Research Article |
Corresponding author: Viktor Baranov ( viktor.baranov@ebd.csic.es ) Academic editor: Fabio Laurindo da Silva
© 2024 Trond Andersen, Galileu P. S. Dantas, Viktor Baranov, Annui M. Sanz-laParra, Humberto F. Mendes, Neusa Hamada.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Andersen T, Dantas GPS, Baranov V, Sanz-laParra AM, Mendes HF, Hamada N (2024) Poxyaibamberus Andersen & Dantas, gen. nov. (Diptera, Chironomidae, Orthocladiinae) from Brazil. ZooKeys 1205: 1-15. https://doi.org/10.3897/zookeys.1205.124081
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Poxyaibamberus Andersen & Dantas, gen. nov. is erected based on the males of two species, P. jamanximensis Andersen & Dantas, sp. nov. from Jamanxim National Park, Pará State, Brazil, and P. ubajarensis Andersen & Dantas, sp. nov. from Ubajara National Park, Ceará State, Brazil. Both species have a comparatively short and wide head, with large eyes and short, five-segmented palps; a strong subapical seta on the ultimate flagellomere; scalpellate acrostichals; no setae on the wing veins except for one seta on the brachiolum; a long costal extension; and a large triangular anal point and a very long heel on the gonostylus. The systematic position of the new genus is briefly discussed.
Aquatic insects, new species, Neotropical Region, taxonomy
The number of orthoclad species known from Brazil has increased rapidly during the last three decades. In their catalog of the Neotropical and Mexican chironomids
Below we describe a new genus based on the males of two new species collected in Pará and Ceará states in northern and northeastern Brazil. Both species have a comparatively wide head with large eyes and short, five-segmented palps, a strong subapical seta on the ultimate flagellomere, scalpellate acrostichals, a long costal extension, no setae on the wing membrane and veins except for one seta on the brachiolum, a large triangular anal point, and a gonostylus with a very long heel. The systematic position of the new genus is briefly discussed.
The specimens were collected with Shannon traps (
For the phylogenetic analysis we have used a morphological character matrix with 45 taxa and 83 characters. Characters were sampled from larvae, pupae, and adult males and females. Fossils were of course underrepresented in terms of characters available for observation (see https://github.com/chironomus/Poxyaibamberus-). The character matrix for the phylogenetic analysis was built using NEXUS DATA EDITOR v. 0.5. 0 (
First, a Bayesian analysis of the morphological matrix alone in MRBAYES 3.2.2. (
To deal with the uncertainty of the positions of the genus on the tree caused by the lack of knowledge of character states, the Klopfstein and Spasojevic ROGUEPLOTS approach was applied (
Both holotypes are kept in the Invertebrate collection at the Instituto Nacional de Pesquisas da Amazônia (INPA), Manaus, Brazil.
Family Chironomidae Newman, 1834
Subfamily Orthocladiinae Kieffer, 1911
Poxyaibamberus jamanximensis Andersen & Dantas, sp. nov.
Small species, wing length 1.1–1.3 mm.
Male antenna with 13 flagellomeres, strongly plumose, groove beginning on flagellomere 4, few sensilla chaetica apparently only present on flagellomere 13, with strong subapical seta. Antennal ratio 0.9.
Head short and wide. Eye bare, large, reniform, without dorsomedian extension. Temporal setae in single row, consisting of inner and outer verticals. Frontal tubercle absent. Tentorium and stipes normal. Clypeus with few setae. Palp short, with 5 segments, third palpomere without sensilla clavata subapically.
Thorax. Antepronotum well developed, with lobes meeting medially at anterior margin of scutum, with few ventrolateral antepronotals. Acrostichals small, scalpellate, in two rows starting some distance from antepronotum; dorsocentrals simple, uniserial; prealars few; supraalar absent. Scutellum apparently without setae.
Wing. Membrane without setae, with fine punctuation. Anal lobe reduced. With long costal extension. R2+3 running and ending close to R4+5; R4+5 ending distal to M3+4; FCu far distal to RM; Cu1 curved. Brachiolum with 1 seta, other veins bare. Squama bare. Sensilla campaniformia 3 above seta on brachiolum.
Legs. Tibial spurs normal, comb with few setae. Pseudospurs and sensilla chaetica absent, pulvilli vestigial.
Abdomen. Tergites with few setae, mostly in anterior band; sternites with few setae.
Hypopygium. Anal point long, triangular, with microtrichia, with or without strong setae at base, originating high on tergite IX or at posterior margin. Tergite IX with or without setae; laterosternite IX with few setae. Phallapodeme with aedeagal lobe well developed. Transverse sternapodeme arched or straight, without oral projections. Virga apparently consists of small spines. Gonocoxite long, without volsellae. Gonostylus without crista dorsalis, with long, weakly to strongly curved heel; megaseta normal.
