A revision of the water beetle genus Hydraena Kugelann for southern Africa (Coleoptera: Hydraenidae)
Author
PERKINS, PHILIP D.
text
Zootaxa
2014
2014-01-29
3758
1
1
92
http://dx.doi.org/10.11646/zootaxa.3758.1.1
journal article
5965
10.11646/zootaxa.3758.1.1
903b427b-6b4f-4f0b-9270-1459a7e5be1e
1175-5326
5037597
63F695AA-891F-48D2-AE96-7492016B9590
Hydraena
Kugelann, 1794
Hydraena
Kugelann, 1794: 578
(
type
species
Hydraena riparia
Kugelann 1794: 579
).
The speciose, cosmopolitan genus
Hydraena
is well defined by the following autapomorphic morphological characteristics: 1) presence of a labral-mandibular interlocking device (Perkins 1989), 2) mentum with an acute median projection anteriorly (Perkins 1989), 3) various complex sensilla (
Perkins 1997
), and 4) specialized features of the exocrine secretion delivery system (
Perkins 1997
). There is general agreement among current workers that
Hydraena
is monophyletic, based on these morphological characters (for example, Jäch
et al
. 2000).
In a recently published landmark paper (
Trizzino
et al.
2013
) the phylogeny of
Hydraena
was reconstructed using 212 species plus several outgroups and approximately 4 kb of sequence data from two nuclear (
SSU
and
LSU
) and four mitochondrial genes (
cox1
,
rrnL
,
trnL
and
nad1
). The study found strong support for the monophyly of
Hydraena
and many of the clades that have been recognized on the basis of morphological data. The following clades were considered by
Trizzino
et al.
(2013)
as subgenera:
Phothydraena
Kuwert
,
Spanglerina
Perkins
,
Holcohydraena
Kuwert
,
Hydraenopsis
Janssens and
Hydraena
s.str.
The placement of three species groups, two Neotropical (
H. multispina
group,
H. paeminosa
group) and one South African/Madagascan (
H. monikae
group), was found to be uncertain, and they were considered
incertae sedis
within
Hydraena
.
The study by Trizzino
et al.
included four southern African species of
Hydraena
. Two of the species,
H. accurata
and
H. cooperi
were found to be members of the subgenus
Hydraenopsis
. Two other species that were sequenced, represented by
one specimen
each, were
H. monikae
and
H.
sp.; these were determined to be in the same, subgenerically uncertain, clade (=
H. monikae
group). The second species ("
H.
sp.") is a member of
H. duodecimata
.
Based on morphological similarity, five species are herein placed in the
Monikae
Group. The 24 other species are quite similar in basic morphology to
H. accurata
and
H. cooperi
, and are consequently placed in the subgenus
Hydraenopsis
. More DNA sequence studies are needed to corroborate these placements.