Research Article |
Corresponding author: Atilano Contreras-Ramos ( acontreras@ib.unam.mx ) Academic editor: Ernesto Rázuri-Gonzales
© 2022 Alba Magali Luna-Luna, Caleb Califre Martins, Andrés López-Pérez, Andrés Ramírez-Ponce, Atilano Contreras-Ramos.
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:
Luna-Luna AM, Martins CC, López-Pérez A, Ramírez-Ponce A, Contreras-Ramos A (2022) Aquatic beetle diversity from Volcán Tacaná, Mexico: altitudinal distribution pattern and biogeographical affinity of the fauna. In: Pauls SU, Thomson R, Rázuri-Gonzales E (Eds) Special Issue in Honor of Ralph W. Holzenthal for a Lifelong Contribution to Trichoptera Systematics. ZooKeys 1111: 301-338. https://doi.org/10.3897/zookeys.1111.68665
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Results of an aquatic beetle survey at Volcán Tacaná, Mexico, are presented with five altitudinal levels in a monthly sampling regime, aiming to estimate both diversity and altitudinal distribution patterns of the aquatic beetle fauna. The first list of aquatic beetle species from this mountain is presented, comprising 40 species in 32 genera and nine families, with four species recorded for the first time from Mexico and six recorded for the first time from Chiapas. The aquatic beetle fauna is characterized by Elmidae with 20 species, Dytiscidae with eleven species, Dryopidae with three, and Epimetopidae, Hydraenidae, Hydrophilidae, Gyrinidae, Lutrochidae, and Noteridae with one species each. The species composition through the sampled altitudinal gradient (670–1,776 m) was not homogeneous, with the elmid genera Macrelmis, Heterelmis, Microcylloepus, and Austrolimnius present at all levels, while Hexanchorus, Neoelmis, and Onychelmis were present at levels 1–3 (673–1,214 m); dytiscids were mostly present at levels 4 and 5 (1,619–1,776 m), and dryopids were present only at levels 1–3. A Parsimony Analysis of Endemicity supports a general partition between altitudinal levels 1–3 and levels 4 + 5.
Aquatic Coleoptera, Central American Nucleus, Chiapas, faunistics, PAE
Among the aquatic insects, aquatic beetles (Coleoptera) are one of the largest groups, with ca. 13,000 described species distributed in 30 families in three of the four coleopteran suborders (
Previous studies in the Neotropics have found that altitude may have a significant influence on the composition and structure of an aquatic insect community, as some genera may show a wide range of distribution, while others are characteristic of a particular altitudinal level (e.g.,
Approximately 583 species of aquatic Coleoptera are known from Mexico (
The Tacaná volcano, in the southern Mexican state of Chiapas and bordering Guatemala, is a key element of Volcán Tacaná Biosphere Reserve, a protected area relevant for its rich biotic, cultural, and economic value. This reserve is at the northernmost range of the Central American Nucleus or Central American Volcanic Arc and lies within the Mesoamerican Biological Corridor (CONANP 2013), a dynamic biogeographical area resulting from the assembly of biotas of Nearctic and Neotropical origin. Understanding the geographical distribution and the local diversity of aquatic insects is important to assess the patterns and processes of biological diversification (
Aquatic entomology, taxonomy, biodiversity, and tropical ecosystems might be a few defining keywords in Ralph Holzenthal’s philosophy as an academic advisor. These are relevant themes of encouragement for descriptive taxonomy and biodiversity exploration through several years of competing fields of knowledge, such as morphological and molecular approaches to systematics, which in the end are sides of the same disciplinary coin. This contribution is proudly dedicated by ACR, after 25 years of graduation, to Ralph’s bright academic career, in the company of young colleagues and AMLL, currently a graduate student and future academic grandchild.