From Tupi Poxyaiba, ugly and Mberu, fly, meaning “the ugly fly”, referring to the spiny hypopygium of P. jamanximensis Andersen & Dantas, sp. nov. with a very large anal point. The name is masculine.
Brazil, Pará State, Itaituba, Jamanxim National Park; 05°41'58"S, 55°48'13"W; 170 m a.s.l.; 20 November 2017; Gilberto Nicácio leg.
Holotype male adult, slide-mounted in Euparal under six coverslips. Original label: “Brasil, PA, 20/11/2017, Floresta # 41, Shannon trap, Orthocladiinae, leg. G. Nicasio, ♂”. (INPA).
The new species can easily be separated from P. ubajarensis Andersen & Dantas, sp. nov. by the shape of the gonostylus, as it has a rather narrow, weakly curved, tapering heel that is slightly longer than the gonostylus proper.
Adult male (n = 1). Total length 2.17 mm. Wing length 1.23 mm. Total length / wing length 1.77. Wing length / length of profemur 2.51.
Coloration. Head, thorax, and legs light yellowish brown; abdomen pale yellowish brown. Wing hyaline.
Antenna
(Fig.
Head
(Fig.
Thorax. Antepronotum with 2 ventrolateral setae. Acrostichals about 8, scalpellate, in double row starting some distance from antepronotum; dorsocentrals 8, uniserial; prealars 3. Scutellum apparently without setae.
Wing
(Fig.
Legs. Fore tibia with 33 µm long spur, mid tibia with 28 and 15 µm long spurs, hind tibia with 45 and 21 µm long spurs. Width at apex of fore tibia 27 µm, of mid tibia 28 µm, of hind tibia 29 µm. Hind tibia with comb of 4 bristles, longest apparently about 28 µm long. Lengths and proportions of legs as in Table
Lengths (in µm) and proportions of legs of Poxyaibamberus jamanximensis Andersen & Dantas, sp. nov., male (n = 1).
Fe | Ti | ta1 | ta2 | ta3 | ta4 | ta5 | LR | BV | SV | BR | |
---|---|---|---|---|---|---|---|---|---|---|---|
P1 | 490 | 596 | 547 | 270 | 155 | 82 | 49 | 0.918 | 2.941 | 1.985 | 2.10 |
P2 | 564 | 572 | 343 | 172 | 98 | 49 | 33 | 0.600 | 4.209 | 3.310 | 2.30 |
P3 | 605 | 629 | 417 | 212 | 163 | 82 | 41 | 0.662 | 3.311 | 2.961 | 2.40 |
Hypopygium
(Fig.
Immatures and female. Larva, pupa, and female are unknown.
The epithet, jamanximensis, is used as an adjective and meaning “from Jamanxim” in reference to the place of origin of the holotype.
The species is only known from the type locality in Jamanxim National Park, Pará State, in northern Brazil, where it was collected in a Shannon trap placed near a lower-order stream. Only a single male was collected despite intensive sampling effort during the expedition with successive sampling using several types of traps. According to data from the National Institute for Space Research, the Jamanxim National Park ranks among the conservation units with the highest deforestation rates in the Amazon. This situation underscores the need to increase the knowledge of the biodiversity in this region to better understand the anthropogenic impacts on the biota and to utilize this knowledge as tools for developing conservation strategies. The discovery of a new genus of Chironomidae in the park highlights the importance of further research to understand and preserve its unique biodiversity.
Brazil, Ceará State, Ubajara, Ubajara National Park, Cafundó waterfall, 03°50'13"S, 40°54'35"W, 805 m a.s.l., 25–26 February 2023, N. Hamada, J. Silva, J.M.C. Nascimento, G.P. Amorim Jr. leg.
Holotype male adult, slide-mounted in Euparal under five coverslips. Original label: “Brasil, CE, Ubajara, Parque Nacional de Ubajara, Cachoeira do Cafundó, 25-26/02/2023, light-trap, N. Hamada” (INPA).
The new species can easily be separated from P. jamanximensis Andersen & Dantas, sp. nov. on the shape of the gonostylus, as it has a rather broad, curved, tapering heel that is slightly shorter than the gonostylus proper.
Adult male (n = 1). Total length 2.02 mm. Wing length 1.13 mm. Total length / wing length 1.70. Wing length / length of profemur 2.38.
Coloration. Head, thorax, and legs light brown; abdomen pale brown. Wing hyaline.
Antenna. Antenna broken. With 44 µm long subapical setae.
Head. Inner verticals 5, outer verticals 3, postorbitals not discernable. Clypeus with 5 setae. Tentorium 90 µm long, 13 µm wide. Stipes not discernable. Anterior margin of cibarial pump slightly concave. Palp (Fig.
Thorax
(Fig.
Wing. VR = 1.33. Brachiolum with 1 seta, other veins and membrane bare. Squama bare. Costal extension 113 µm long.
