Systematics of Indobaetis Müller-Liebenau & Morihara 1982, and related implications for some other Baetidae genera (Ephemeroptera)
Author
Kluge, Nikita J.
Author
Novikova, Eugenia A.
text
Zootaxa
2014
3835
2
209
236
journal article
10.11646/zootaxa.3835.2.3
da5d7f47-11c9-4c3b-9dfc-93a32201c1e2
1175-5326
250181
CC0686BB-FBE6-4C72-AB05-65CF2ED7A022
Indobaetis
Müller-Liebenau & Morihara 1982
(
Figs 2–75
)
Type
species:
Indobaetis costai
Müller-Liebenau & Morihara 1982
.
General characteristic given to
Indobaetis
by
Müller-Liebenau & Morihara (1982)
should be modified as the following.
Apomorphies of
Indobaetis
.
(1)
Each mandible has incisor and kinetodontium completely fused together forming an integral plate with cutting edge widened, evenly dentate and vaulted ventrally, so that its part corresponding to incisor is less projected medially than its part corresponding to kinetodontium (
Figs 46–48
;
Müller-Liebenau & Morihara 1982
:
Figs 1
f, 2f).
(2)
Prostheca of right mandible is slender and pointed, not bifurcate (
Figs 47, 48
;
Müller-Liebenau & Morihara 1982
:
Figs 1
f, 2f) (see Discussion, 2.4).
(3)
Maxilla has 2 dentisetae: 1st dentiseta (most distal) is thick and adjacent to maxillary canines (as in many other
Baetidae
); 2nd dentiseta is sharply arched and pressed to the first dentiseta, so that its middle part is hidden between the first dentiseta and the canines; 3rd dentiseta is absent; setae of median-dorsal row form a compact bunch, basally adjacent to the second dentiseta and distally diverging from it (
Figs 10
,
51
). In other
Baetidae
three dentisetae, initial for Tridentiseta
Kluge
et al
. 1995
, are retained (
Kluge 2004:
Figs 28
B, D
).
(4)
Larval tibia has a regular row of stout setae on outer margin, different from setae of a regular row on outer margin of femur (
Figs 22
,
67, 68
).
(5)
Larval claw has distal denticle enlarged, with at least one strong seta posteriad of it (
Figs 42
,
58
) (see Discussion, 2.7).
(6)
Hind
wings are absent; larva has no vestiges of hind protoptera (
Müller-Liebenau & Morihara 1982
:
Figs
1
i,
2g
).
(7)
Tergalii of first pair are lost, only 6 pairs of tergalii are present.
(8)
In mature larva buds of subimaginal gonostyli are folded by «
Labiobaetis
-
type
» (
Figs 28, 29
); this character is known only for
I. costai
(see Discussion, 2.10)
(9)
On fore leg of female subimago and imago 1st tarsomere is completely fused with 2nd tarsomere, so the tarsus is 4-segmented (
Figs 2–5
), like tarsi of middle and hind legs (
Fig. 11
). This character is known for
I. costai
and
I. microfolius
sp.n.
In most other
Baetidae
fore tarsus of female subimago and imago has 1st tarsomere well separated from 2nd tarsomere (
Fig. 1
) (see Discussion, 2.12).
Character of
Indobaetis
of unclear phylogenetic polarity.
(10)
In subimago, 1st and 5th tarsomeres are covered mainly with pointed microlepides, other tarsomeres mainly with blunt microlepides (
Figs 5–8
,
11–17
); this character is known for
I. costai
and
I. microfolius
sp.n.
(see Discussion, 2.13)
Plesiomorphy of
Indobaetis
.
(11)
Sterno-styligeral muscle is retained (
Figs 21
,
24
,
54
); this character is known for
I. costai
and
I. microfolius
sp.n.
(in contrast to
Labiobaetis
, Baetosternata
and some other taxa, whose sterno-styligeral muscle is completely lost—see Discussion, 2.11).
Characters variable among species of
Indobaetis
.
Larval habitus varies from
Nigrobaetis
-like in
I. costai
and
I
.
starmuehlneri
(i.e., with head bowed ventrally, head and thorax laterally compressed, three caudalii and their primary swimming setae well developed) to
Acentrella
-like in
I. microfolius
sp.n.
(i.e., head and thorax flattened ventrally, paracercus reduced, and swimming setae lost). Frons varies from narrow and keeled to wide and flat (
Figs 40, 41
,
55
). Maxillary palp, being 2-segmented (as in all Baetungulata), has 2nd segment either incised (in
I. costai
), or not (in other species—Fig. 51). Transverse row of fine setae on glossa is either present (in
I. costai
and
I. starmuehlneri
), or absent (in
I. microfolius
sp.n.
—
Fig. 50
). Labial palp either has structure usual for
Baetidae
(in
I. starmuehlneri
), or has 2nd segment unusually narrowed (in
I. costai
), or has 2nd and 3rd segments completely fused together and lacking muscle (in
I. microfolius
sp.n.
—
Fig. 52
). Patella-tibial suture, being equally developed on all legs (that is characteristic for Anteropatellata), either has normal shape (in
I. costai
and
I. starmuehlneri
—
Fig. 22
), or is smoothed and stretches along tibia (in
I. microfolius
sp.n.
—
Fig. 67
). Larval paraproct either has tongue-like denticulate prolongation of inner posterior edge (in
I. costai
and
I. starmuehlneri
—
Figs 38, 39
), or with posterior margin non-expressed (in
I. microfolius
sp.n.
—
Fig. 72
).
Distribution.
Southern
India
and
Sri Lanka
.
Species composition.
3 species:
Indobaetis costai
Müller-Liebenau & Morihara 1982
,
I. starmuehlneri
Müller-Liebenau & Morihara 1982
and
I. microfolius
sp.n.
Comments.
Selva-kumar
et al
. (2012) described
Indobaetis michaelohubbardi
based on larvae from southern
India
. Subsequent reexamination of the
type
specimens reveals that this species has hind protoptera and other characters of
Baetis
s.str.
(K.G. Sivaramakrishnan, personal communication). In the photo (Selva-kumar
et al
. 2012:
Fig. 34
) three maxillary dentisetae are visible, that allows to exclude this species from
Indobaetis
. According to the photos (Selva-kumar
et al
. 2012:
Figs 29–38
) this species belongs to subgenus
Tenuibaetis
Kang & Yang
(in
Kang
et al
.) 1994
of the genus
Baetis
s.str.
So, the valid binomen is
Baetis michaelohubbardi
(Selva-kumar
et al
. 2012),
comb.n.