Cincticostella corpulenta (Braasch, 1981)

Martynov, Alexander V., Selvakumar, C., Palatov, Dmitry M., Subramanian, K. A., Sivaramakrishnan, K. G., Vasanth, M. & Jacobus, Luke M., 2021, Overview of Indian and Nepali representatives of the Cincticostella nigra (Ueno, 1928) complex (Ephemeroptera, Ephemerellidae), with discussion about Cincticostella Allen, 1971 species complexes, ZooKeys 1040, pp. 123-166 : 123

publication ID

https://dx.doi.org/10.3897/zookeys.1040.64280

publication LSID

lsid:zoobank.org:pub:E593F4D8-450E-4D1A-AF0E-1CD2BBB04905

persistent identifier

https://treatment.plazi.org/id/70CE7CD2-C7F0-5185-8E7F-205E22B6D87A

treatment provided by

ZooKeys by Pensoft

scientific name

Cincticostella corpulenta (Braasch, 1981)
status

 

Cincticostella corpulenta (Braasch, 1981) Figs 5 View Figure 5 , 6 View Figure 6 , 7 View Figure 7 , 8 View Figure 8

Ephemerella (Drunella) corpulenta Braasch, 1981

Cincticostella corpulenta (Braasch, 1981) in Jacobus and McCafferty 2008

Remarks.

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 ( Braasch 1981) due to subsequent damage, fading or distortion of the aging specimens.

Description.

Larva (male). Body brown according to Braasch (1981), body length 10 mm; caudal filaments length 6 mm. Head: Without tubercles and ridges. Braasch (1981) described head as elongated [original text in German: Kopf langgestreckt], but in holotype genae, these are poorly developed, therefore head appears oval dorsally (Fig. 5A View Figure 5 ).

Dorsal surface of head covered with numerous very short scales, empty scale sockets and short, hair-like setae. Mouthparts (Fig. 6A-H View Figure 6 ): Labrum wide, angles rounded; anteromedian emargination deep (labrum height in emargination/maximum labrum height ratio - 0.73) (Fig. 6C View Figure 6 ). Anterior margin of labrum mainly with long, stout and thin, hair-like setae; dorsal surface densely covered mainly with long, stout hair-like setae (mainly in apical half), very short scales, empty scale sockets and short hair-like setae.

Mandibles (Fig. 6A, B View Figure 6 ) covered with empty scale sockets, very short scales and long hair-like setae (stout and thin), hair-like setae most numerous near outer margins and central parts of surfaces; both prosthecae consisting of protuberance with tuft of middle-sized hair-like setae. Planate mandible with row of six long, stout hair-like setae under mola and tuft of short hair-like setae above; outer incisor with three teeth; inner incisor (kinetodontium) bifurcated. Outer incisor of angulate mandible apex with four teeth; inner incisor with three teeth (two central ones distinctly larger). Superlinguae with rounded apices covered with long, stout hair-like setae (Fig. 6D View Figure 6 ); lingua with shorter setae. Lingua surface near base with transverse row of six short, pointed, stout setae. Maxilla (Fig. 6F View Figure 6 ) with two dentisetae with inner margins serrate. Apex and apical part of maxilla surfaces with numerous long, stout, hair-like setae; galea-lacinia with numerous, long, stout, hair-like setae on inner margin. Group (26, 29) of different-sized, stout, hair-like setae (some very long), situated on surface of galea-lacinia near base. Maxillary palp long, 3-segmented; joins between segments distinct (Fig. 6E View Figure 6 ). Segments I and II with long, hair-like setae, most strong setae situated on segment I; segment III slightly elongated and rounded apically. Glossae rounded; dorsal surfaces covered with short and middle-sized, stout, hair-like setae. Apices of paraglossae densely covered with mostly long and middle-sized, stout, hair-like setae; ventral surface of labium densely covered with mostly long, stout, hair-like setae (Fig. 6H View Figure 6 ). Labial palp 3-segmented (Fig. 6G View Figure 6 ); segment I and II distinctly flattened and subequal in length; ventral sides densely covered with long, hair-like setae (stout and thin); dorsal surfaces with long, stout, hair-like setae along outer and inner margins; central part of segment I dorsal surface also densely covered with scale sockets and very short rounded scales with feathered margins in some sockets. Segment III distinctly elongated (length/width ratio = 3.40-4.15), rounded apically, with short, fine setae mainly at apex. Submentum with scattered long, stout, hair-like setae, very short rounded scales with feathered margins in some sockets and empty scale sockets.

