The Real Characters of Heptagenia ngi Hsu (1936) from China Representing a New Genus (Ephemeroptera: Heptageniidae)^†

Round 1

Reviewer 1 Report

The manuscript is well written and good organised. However, minor corrections were made by track comments.

Comments for author File: Comments.pdf

Author Response

Response to Reviewer 1 Comments

 

Point 1: The species Heptagenia ngi Hsu,[Hsu 1963] on the contrary, is still in the original genus because of lacking more details and nymph-adult association.

 

Response 1: We have added the naming year ”1936” behind “Hsu,”(page 1 line 32).

 

Point 2: The Heptagenia ngi DNA extraction and amplification were following the process in 50

Zheng＆Zhou (2021)[not the same with Table 1]

 

Response 2: This species name has not been changed at 2021, so its sequence was uploaded with the old name. A new one is updated and uploaded right now and awaiting the approve.

 

Point 3: Generally, the nymphs of the new genus are similar to those of the genera Electrogena and Thamnodontus but with outstanding color pattern.[Please comparison (use Table) the characters of the new genus with related genera i.e. Electrogena, Parafronurus and Thamnodontus for clarification.]

 

Response 3: We skip a long table in our comparison to avoid repeat and redundant. 

 

Point 4: (in contrast to the genera Electrogena and Thamnodontus whose heads have distinct extensions) [italic]

 

Response 4: Those two genera have been italicized in the new version. 

 

Point 5: Figure 7. Adult structures of Maculogenia ngi (digital photos): A. Transverse suture of mesonotum; B. Medial depression of furcasternum (shown in red arrow); C. Foreleg[(shown in red arrow)]

 

Response 5: This picture and related sentence have been improved and changed. The remarks requested are added.

 

Point 6: Egg (Fig. 9): oval, chorion decorated with irregular small tubercle-like projections (Fig. 9A). Small knob-terminated coiled threads (KCTs) densely concentrated on whole surface, micropyle situated equatorially (Fig. 9B).[Please indicate KCTs and micropyle (M) in Figure 9.]

 

Response 6: We have shown arrows to indicate KCTs and micropyle in Figure 9.

 

Point 7: Discussion[Please discuss about why the original species belong to the genus Heptagenia? Which characters support to Heptagenia? And why the authors transferred to new genus (Maculogenia)? Which characters difference form Heptagenia? Please discuss the egg morphology of new genus is related other genera.]

 

Response 7: Hsu (1936) did not presented any reasons to include this species in the genus Heptagenia, another important issue is its nymph was not known at that time.

In the present paper, we stated this point in our introduction, and discussed deeply the reasons it deserves a new genus.

The eggs of Heptageniidae do not vary significantly, most species and genera have similar egg morphology. They have very limited value in taxonomy.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

This is a interesting and potentially important paper. The desciptions and illustrations are fine, all stages being described. Some comments are directly on the manuscript.

My main concern is related to the relationships of the new genus with other members of the Ecdyonurinae.

First, I want the authors to check carefully the structure of the dentisetae. On figure 4A, I have a doubt on the presence of another dentiseta anteriorly. If the dentisetae are properly described, then the new genus cannot belong to Atopopus/fg1, hence is not related to Thamnodontus, Notacanthurus, Thalerosphyrus, Electrogena and Afronurus. Based on two distal dentisetae, it is not related to Nixe, Rhithrogeniella or Paracinygmula. The structure of the dentisetae, the shape of the supracoxal spurs, the size of the first segment of the foretarsi, general shape of the genitalia, indicate this genus is related to Compsoneuria, and therefore could belong to the tribe Compsoneurinii.

Electrogena fracta is probably a member of the new genus, I agree. There are in fact no species of the genus Electrogena in tropical south-east Asia; I would suggest the authors to transfer it.

I think the discussion should be expended in more details concerning these two points.

Comments for author File: Comments.pdf

Author Response

Response to Reviewer 1 Comments

 

Point 1: caudal filaments have spine-like setae and few tiny hair-like setae (in contrast Nixe and Parafronurus).[You have to add Rhithrogeniella here]

 

Response 1: Yes, we added this genus name here.