The Tacaná volcano, with its summit at 4,092 m asl, is located in southeastern Chiapas state, Mexico, 30 km NE of Tapachula, with its NE half lying in Guatemala. It is part of the Sierra Madre de Chiapas and lies within the Volcán Tacaná Biosphere Reserve, recognized by UNESCO since 2006. This reserve is located in the Chiapas coast hydrological region (RH-23), on the Pacific slope, and includes the basins of the Suchiate, Coatán, Cahoacán, and Cosalapa rivers (
Five sampling localities were established, each at an altitude level along the volcano (levels 1–5; Figs
Distribution of aquatic beetle species (Coleoptera) in the sampling levels and sites of Volcán Tacaná, Chiapas, Mexico. 0 = absent; 1 = present. Nea = Neartic; Neo = Neotropical.
FAMILY | SPECIES | SAMPLING POINTS | BIOG. REGIONS | |||||||
---|---|---|---|---|---|---|---|---|---|---|
Lv1 | Lv2 | Lv3 | Lv4 | Lv5 | ||||||
R1 | R1 | R1 | R2 | R1 | R2 | R1 | R2 | |||
Dryopidae | 1.Dryops mexicanus | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | Neo. |
2.Elmoparnus pandus | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | Neo. | |
3.Helichus suturalis | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | Nea.; Neo. | |
Dytiscidae | 4.Bidessonotus championi | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | Neo. |
5.Clarkhydrus sp. | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 0 | Neo | |
6.Copelatus distinctus | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | Nea.; Neo. | |
7.Ilybiosoma flohrianum | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 1 | Neo. | |
8.Laccophilus proximus | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 0 | Nea.; Neo. | |
9.Liodessus affinis | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | Nea.; Neo. | |
10.Neoclypeodytes fryii | 0 | 0 | 0 | 0 | 1 | 1 | 0 | 0 | Nea.; Neo. | |
11.Platambus americanus | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | Neo. | |
12.Rhantus gutticollis | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | Nea.; Neo. | |
13.Thermonectus nigrofasciatus | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | Nea.; Neo. | |
14.Uvarus subornatus | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | Neo. | |
Elmidae | 15.Austrolimnius formosus | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | Neo. |
16.Austrolimnius sulcicollis | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | Neo. | |
17.Cylloepus atys | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | Neo. | |
18.Heterelmis glabra | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | Nea.; Neo. | |
19.Heterelmis obesa | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | Nea.; Neo. | |
20.Heterelmis obscura | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | Nea.; Neo.l | |
21.Heterelmis simplex | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | Neo. | |
22.Hexacylloepus metapa | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | Neo. | |
23.Hexanchorus usitatus | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | Neo. | |
24.Huleechius spinipes | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | Nea.; Neo. | |
25.Macrelmis graniger | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | Neo. | |
26.Macrelmis leonilae | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | Neo. | |
27.Macrelmis sp. | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | Neo. | |
28.Microcylloepus inaequalis | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | Neo. | |
29.Microcylloepus troilus | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 1 | Neo. | |
30.Microcylloepus sp. | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | Neo. | |
31.Neoelmis apicalis | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | Nea.; Neo. | |
32.Onychelmis longicollis | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | Neo. | |
33.Phanocerus clavicornis | 1 | 0 | 1 | 1 | 1 | 1 | 0 | 0 | Nea.; Neo. | |
34.Xenelmis bufo | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | Neo. | |
Epimetopidae | 35.Epimetopus thermarum | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | Nea.; Neo. |
Gyrinidae | 36.Gyretes boucardi | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | Neo. |
Hydraenidae | 37.Hydraena sp. | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | Neo. |
Hydrophilidae | 38.Tropisternus fuscitarsis | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | Nea.; Neo. |
Luthrochidae | 39.Lutrochus sp. | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | Neo. |
Noteridae | 40.Notomicrus sharpi | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | Nea.; Neo. |
Level 1. Finca Alianza, municipality of Cacahoatán. The vegetation is evergreen tropical forest. The Cahoacán river (R1) belongs to the Cahoacán basin. The sampling site (15°02.429'N, 92°10.199'W) is located at 673 m asl.
Level 2. Finca Monte Perla, municipality of Unión Juárez. The vegetation is cloud forest. The river Cascada Monte Perla (R1) belongs to the Suchiate basin. The sampling site (15°02.870'N, 92°05.305'W) is located at 998 m asl.