Thorax: Dorsal surface of thorax covered with scattered short, waved and hooked, stout hair-like setae, thin and stout, hair-like setae and scale sockets (Fig. 23B View Figure 23 ); most distinct waved and hooked setae on veins of fore wing pads. Pronotum with moderately convex, rounded and broad anterolateral angles (Fig. 5C-E View Figure 5 ). Anterolateral projections of mesothorax poorly developed, rounded and not notched, with margins not subparallel to lateral aspect of body (Fig. 5B, C View Figure 5 ). Thoracic surface without distinct ridges and tubercles. Two blunt posterior projections present between fore wing pads; cleft between projections wide; apical parts of outer margins of projections pressed against wing pads.

Legs slightly flattened (length/width ratio = fore femur 2.08; hind femur 2.56), each one with longitudinal ridge (Fig. 7A, B View Figure 7 ). Average length ratio of leg’s parts (femora: tibia: tarsi): foreleg 1.95: 1.68: 1; hind leg 2.59: 2.38: 1. Outer margins and proximal parts of dorsal surfaces of femora covered with irregular row of different-sized, stout setae with mostly rounded or bifurcated apices (Fig. 7A, B, E View Figure 7 ). Basal half of inner margin of fore femur and adjacent part of dorsal surface densely covered with spine-like setae and long, stout, hair-like setae. Apical half of dorsal surface of fore femur with transverse, sparse, band of mainly middle-sized and long, stout setae with bifurcated or rounded apices (some setae situated on chalazae) (Fig. 7A, C View Figure 7 ); several elongated, pointed or bifurcated apically, stout setae with feathered margins situated on dorsal surface near basal margin. Additionally, whole dorsal surface of fore femur covered with very short, rounded scales with feathered margins, empty scale sockets and different-sized hair-like setae. Inner margin and adjacent part of dorsal surface of fore tibia with numerous long, stout, hair-like setae and few, thin, hair-like setae (solitary and in tufts); another part of dorsal surface of fore tibia with row of long, bifurcated apically, stout setae and scattered hair-like setae (solitary and in tufts). Inner parts of ventral and dorsal surfaces of fore tibia and tarsus with numerous long, stout, hair-like setae (some with feathered margins in apical part); additionally, whole ventral and dorsal surfaces of fore tibia and tarsus with scattered hair-like setae (solitary and in tufts). Outer margins of fore tibia and tarsus with only long, hair-like setae. Outer margin of hind femur without apical projection; whole margin and part of dorsal surface covered with different-sized, stout setae with rounded and bifurcated apices. Whole dorsal surface covered with numerous short, rounded and bifurcated, stout setae, scale sockets, short scales with feathered margins in some sockets and scattered short, sometimes waved, stout, hair-like setae. Inner margin of hind femora with only solitary thin, hair-like setae. Outer margin of hind tibia with regular row of long, stout setae with pointed and bifurcated apices and scattered hair-like setae (Fig. 7B, E View Figure 7 ). Dorsal surface of hind tibia with irregular row of long, stout setae with bifurcated apices, situated along inner margin (Fig. 7D View Figure 7 ); whole surface covered with scattered long hair-like setae (solitary and in tufts) and short, stout, hair-like setae (some apparently waved or hooked). Inner margins and ventral surfaces of hind tibia and tarsus as in fore leg.

