Corresponding author: Alexander V. Martynov (
Academic editor: L. Pereira-da-Conceicoa
The concept of the
Martynov AV, Selvakumar C, Palatov DM, Subramanian KA, Sivaramakrishnan KG, Vasanth M, Jacobus LM (2021) Overview of Indian and Nepali representatives of the
This article is a further contribution to a series of papers (
Due to uncertain relationships of species in the genus
The
Materials from India and Nepal were used in this research. New larval material was collected by kick-net sampling and hand-picking. All of this material is stored in 80–95% ethanol. Some specimens were mounted on slides with Canada balsam or Hoyer’s medium.
The holotype of
Photographs of specimens and their body parts were taken using a Leica M205A microscope, Zeiss Stemi 2000 binocular with Canon Power Shot A 640 and Ulab XY-B2T microscope with Canon Power Shot A 630. Some figures were subsequently improved with Adobe Photoshop CS5 and Helicon Focus 6.
Our hypotheses of species are based on morphological species concepts. Two middle instar larvae from a single morphotype were collected in Nepal in 2014. These larvae belong to the
The analysis of original material, historical collections and literature data showed that there are seven species belonging to
Diagnoses of species provide characters that distinguish them within their corresponding complexes.
The following nominal species are treated in alphabetical order, with the provisional species listed at the end.
Larva of
Larva of
In late instars, femora of all legs slightly flattened (length/width ratio = fore femur 2.17–2.38; middle femur 2.56–2.86; hind femur 2.63–2.86), each one with longitudinal ridge, especially visible on middle and hind femora (Fig.
Larva of
Whole dorsal surface of fore femur with scattered middle-sized, hair-like setae; basal part of surface with group of spine-like setae, bifurcated stout setae and stout hair-like setae. Distal part of dorsal surface with narrow, transverse band consisting of irregular, sparse row of mainly long and middle-sized, pointed, bifurcated and only sometimes rounded apically, stout setae (some of them situated on chalazae) (Fig.
Dorsal surfaces of middle and hind femora covered with few hair-like setae and numerous short and several middle-sized rounded or bluntly pointed (sometimes bifurcated) apically stout setae (Fig.
Inner margins of middle and hind tibiae and tarsi densely covered with spine-like setae and stout, hair-like setae; inner margins of middle and hind tibiae also with long, pointed and bifurcated, stout setae. Outer margins of middle and hind tibiae with rows of long, pointed and bifurcated, stout setae. Outer margins of middle and hind tarsi with hair-like setae (solitary and in tufts) only.
Ventral surfaces of all tibiae and tarsi with hair-like setae (solitary and in tufts) and long, thin, pointed, stout setae; stout setae situated in apical parts of tibiae and tarsi and along their inner margins.
Tarsal claws of all legs hooked, usually with two subequal denticles (seldom with one denticle) (Fig.
Larva of
Posterior margins of terga I–II each with row of long hair-like setae; of tergum III with few long thin bluntly pointed or bifurcated apically stout setae and hair-like setae; of terga IV–VII with several rounded and pointed (sometimes bifurcated) stout setae near paired projections; of terga VIII–X with rows of short and middle-sized, mainly rounded apically, stout setae (these rows extending from paired projections to lateral margins). Lateral margins of terga IV–VIII covered with numerous short stout setae.
Pairs of pointed, not bifurcated projections present on abdominal terga II–X, with those on terga II–IV and X smaller than others; those on terga V–IX strongest (Fig.
Dorsal surfaces of abdominal gills covered with hair-like setae and scale sockets; shapes of gills as in Fig.
Caudal filaments subequal in length, with elongated, bluntly pointed or rounded (sometimes bifurcated) apically stout setae and hair-like setae at articulations (Fig.
Unknown.
The new species is named in honour of Dr. Chang-Fa Zhou (Nanjing Normal University, China), who contributed significantly to the study of the genus
The new species can be easily distinguished from other representatives of the
Known only from Nepal and northern India.
Larvae of this species were collected in middle-sized rivers (wide 4–15 m) in deep valleys, at an altitude of about 1000 m a.s.l. on the South slope of the Great Himalaya Range (India, Uttarakhand State and Bagmati Zone, Central Nepal) (Fig.
A supplemental narrative description is provided, based primarily on the study of a slide of the holotype (larva, male) and two paratypes in ethanol. Some characters are given simply as in the original description (
Larva of
Dorsal surface of head covered with numerous very short scales, empty scale sockets and short, hair-like setae.
Larva of
Mandibles (Fig.
Legs slightly flattened (length/width ratio = fore femur 2.08; hind femur 2.56), each one with longitudinal ridge (Fig.
Larva of
Tarsal claws of all legs hooked, with one large denticle and several subapical setae (Fig.
Larva of
Pairs of not bifurcated projections present on abdominal terga II–IX, relatively weakly developed (Fig.