Level 3. Ejido El Águila, municipality of Cacahoatán. The vegetation is cloud forest. On this locality, two rivers were sampled. The first river, La Resbaladilla (R1), belongs to the Cahotán basin, and the sampling site (15°05.564'N, 92°10.849'W) is at 1,214 m asl. The second river, Cascada La Sirena (R2), belongs to the Coatán basin, and the sampling site (15°06.160'N, 92°11.001'W) is located at 1,150 m asl.
Level 4. Ejido Benito Juárez El Plan, municipality of Cacahoatán. The vegetation is cloud forest. On this locality, two rivers were sampled, both belong to the Cahoacán basin. The first river, El Arroyo (R1), has its sampling site (15°05.946'N, 92°08.540'W) at 1,619 m asl. The second river, La Cascada (R2), has its sampling site (15°05.911'N, 92°08.396'W) at 1,741 m asl.
Level 5. Cantón San Isidro, municipality of Unión Juárez. The vegetation is pine forest. Two rivers were surveyed, both belong to the Suchiate basin. The first river (R1) has its sampling site (15°05.611'N, 92° 05.644'W) at an altitude of 1,763 m asl. The second river (R2) has its sampling site (15°05.588'N, 92°05.537'W) at 1,776 m asl.
The aquatic beetles were sampled monthly over a year (February 2018–February 2019). In each water body (sampling site) three points were selected, separated by 30 m from each other. Samples were obtained using a D-type benthos net (500 µm mesh), with a dimension of 30.5 cm wide × 53.3 cm long). A second trapping technique, a bucket black-light trap, was used for 3 hours at each sampling site. Captured specimens with organic matter surplus were stored in zippered plastic bags with 80% ethyl alcohol, which was replaced with clean alcohol after 24 hours; aquatic beetles were then sorted from other insect groups in the laboratory using a dissecting microscope, and subsequently identified.
The aquatic beetle specimens were dissected and identified to species using features of the genitalic structures; individual genitalia were extracted and stored in microvials with glycerin. Specimens were mounted on entomological pins, together with their associated labels and genitalia; specimens smaller than 12 mm were placed in paper cartons (points).
Identification was performed through introductory genus-level keys (
All the material examined was deposited in the Colección Nacional de Insectos (CNIN) of the Instituto de Biología, Universidad Nacional Autónoma de Mexico.
To aid unravel a general distribution pattern of the aquatic beetle fauna along the altitudinal gradient in the volcano, we performed a Parsimony Analysis of Endemicity (PAE). According to
Two analyses were applied: one with the main five levels of sampling (localities) as terminals (i.e., levels 3–5 had sites fused in a single unit), and a second with all eight sampling sites as distribution units or terminals (Table
The matrices (Table
Mapping of the study site with the sampling sites was done with ArcGIS version 10.2. 2. Layers of states and municipalities were obtained from the National Institute of Statistics and Geography (>INEGI), with information on a 1:50,000 scale. Projection of localities with geographical coordinates was carried out with Universal Transverse Mercator (UTM). The raster of the CEM model of the Chiapas area was obtained, a cut of municipalities within the study area was made, with the help of a vector layer of municipal boundaries. The elevation model was adjusted with a reclassification of the z (altitude) values so altitude differences within our area of interest could be visualized. Seven intervals from 0 m to 4080 m were used for the reclassification. In addition, a shadow map (hillshade) was made to better visualize slopes of the terrain of the study area. Finally, layers of the watersheds are located on a scale of 1:50,000, which belongs to the Costa de Chiapas hydrographic region (key RH23).
In total, 23,295 specimens of aquatic beetles of 40 species, distributed in 32 genera and nine families (Dryopidae, Dytiscidae, Elmidae, Epimetopidae, Hydraenidae, Hydrophilidae, Gyrinidae, Lutrochidae, and Noteridae), were collected (Appendix
We record the following four species from Mexico for the first time (Appendix
Entries are arranged alphabetically by family and genus. Entries for genera include comments on number of species, and distribution. Species entries include the valid combination, distributional and altitudinal information, as well as type of substrate where they were collected. Altitude or elevation data are given in m above sea level.