Tarsal claws of all legs hooked, with one large denticle and several subapical setae (Fig. 7F View Figure 7 ).

Abdomen: Central part of dorsal surface of terga II-IX with two medial fields of mainly short stout setae with rounded or bluntly pointed, sometimes bifurcated, apices (Fig. 8A-C View Figure 8 ). Surfaces of all terga covered with not numerous hair-like setae (mainly stout, waved of hooked), empty scale sockets and very short rounded scales with feathered margins (most scales and sockets situated laterally). Whole sternal surfaces covered with scattered empty scale sockets, scales and hair-like setae. Posterior margins of tergum I with row of mostly long, hair-like setae; posterior margins of terga II-III (especially tergum II) with row of elongated, mostly bluntly pointed and bifurcated apically, stout setae and stout, hair-like setae; posterior margins of terga IV-VII with several elongated mostly rounded and bluntly pointed apically, stout setae, extending from paired projections to lateral margins; posterior margins of terga VIII-X with rows of elongated stout setae with mostly rounded apices (rows extending from paired projections to lateral margins) (Fig. 8B-E View Figure 8 ). Lateral margins of terga IV-VIII covered with rounded apically stout setae most numerous.

Pairs of not bifurcated projections present on abdominal terga II-IX, relatively weakly developed (Fig. 8A-E View Figure 8 ). Projections on terga VI-VIII strongest; those on terga II and III smallest and rounded; those on tergum IV elongated and bluntly pointed; those on terga V-VIII pointed; those on tergum IX short and bluntly pointed. Posterior margin of tergum X smooth, without any projections (Fig. 8E View Figure 8 ). Surfaces of paired projections on terga II-IX with several mostly short, stout setae with rounded apices.

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. 8F View Figure 8 ) at articulations and hair-like setae (solitary and in tufts) on surfaces of segments.

Diagnosis.

This species can be distinguished from all other species of the C. nigra complex by the following combination of characters: (i) genae poorly developed, head oval dorsally (Fig. 5A View Figure 5 ); (ii) labrum with deep anteromedian emargination (Fig. 6C View Figure 6 ); (iii) maxillary palp well-developed (Fig. 6E View Figure 6 ); (iv) segment III of maxillary palp small, rounded apically (Fig. 6E View Figure 6 ); (v) prothoracic anterolateral projections rounded and broad (Fig. 5C-E View Figure 5 ); (vi) mesothoracic anterolateral projections poorly developed, rounded, not notched, with margins not subparallel to lateral aspect of body (Fig. 5B View Figure 5 ); (vii) short, waved and hooked, stout hair-like setae presented on dorsal surface of thorax (Fig. 23B View Figure 23 ); (viii) dorsal surface of fore femur with transverse, sparse, band of mainly middle-sized and long, stout setae with bifurcated or rounded apices (Fig. 7A and C View Figure 7 ); (ix) tarsal claw with one large denticle (Fig. 7F View Figure 7 ); (x) pairs of pointed, relatively weakly developed, projections present on abdominal terga II-IX; those on terga II and III smallest and rounded; those on terga VI-VIII strongest; those on terga V-VIII pointed; those on tergum IX short and bluntly pointed; posterior margin of tergum X smooth, without any projections (Fig. 8A-E View Figure 8 ).

Distribution.

Nepal ( Braasch 1981).

Remarks.

Adult stages unknown. The holotype (on slide) has the middle legs and one hind leg missing.

Habitat.

No data, but assumed to be cold water rivers and streams, based on what we know about the Trisuli River near Dhunche.

Type material examined.

Holotype: Nepal: larva on slide, Himalaya, Trisuli Khola vor Dhunche, 1950 m a.s.l. NN, 30.04.1978, Leg. I. Sivec [SSMNH]. Paratypes: two larvae, same data as holotype [PERC].