Abdominal gills dorsal surfaces covered with hair-like setae and scale sockets; gill III oval, with somewhat extended posteromedial angles without medial, transverse band of weakened membrane. Due to slide-mounting of holotype, gills deformed and not separated from abdomen.
Caudal filaments subequal in length; middle parts with elongated stout setae with bluntly pointed or bifurcated apices (Fig.
This species can be distinguished from all other species of the
Nepal (
Adult stages unknown. The holotype (on slide) has the middle legs and one hind leg missing.
No data, but assumed to be cold water rivers and streams, based on what we know about the Trisuli River near Dhunche.
Larva of
Larva of
All femora slightly flattened (length/width ratio = fore femur 2.0–2.1; middle femur 2.0–2.2; hind femur 2.0–2.2) (Fig.
Larva of
Whole dorsal surface of fore femur covered with scattered middle-sized, hair-like setae and scale sockets with small scales in some of them; basal part of surface with group of spine-like setae, bifurcated, stout setae and stout, hair-like setae. Additionally, numerous long, bifurcated apically, stout setae covering dorsal surface of fore femora along basal half of its inner margin. Distal part of surface with relatively wide, transverse, band consisting of irregular, sparse rows of different-sized (mainly long), rounded apically (only sometimes bluntly pointed with shallow bifurcation of apex), stout setae; some of setae situated on chalazae (Fig.
Dorsal surface of middle and hind femora covered with few scattered hair-like setae and scale sockets with small scales in some of them; also, surface covered with numerous short, rounded apically, stout setae (Fig.
Inner margins of middle and hind tibiae and tarsi densely covered with spine-like setae and stout, hair-like setae; inner margins of middle and hind tibiae also with long, pointed and stout setae. Outer margin of middle and hind tibiae with irregular row of long, pointed and bifurcated, stout setae. Outer margin of middle and hind tarsi with hair-like setae (solitary and in tufts) only.
Ventral surfaces of all tibiae and tarsi with hair-like setae (solitary and in tufts) and long, thin, pointed, stout setae; stout setae situated in apical parts of tibiae and tarsi and along their inner margins.
Tarsal claw of all legs hooked, with two (rarely three) denticles distanced from each other; basal denticle (rarely two denticles) distinctly larger; distal denticle directed angled forward (Fig.
Pairs of pointed, not bifurcated, projections present on abdominal terga II–IX; those on terga V–VIII strongest; those on terga II–IV distinctly smaller than others (Fig.
Larva of
Dorsal surface of abdominal gills covered with scattered hair-like setae and scale sockets; shape of gills as in Fig.
Caudal filaments subequal in length, with mainly elongated, rounded apically, stout setae and hair-like setae at articulations.
Unknown.
The new species is named in honour of Dr. David Funk (Stroud Water Research Center, USA), who contributed significantly to the study of
The species is morphologically close to
Northern India and the India-China border region (Uttarakhand State and Arunachal Pradesh).
In Arunachal Pradesh, larvae of
In Uttarakhand State, larvae of
This species can be distinguished from other
Larva of
Thailand (
The larva of this species was properly described from Thailand by
Larva of
Cold fast-flowing river with cobbles and gravel. The Ranga River habitat is shown in
Larva of
Larva of
Larva of
In late instars, femora of all legs slightly flattened (length/width ratio = fore femur 2.00–2.17; middle femur 2.17–2.33; hind femur 2.33–2.44) and bearing longitudinal ridge, especially visible on middle and hind femora (Fig.
Larva of
Dorsal surface of fore femur with several elongated, pointed and bifurcated, stout setae with feathered margins near basal margin; also apical half of dorsal surface of fore femur with transverse, relatively wide and dense band of mainly middle-sized and short, bifurcated, bluntly pointed or rounded apically, stout setae (some situated on chalazae) (Fig.
Dorsal surface of middle and hind femora covered with numerous mainly middle-sized and short, rounded or bifurcated apically, stout setae (Fig.
Outer margins of middle and hind tibiae with regular rows of long, pointed and bifurcated, stout setae and few hair-like setae (solitary and in tufts) amongst them (Fig.
Tarsal claws of all legs hooked, with one large denticle and several subapical setae (Fig.
Larva of
Posterior margins of tergum I with row of long, hair-like setae; of terga II–III (especially tergum II) with row of long, thin, bluntly pointed or rounded apically, stout setae and hair-like setae; of terga IV–VII with several elongated rounded or bifurcated apically stout setae near paired projections; of terga VIII–X with rows of elongated or short, stout setae with rounded or bifurcated apices (these rows extending from paired projections to lateral margins). Lateral margins of terga IV–VIII covered with numerous rounded or bifurcated apically stout setae. Posterolateral projections of abdominal segments IV–IX present (Fig.
Pairs of pointed, not bifurcated projections present on abdominal terga II–IX (Fig.
