An Inconvenient Monophyly: An Update on the Taxonomy of the Groupers (Epinephelidae)
Author
Ma, Ka Yan
Simon F. S. Li Marine Science Laboratory, School of Life Sciences, The Chinese University of Hong Kong, Sha Tin, 999077, Hong Kong SAR.
Author
Craig, Matthew T.
2 National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Southwest Fisheries Science Center, 8901 La Jolla Shores Drive, La Jolla, California 92037
matthew.craig@noaa.gov.
text
Copeia
2018
2018-10-31
106
3
443
456
http://dx.doi.org/10.1643/ci-18-055
journal article
298900
10.1643/ci-18-055
4919bfd6-3d35-48b9-9421-c852fa35abab
12536069
Plectropomus
and Its Allies.
—The genus
Plectropomus
was recovered as monophyletic; however, both the monotypic
Gonioplectrus
and
Saloptia
are included in a larger monophyletic clade. All three genera share a relatively low dorsal-fin spine count (7–8 vs. 9–11 in the remaining grouper genera). Smith (1964), Leis (1986), and Heemstra and Randall (1993) hypothesized a close relationship between
Saloptia
and
Plectropomus
. Species in these genera are the only groupers with a single supraneural bone, low dorsal-fin spine count, three large antrorse spines on the lower edge of the preopercle, and only 13 branched caudal-fin rays.
Saloptia
has been treated as a monotypic genus on the basis of the relative strength of the median fin spines (‘‘strong’’ in
Saloptia
and ‘‘weak’’ in
Plectropomus
; Heemstra and Randall, 1993) and an absence of enlarged canine teeth on the lower jaw. Given the numerous synapomorphies shared by these genera, the argument for retaining
S. powelli
in a monotypic genus is relatively weak. The loss of canine teeth appears to be an autapomorphic character and is insufficient to exclude the species from
Plectropomus
.
FIG. 7.
Epinephelus altivelis
juvenile (top) and adult (bottom). Photographs
©
Robert Myers.
The monotypic genus
Gonioplectrus
is also present in this clade (clade A,
Figs. 1
,
2
). This is not entirely surprising as it shares the low number of dorsal-fin spines (8) with species of
Plectropomus
.
Gonioplectrus
has two well-developed supraneurals (versus only one in
Plectropomus
and
Saloptia
), 15 branched caudal-fin rays (versus 13 in
Plectropomus
and
Saloptia
), a prominent knob on the lower corner of the maxilla (absent in
Cephalopholis
,
Plectropomus
, and
Saloptia
) and unique cranial morphology (Heemstra and Randall, 1993). Given these differences,
Gonioplectrus
appears to be a related, but distinct genus and is retained for the single species
G. hispanus
.
Also included in the monophyletic clade A (
Fig. 1
) are members of the genus
Variola
. With nine dorsal-fin spines, this genus would seem to be closely related to
Cephalopholis
; however, it is clear from the analyses that this is not the case. Species of
Variola
are the only grouper species with a pronounced, lunate tail. While closely allied with
Plectropomus
and
Gonioplectrus
, the genus
Variola
appears to be a distinct group among the groupers with low dorsal-fin spine counts and is therefore retained.