Dryops mexicanus Sharp, 1882
Dryops has a worldwide distribution and comprises 79 species (
Mexico (Chiapas, Morelos), Belize, Costa Rica (
Collected on substrates consisting of gravel, macrophytes, and leaf packs; found in all sampling months (February 2018 through February 2019, dry and rainy seasons); also collected with a bucket light trap.
This genus includes eight species recorded in the Neotropics (
Mexico (Chiapas, Oaxaca), Belize, Guatemala, Honduras, Costa Rica, Panama (
Collected on substrates of gravel, macrophytes, and leaf packs (June 2018, rainy season).
This genus is found throughout the Oriental, Nearctic, and Neotropical regions, with 32 species described (
United States, Mexico (Chiapas, Durango, Hidalgo), Guatemala, Paraguay (
Collected on substrates of gravel, macrophytes, and leaf packs, throughout the sampling period (February 2018 through February 2019, dry and rainy season).
This is one of the largest dytiscid genera in the New World, comprising 36 species (
Mexico (new country record, Chiapas), Guatemala, Honduras, Nicaragua, Costa Rica (
Collected on macrophytes (February 2018, dry season).
This genus has a Nearctic and Neotropical distribution and comprises 10 species, seven of which have been recorded in Mexico (
This species was collected at levels 4 (rivers 1 and 2, 1,448–1,619 m) and 5 (river 1, 1,763 m) on substrates of macrophytes and leaf packs, and was present throughout sampling months (February 2018 through February 2019, dry and rainy season). Specimens did not match known described species of the genus; however, they are close to C. decemsignatus, yet male genital morphology differs.
This genus has a cosmopolitan distribution and comprises 454 species (
United States, Mexico (Baja California, Chiapas, Guanajuato, Jalisco, Morelos, Oaxaca, Puebla, Sonora), Guatemala (
Collected on substrates of macrophytes and leaf packs, through all months of sampling (February 2018 through February 2019, dry and rainy season); also collected with a bucket light trap.
This is a cosmopolitan genus that includes 17 species (Nilsson and Hákej 2020), five of them recorded in Mexico (
Mexico (Estado de México; Chiapas, new state record; Morelos) (
Specimens were found on leaf packs (May 2018, rainy season).
This cosmopolitan genus is the largest of the subfamily Laccophilinae, with 285 species (Nilsson and Hákej 2020), 26 of which are recorded from Mexico (
United States, Mexico (Campeche, Chiapas, Coahuila, Oaxaca, San Luis Potosí, Tabasco, Tamaulipas, Yucatán, Veracruz), Belize, Guatemala, Costa Rica, Bahamas, Cuba, Puerto Rico, Guadeloupe (Scheer and Thomaes 2018;
Specimens were found on leaf packs (February and March 2018).
This genus is distributed in North and South America, Africa, and Fiji (
Canada, United States, Mexico (Baja California; Estado de México; Chiapas, new state record) (
Collected on macrophytes and leaf packs (February and March 2018, dry season).
This genus is present from southwestern Canada south through western United States and Mexico, with a few species in Panama and one in Jamaica (
United States, Mexico (Baja California; Chiapas, new state record; Guanajuato; Oaxaca), Guatemala (
Collected on macrophytes and leaf packs, throughout the sampling period (February 2018 through February 2019, dry and rainy season).
This genus is distributed in the Nearctic, Neotropical, Palearctic, and Oriental regions, with 67 species (
Mexico (Chiapas, new state record; Oaxaca), Guatemala, El Salvador (
Collected on macrophytes and leaf packs, throughout the sampling period (February 2018 through February 2019, dry and rainy season); also collected with a bucket light trap.
This is a cosmopolitan genus with 90 species (
Canada, United States, Mexico (Baja California, Coahuila, Colima, Chiapas, Chihuahua, Ciudad de México, Durango, Estado de México, Guanajuato, Hidalgo, Jalisco, Michoacán, Morelos, Nayarit, Nuevo Léon, Oaxaca, Puebla, Querétaro, San Luis Potosí, Sinaloa, Sonora, Tamaulipas, Veracruz, Zacatecas), Guatemala, Honduras, Nicaragua, Costa Rica (
Collected on leaf packs (May 2018, rainy season).