Legs. Fore tibia (Fig.
Lengths (in µm) and proportions of legs of Poxyaibamberus ubajarensis Andersen & Dantas, sp. nov., male (n = 1).
Fe | Ti | ta1 | ta2 | ta3 | ta4 | ta5 | LR | BV | SV | BR | |
---|---|---|---|---|---|---|---|---|---|---|---|
P1 | 474 | 507 | – | – | – | – | – | – | – | – | – |
P2 | 507 | 515 | 310 | 155 | 98 | 53 | 45 | 0.602 | 3.795 | 3.297 | 1.92 |
P3 | 605 | 629 | – | – | – | – | – | – | – | – | – |
Hypopygium
(Fig.
Immatures and female. Larva, pupa, and female are unknown.
The epithet, ubajarensis, is used as an adjective and meaning “from Ubajara” in reference to the place of origin of the holotype.
The species is known only from the type locality in the Ubajara National Park in northeastern Brazil. The park covers an area of 6.288 ha and receives abundant rainfall, averaging 1.400 mm annually, while temperatures typically range between 22 °C and 26 °C. The vegetation in the park is characterized by its high diversity, with higher elevations adorned by lush humid forests (
In a consensus tree produced in the Bayesian analysis neighboring search, Poxyaibamberus falls out with Mesosmittia Brundin, 1956, Pseudosmittia Goetghebuer, 1932, Eretmoptera Kellog, 1900, Thalassosmittia Strenzke & Remmert, 1957, and Petalocladius Sublette & Wirth, 1972 (Fig.
Position of Poxyaibamberus Andersen & Dantas, gen. nov. (marked in red) in the phylogenetic tree of Orthocladiinae, reconstructed with Bayesian inference (all posterior probabilities of the nodes are displayed, regardless of the value). This is a majority-rule consensus tree based on morphology only.
When posterior position probability mapping (“Rogue plots”) was applied, Poxyaibamberus was plotted in approximately 20% of the cases next to Stictocladius Edwards, 1931 and in approximately 20% of the cases next to Pseudosmittia / Eretmoptera (Fig.
We are indebted to Jeane M.C. Nascimento, Jeferson O. da Silva, and Gilson P. Amorim Jr. for their invaluable support during the fieldwork in the Ubajara National Park, and to Gilberto Nicácio for providing us with the male from the Jamanxim National Park. NH received a CNPq research fellowship (process 308970/2019-5). GPSD is granted a postdoctoral fellowship by FAPEAM (process 01.02.016301.03271/2021-93). The following projects provided partial financial support: Sistemática integrada de insetos aquáticos na América do Sul (CNPq and Instituto Nacional de Pesquisas da Amazônia-INPA), and INCT ADAPTA II funded by CNPq (465540/2014–7) and FAPEAM (0621187/2017). Collection in Ubajara National Park was made under the SISBIO permit no. 82848-1. The University Museum of Bergen provided office space, microscope, and other equipment for TA.
The authors have declared that no competing interests exist.
No ethical statement was reported.
V. Baranov’s work is also funded by the State Agency of Innovation, within the Ramon y Cajal Program, grant number RYC2021-032144-I. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Vktor Baranov received funds supporting the payment of this publication fees through the CSIC Open Access Publication Support Initiative from the CSIC Unit of Information Resources for Research (URICI). CNPq research fellowship (Process 308970/2019-5) to N. Hamada. FAPEAM postdoctoral fellowship (Process 01.02.016301.03271/2021-93) to GPSD. CNPq and Instituto Nacional de Pesquisas da Amazônia-INPA funded the project “Sistemática integrada de insetos aquáticos na América do Sul”. CNPq (465540/2014–7) and FAPEAM (0621187/2017) funded the project “INCT ADAPTA II”. University Museum of Bergen, Bergen, Norway.
Trond Andersen – describing the new taxa, drawing the figures, preparation of manuscript, review of manuscript. Galileu P.S. Dantas – sorting and slide preparations, identification of specimens, preparation of manuscript. Viktor Baranov – phylogenetic analysis. Annui M. Sanz-laParra – photo, preparation of manuscript, review of manuscript. Humberto F. Mendes – preparation of manuscript. Neusa Hamada – organizing fieldwork, review of manuscript.
Trond Andersen https://orcid.org/0000-0003-2201-1870
Galileu P. S. Dantas https://orcid.org/0000-0002-9155-533X
Viktor Baranov https://orcid.org/0000-0003-1893-3215
Annui M. Sanz-laParra https://orcid.org/0000-0003-0580-6890
Humberto F. Mendes https://orcid.org/0000-0002-8261-3665
Neusa Hamada https://orcid.org/0000-0002-3526-5426
All of the data that support the findings of this study are available in the main text or in https://github.com/chironomus/Poxyaibamberus-.