
at the terminal end (Fig. 18D). This topology does 
not contradict the synonymy of Liopsetta ( sensu 
Norman) within Pleuronectes. It does contradict the 
classification of Platichthys. However, as previously 
illustrated, the alternative topologies for the 
intrarelationships within Pleuronectini are based on 
homoplasy observed in Limanda such that the 
paraphyletic origin in Pleuronectes is correlated and 
observed in the same 16 trees indicating monophyly 
of Limanda (Fig. 18D). 
Genus Pseudopleuronectes This genus contains 
five species: P. americanus, P. herzensteini, P. 
obscurus (not examined), P. yokohamae, and P. 
schrenki. The monophyletic status of this group is 
supported by three synapomorphies (Fig. 17): ante- 
rior margin of mesethmoid forming a thin plate (53, 
Fig. 8B); blind-side nasal bone absent (50); and dem- 
ersal eggs (75). Pseudopleuronectes obscurus has 
character states synapomorphic for the fourth lin- 
eage of Pleuronectinae, uniting Pleuronectes and 
Pseudopleuronectes . These are the presence of 
incisorlike teeth forming a continuous cutting edge and 
close approximation of the fifth ceratobranchials 
(Norman, 1934). Although teeth on the fifth cerato- 
branchial are bluntly conical (Norman, 1934), as in 
Pseudopleuronectes , this character state is plesio- 
morphic at this phylogenetic level. However, presence 
of a demersal egg in P. obscurus (Hensley andAhlstrom, 
1984), is synapomorphic for Pseudopleuronectes. 
Homoplasy and two exceptions observed in these 
morphological characters do not corroborate an al- 
ternative hypothesis. A clade uniting the four spe- 
cies of Pseudopleuronectes examined here, is observed 
in all 128 equally parsimonious cladograms. The thin 
plate structure of the mesethmoid is also observed 
in Pleuronectes platessus, and in more distant taxa, 
Pleuronichthys uerticalis, Dexistes rikuzenius, and 
Hippoglossoides. The absence of a blind-side nasal 
bone is homoplastic in Pleuronectes platessus and 
Limanda (except L. sakhalinensis). It is also observed 
outside of Pleuronectini in Microstomus bathybius , 
Pleuronichthys (except P. guttulatus ), Cleisthenes, 
and Hippoglossoides . A demersal egg is not observed 
in P. herzensteini and is homoplastic in Lepidopsetta. 
Summary of intrarelationships 
The species examined in this analysis (53 of 59), rep- 
resent the complete range of morphological variation 
found in the family. The character analysis outlines 
the characters synapomorphic for clades revealed in 
the consensus tree (Fig. 1). 
The Pleuronectidae can be summarized as compris- 
ing large piscivorous species at the basal lineages, 