Dorsal surfaces of abdominal gills covered with hair-like setae (mainly in apical part) and scale sockets; shape of gills as in Fig.
Caudal filaments subequal in length, with elongated stout setae with bluntly pointed, bifurcated or pointed apices and hair-like setae at articulations (Fig.
Unknown.
The new species is named in honour of Dr. Shin-ichi Ishiwata (Kanagawa Environmental Research Center, Japan), who contributed significantly to the study of
This new species is close to
Known only from Nepal.
Larvae of
Larva of
Mandibles (Fig.
Larva of
Femora of all legs flattened (length/width ratio = fore femur 2.0–2.1; middle femur 2.0–2.1; hind femur 2.0–2.2), with longitudinal ridges (Fig.
Larva of
Fore femur with distinct transverse band of numerous, mainly extremely long to middle-sized, stout setae with deeply bifurcated apices (some situated on chalazae) (Fig.
Dorsal surfaces of middle and hind femora almost completely covered with different-sized, bifurcated, stout setae, some very long (Fig.
Dorsal surface of all tibiae with longitudinal rows of long, bifurcated stout setae; in middle and hind legs, these rows situated closer to inner margins of tibiae. Outer margin of fore tibia with thin hair-like setae only; in middle and hind tibiae also with regular rows of long, bifurcated, stout setae.
Claws of all legs with one denticle each and several subapical setae (Fig.
Gill III without medial transverse band of weakened membrane, dorsal lobe of gills III–V similar in shape (Fig.
Caudal filaments subequal in length, with pointed, stout setae and hair-like setae on posterior edge of each segment, setae shorter than corresponding segment.
Setae on dorsal surface of thorax of some representatives of
Unknown.
The new species is named in honour of Dr. T.-Q. Wang (formerly Purdue University, USA), who contributed significantly to the study of
Habitats of
This species can be distinguished from other representatives of
India-China border region.
Cold fast-flowing stream with cobbles and gravel. The type locality of
Immature larva: (i) genae moderately developed, rounded; (ii) anteromedian emargination of labrum shallow (labrum height in emargination/maximum labrum height ratio – 0.85); (iii) maxillary palp well-developed; (iv) segment III of maxillary palp, thin, elongated, rounded apically; (v) group of 13–16 setae different-sized, stout, hair-like situated on surface of galea-lacinia near base; (vi) prothoracic anterolateral projections small; (vii) mesothoracic anterolateral projections well-developed, subparallel to lateral aspect of body, not notched; (viii) surface of thorax covered with scattered short, thin, hair-like setae and few scale sockets and very short rounded scales with feathered margins in some of them; few waved and hooked setae cover mainly wing pads; (ix) dorsal surface of fore femur with sparse, transverse row of mainly long, stout setae with slightly convergent margins and bifurcated apices; (x) tarsal claw with one large denticle and several subapical setae; (xi) pairs of pointed projections present on abdominal terga II–IX; those on terga V–VIII strongest; those on tergum IX moderately developed, rounded apically.
Nepal.
Two middle larval instars (body length 5.5–6.5 mm; caudal filaments length 5.2–5.3 mm) of this operational taxonomic unit (OTU) were collected in Nepal in 2014. However, the poor material and absence of late larval instars do not allow us to describe a new species adequately. We hope that this account will facilitate discovery of additional material of this OTU.
Larvae of
To date, nine species of the genus
Overall, only three of all known species of
In light of the several new species described since
Based on our research, we conclude that the establishment of the discussed complexes was for expediency. In fact, the
Distinguishing larval characters of
Characters | ||||
---|---|---|---|---|
1 | Two pairs of suboccipital tubercles | present | absent | absent |
2 | Serration of margins of middle and hind femora | present | absent | absent* |
3 | Presence of numerous large, rounded, scale sockets on body surface | present | absent | present |
4 | Rate of anterolateral emargination of labrum | shallow | from shallow to deep | moderate |
5 | Maxillary palp | reduced, articulations of segments not distinct, especially between segments I and II | mainly well-developed, articulations of all segments distinct** | absent |
6 | Segments I and II of labial palp | wide | wide | relatively narrow, elongated |
7 | Stout setae on outer margin of fore femur | several stout setae only | numerous stout setae | several stout setae only |
8 | Stout setae on dorsal surface of middle and hind femora | absent or up to several stout setae in basal area | surface with numerous stout setae | absent |
9 | Shape of hind femur | strongly or moderately widened | moderately widened | moderately widened |
10 | Stout setae on dorsal surface of abdominal terga and paired projections | absent | present | absent |
The following morphological features place
Systematic structure of
The authors are grateful to Dr. Mikhail V. Chertoprud (Lomonosov Moscow State University, Russia) for donation of larval materials from his collection; to Dr. Arnold H. Staniczek (Stuttgart State Museum of Natural History, Stuttgart, Germany) for the opportunity to investigate the holotype of