This genus is distributed across the Americas and comprises 20 species and two subspecies (Nilsson and Hajék 2020), with eight species recorded from Mexico (
Mexico (Ciudad de México, Chiapas, Durango, Estado de México, Guanajuato, Hidalgo, Morelos, Oaxaca, Puebla, San Luis Potosí) (
Collected on leaf packs (May 2018, rainy season).
This genus is distributed worldwide and contains 65 species, nine of which are present in Mexico (
Mexico (Chiapas, Oaxaca), Guatemala (
Collected on leaf packs (May 2018, rainy season).
This genus occurs in the Australasian and Neotropical regions, with more than 100 described species (
Mexico (Chiapas, Morelos, Guerrero), Belize, Guatemala, Nicaragua, Costa Rica, Panama, Colombia, Venezuela, Peru, Brazil, Argentina (
Collected on substrates of gravel, macrophytes, and leaf packs, throughout the sampling period (February 2018 through February 2019, dry and rainy season).
Mexico (Chiapas, Guerrero), Guatemala, Costa Rica, Panama, Colombia, Venezuela, French Guiana, Ecuador, Peru (
Collected on substrates of gravel, macrophytes, and leaf packs, throughout the sampling period (February 2018 through February 2019, dry and rainy season).
This is the elmid genus with most species in the American continent, with 52 species and 2 subspecies currently known to this region (
Mexico (new country record, Chiapas), Peru (
Collected on substrates of gravel, macrophytes, and leaf packs, through most of the sampling months (except March, July, and September 2018, dry and rainy season).
This is a New World genus that comprises 22 species (
Mexico (Chiapas, Estado de México, Hidalgo, Jalisco, Morelos, Nayarit, Oaxaca, Tamaulipas, Veracruz), Belize, Nicaragua, Costa Rica (
Collected on substrates of gravel, macrophytes, and leaf packs, through all sampling months (February 2018 through February 2019, dry and rainy season).
Mexico (Chiapas, Durango, Estado de México, Hidalgo, Morelos, Oaxaca, Veracruz), Guatemala, Costa Rica, Nicaragua, Peru (
Collected on substrates of gravel, macrophytes, and litter, throughout all sampling months (February 2018 through February 2019, dry and rainy season).
Mexico (Chiapas, Colima, Estado de México, Morelos, Nuevo León, Oaxaca, San Luis Potosí, Veracruz), Guatemala, Costa Rica, Colombia, Peru, Brazil (
Collected on substrates of gravel, macrophytes, and leaf packs, throughout sampling months (February 2018 through February 2019, dry and rainy season).
Mexico (Chiapas, Morelos), Guatemala, Costa Rica, Peru, Trinidad and Tobago (
Collected on substrates of gravel, macrophytes, and leaf packs, throughout the sampling months (February 2018 through February 2019, dry and rainy season).
This genus is distributed in the southwestern United States and the Neotropical region, with 25 described species (
Mexico (new country record, Chiapas), Guatemala (
Collected on substrates of gravel, macrophytes, and leaf packs, throughout sampling months (February 2018 to February 2019, dry and rainy season).
This is a New World genus and comprises 21 species, with three recorded from Mexico (
Mexico (new country record, Chiapas), Nicaragua, Costa Rica, Panama.
The known altitudinal record of H. usitatus was 1,075 m (
Collected on substrates of gravel, macrophytes, and leaf packs, throughout sampling months (February 2018 through February 2019, dry and rainy season); also collected with a bucket light trap.
This is a North American genus and includes three species (
Mexico (Baja California; Chiapas, new state record; Coahuila; Estado de México; Guerrero; Jalisco; Nuevo León; Oaxaca; Tabasco; Veracruz) (
Collected on substrates of gravel, macrophytes, and leaf packs, throughout sampling months (February 2018 through February 2019, dry and rainy season).