 

Point 2: The first segment of male foretarsus is only 1/7x second one.[The same in Compsoneuria]

Response 2: Our new genus Maculogenia differentiates from Compsoneuria in both imagos and nymphs. The former genus has no spine on penes, which is almost totally fused together, and normal crossveins of forewings in imagoes. Its nymph has simple scattered setae on maxillary ventral surface. In contrast, the latter genus has spines on penes, somewhat decreased crossveins of forewings, apical penes are divergent in imagoes, its nymphs has fringed hair-like setae on maxillae.  

In short, they are unlike in several characters, which make us do not believe they are close. So we do not compare them point to point in our draft.

 

Point 3:  (4)The mid- and hindtarsi of the new genus are less than 1/2x tibiae, shorter than most other genera, especially Regulaneuria and Thalerosphyrus.[But the same in Compsoneuria]

 

Response 3: Upon response 2, the genus Compsoneuria is not needed here to mention.

 

Point 4:  (5) Cephalic capsule extends slightly forwards (in contrast to the genera Electrogena and Thamnodontus whose heads have distinct extensions)[Italics, I don't understand this character. What are distinct extensions in the head of Electrogena?]

 

Response 4: The generic format has been corrected. The head extension of some heptageniids is a protruded lobe or area of the anterior cephalic margin. Please see the pictures 128, 130-134 in the paper of Webb & McCafferty (2008) (the key to heptageniid genera of the world). 

 

Point 5: In general, this new genus is close to Electrogena and Thamnodontus in nymph but their adults are different because of lacking spines on expanded penes, its head does not extend either.[I find the nymph of the new genus much more similar to Compsoneuria]

 

Response 5: Please see the response 2. Those two genera (Maculogenia, Compsoneuria) are not alike. 

 

Point 6: Materials examined[As the original material is lost, I would find wise to designate a neotype, if possible from the same locality or a nearby area.]

 

Response 6: We have designated a neotype for this species.

 

Point 7: Figure 4 indications

 

Response 7: This picture has been improved, the marks of it have been moved and changed. 

 

Point 8: First, I want the authors to check carefully the structure of the dentisetae. On figure 4A, I have a doubt on the presence of another dentiseta anteriorly. If the dentisetae are properly described, then the new genus cannot belong to Atopopus/fg1, hence is not related to Thamnodontus, Notacanthurus, Thalerosphyrus, Electrogena and Afronurus. Based on two distal dentisetae, it is not related to Nixe, Rhithrogeniella or Paracinygmula. The structure of the dentisetae, the shape of the supracoxal spurs, the size of the first segment of the foretarsi, general shape of the genitalia, indicate this genus is related to Compsoneuria, and therefore could belong to the tribe Compsoneurinii.

Response 8: Yes, it is. We updated and added this in our draft. 

 

Point 9: Electrogena fracta is probably a member of the new genus, I agree. There are in fact no species of the genus Electrogena in tropical south-east Asia; I would suggest the authors to transfer it.

Response 9: Yes, this is very probable. However, we do not want to do this transfer or combination without checking any Taiwan specimen of this species Electrogena fracta. This meaning is also stated in our draft.

 

 

 

 

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Some minor mitakes, especially in the discussion of the generic status

Comments for author File: Comments.pdf

Author Response

Response to Reviewer 2 Comments

Point 1: Crossveins of wings are not reduced (in contrast Compsoneuriia [Compsoneuria] and Regulaneuria).

Response 1: Yes, this is a typo, we’ve corrected it.

 

Point 2: Upon its two independant dentiseate and imaginal characteristics, this genus is a member of the tribe Compsonuriini (Rhithrogeniella, [In my opinion, Rhithrogeniella is not a member of Compsoneurinii] Compsoneuria, Compsoneuriella and Notonurus) sensu Sartori (2014). Except setal pattern of maxillae [Notonurus possesses the same setal structure than your new genus], its nymph is also similar to this tribe.

Response 2: Yes, we removed the genus Rhithrogeniella, and changed the latter sentence to “The nymphal setal patterns on ventral maxillae of two genera Maculogenia and Notonurus are very similar too.”

Author Response File: Author Response.pdf