Diagnoses for Leiognathus Lacepède 1802, Equula Cuvier 1815, Equulites Fowler 1904, Eubleekeria Fowler 1904, and a New Ponyfish Genus (Teleostei: Leiognathidae)
Author
Chakrabarty, Prosanta
Author
Sparks, John S.
text
American Museum Novitates
2008
2008-08-28
3623
1
1
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http://www.bioone.org/perlserv/?request=get-abstract&doi=10.1206%2F618.1
journal article
10.1206/618.1
0003-0082
5389649
Karalla
,
new genus
Figure 6
Clade G, in part:
Sparks
et al.
2005
.
TYPE
SPECIES
:
Karalla daura
(
Cuvier, 1829
)
.
OTHER INCLUDED SPECIES
:
Karalla dussumieri
(Valenciennes, in
Cuvier and Valenciennes, 1835
).
DIAGNOSIS: Members of
Karalla
are distinguished from all other leiognathids by either the presence of a deep golden coloration on the flank or a weakly retrognathous lateral snout outline.
ETYMOLOGY:
Karalla
is the local name for ponyfishes in
Sri Lanka
and the surrounding region where members of this genus commonly occur. This generic epithet is genderneutral.
REMARKS:
Karalla
can be further distinguished from other leiognathids by the combination of a scaled nuchal region, an elongate rhomboid body, and the presence of two welldeveloped (vs. weak) prongs on the anterodorsal margin of the cleithrum (fig. 7). The presence of two prongs on the anterodorsal margin of the cleithrum is a synapomorphy of
Leiognathidae
; however, this feature is more prominent in
Karalla
than most other genera (fig. 7). Members of
Karalla
also possess a distinct golden or deep yellowish-green coloration in life that differs from the bright yellow coloration of some species of
Nuchequula
.
The relationship between
Karalla
and
Nuchequula
was unresolved in the analysis of
Sparks et al. (2005
;
Karalla daura
was recovered as more closely related to
Nuchequula
than to
K. dussumieri
); however, members of both genera were recovered together as a monophyletic group in that study.
Nuchequula
is recovered with strong support as the sister group to
Karalla
in the phylogenetic analysis of Chakrabarty et al. (MS). This clade comprising
Karalla
and
Nuchequula
is in turn recovered as the sister group to
Photoplagios
(fig. 1).
Karalla
can be easily distinguished from
Nuchequula
by the absence of a prominent nuchal marking, whereas the presence of a nuchal marking is a synapomorphy of the latter genus (
Chakrabarty and Sparks, 2007
).
Karalla daura
can easily be distinguished from all other leiognathids by the presence of enlarged fleshy lips and by the presence of a broad, golden horizontal stripe along the midline of the flank, which surrounds the entire lateral line from the orbit to the caudal peduncle, and is as deep as the arc of the lateral line vertically (fig. 6A). In contrast,
K. dussumieri
lacks a distinct golden stripe. Instead, a diffuse golden coloration is present on the flank punctuated by dark, yellow-green vermiculate lines over the dorsal half of the body. In addition,
K. daura
also possesses a large dark blotch on the spinous dorsal-fin membrane, a feature lacking in
K. dussumieri
(fig. 6B).