This is a Nearctic and Neotropical genus, distributed from southern United States to South America, and comprises 49 species, 10 of which have been recorded from Mexico (
Mexico (Chiapas, Estado de México, Morelos, Oaxaca), Guatemala, Costa Rica, Nicaragua, Peru (
Collected on substrates of gravel, macrophytes, and leaf packs, throughout sampling months (February 2018 through February 2019, dry and rainy season).
Mexico (Chiapas, Guerrero, Morelos, Oaxaca, Veracruz), Guatemala, Honduras, Nicaragua, Costa Rica, Peru (
Collected on substrates of gravel, macrophytes, and leaf packs, throughout sampling months (February 2018 through February 2019, dry and rainy season).
This species was collected at level 5 (river 2, 1,776 m) on substrates of macrophytes and leaf packs, and was present throughout sampling months (February 2018 through February 2019, dry and rainy season). Specimens, including males, did not match known described species of the genus, although they are similar to M. leonilae. Male parameres of the specimens, in dorsal view, are slightly wider from the base to the apical portion, while in M. leonilae they are wider through the basal half.
Microcylloepus is widely distributed in the New World and comprises 30 species (
Mexico (Chiapas, Estado de Mexico, Morelos, Veracruz), Guatemala, Nicaragua, Costa Rica, Panama, Paraguay, Brazil (
Collected on substrates of gravel, macrophytes, and leaf packs, throughout sampling months (February 2018 through February 2019, dry and rainy season).
Mexico (Chiapas, Estado de Mexico). Previous altitudinal records of M. troilus are from 1,707 to 2,286 m (
Collected on substrates of gravel, macrophytes, and leaf packs, throughout sampling months (February 2018 through February 2019, dry and rainy season).
This species was collected at levels 1 (670 m), 2 (934 m), 3 (1,126–1,194 m), 4 (river 2, 1,619 m), and 5 (river 2, 1,776 m) on substrates of gravel, macrophytes, and leaf packs, throughout sampling months (February 2018 through February 2019, dry and rainy season). Specimens, including males, did not match exactly known described species of the genus, being close to M. angustus. Male genitalia of the specimens have the medium lobe slightly wider than M. angustus.
This genus is distributed across the American continent and has 50 described species (
Mexico (Chiapas, Estado de México, Morelos, San Luis Potosí, Tamaulipas), Guatemala, Costa Rica (
Collected on substrates of gravel, macrophytes, and leaf packs, in about half of the sampling period (February to May, and August 2018, and February 2019, dry and rainy season).
This genus is distributed in Central and South America, contains eight described species (
Mexico (new country record, Chiapas), Nicaragua, Panama, Colombia (
Collected on substrates of gravel, macrophytes, and leaf packs, during three months of the sampling period (February, April, and May 2018, dry and rainy season).
This genus is distributed from North America through northern South America, with six described species (
United States, Mexico (Chiapas, Colima, Guerrero, Hidalgo, Nuevo León, Puebla, Querétaro, San Luis Potosí, Tamaulipas, Veracruz), Belize, Guatemala, Honduras, Costa Rica, Panama, Venezuela, Brazil, Cuba, Jamaica, Haiti, Dominican Republic, Puerto Rico (
Collected on substrates of gravel, macrophytes, and leaf packs through four months of the sampling period (May, June, July, and August 2018, rainy season); also collected with a bucket light trap.
This is a New World, mostly Neotropical genus with 11 described species (
Mexico (Chiapas, Colima, Guerrero, Morelos), Belize, Panama, Venezuela (
Collected on substrates of gravel, macrophytes, and leaf packs, throughout the sampling months (February 2018 through February 2019, dry and rainy season).
This genus is distributed across the Nearctic and Neotropical region, with 56 species described (
United States, Mexico (Baja California Sur, Chiapas, Jalisco, Nayarit, Sinaloa, Sonora), Belize, Guatemala, Costa Rica, Panama, Venezuela (
This species was previously recorded at an altitudinal range of 5–914 m (
Collected with a bucket light trap (June 2018, rainy season).
This genus comprises 79 species worldwide (
Mexico (Chiapas, Durango, Tabasco, Veracruz), Costa Rica (
Collected near substrate of macrophytes (October 2018, rainy season).
The genus occurs on all continents except Antarctica and comprises more than 990 species described (
This species was collected at all sampled levels (670–1,776 m), on substrates of gravel, macrophytes, and leaf packs, throughout the sampling months (February 2018 through February 2019, dry and rainy season). Specimens were small and fragile, particularly males, and dissection was difficult, moreover genital morphology did not match species in keys, so genus-level identification was considered until further study; females were more abundant in collections.
This is a New World genus distributed from northern Canada to southern South America, comprising 60 described species (
Mexico (Chiapas, Colima, Distrito Federal, Jalisco, Estado de México, Michoacán, Morelos, Nayarit, Oaxaca, Puebla, Querétaro, San Luis Potosí, Sonora, Veracruz) (
Collected with a bucket light trap (July and August 2018, rainy season).
This genus comprises 29 species and is distributed across the Nearctic and Neotropical region (
This species was present at level 1 (670 m) and was collected on leaf packs (May 2018, rainy season). Specimens key out to an undescribed genus and species included in
This genus comprises 15 species, 13 of them distributed in the New World (
United States, Mexico (Chiapas, new state record; Oaxaca; San Luis Potosí; Tamaulipas), Guatemala, Costa Rica, Panama, Bahamas, Cuba, Jamaica, Dominican Republic, Puerto Rico, Virgin Islands, Guadeloupe (
Collected on substrate of macrophytes (February 2018, dry season).
The aquatic beetle fauna from Volcán Tacaná is distributed throughout the sampled altitudinal gradient (670–1,776 m), however our initial hypothesis is that species distribution would not be homogeneous. We applied a Parsimony Analysis of Endemism (PAE) as a fast approach to detect a potential faunal partition, with a general finding of the three lower altitudinal levels grouping together (i.e., sharing similar species) and about 40% of the species with a widespread altitudinal distribution. A first PAE (Fig.
Parsimony Analysis of Endemicity (PAE) of the altitudinal levels and sites of the aquatic beetle fauna of Volcán Tacaná, Chiapas, Mexico A most parsimonious tree of the five sampling levels, with levels 3–5 considered each as a unit (number of steps = 43, consistency index (CI) = 93, retention index (RI) = 83) B strict consensus of the five most parsimonious trees of the five sampling levels, with levels 3–5 considered as two separate units each (number of steps = 53, consistency index (CI) = 75, retention index (RI) = 63). Red numbers = species (see Table
The most diverse family was Elmidae (see some representatives on Fig.
Habitus of representative species of the three most diverse aquatic beetle families from Volcán Tacaná, Chiapas, Mexico A Elmoparnus pandus Spangler & Perkins, 1977 (Dryopidae) B Helichus suturalis LeConte, 1852 (Dryopidae) C Copelatus distinctus Aubé, 1838 (Dytiscidae) D Platambus americanus (Aubé, 1838) (Dytiscidae) E Cylloepus atys Hinton, 1946 (Elmidae) F Hexacylloepus metapa Silva-Polizei, Barclay & Bispo, 2020 (Elmidae) G Macrelmis leonilae Spangler & Santiago-Fragoso, 1986 (Elmidae) H Microcylloepus Troilus Hinton, 1940 (Elmidae) I Onychelmis longicollis (Sharp, 1882) (Elmidae).
Dytiscidae (see some representatives on Fig.
Dryopidae (see some representatives in Fig.
We attempt a general characterization of the fauna applying the criterion of Nearctic and Neotropical regions of
Among the 20 species of Elmidae, 14 occur only in the Neotropical region, while the remaining six, particularly those of Heterelmis, have a wide distribution (i.e., they occur in the Nearctic and Neotropical regions). Most dytiscid species, six out of 11, have a wide distribution through the Nearctic and Neotropics, while the other five occur only in the Neotropical region. Elmidae and Dysticidae have 80 and 50% of their distribution in the Brazilian subregions and the Mexican Transition Zone, respectively, with especial affinity to the Mesoamerican and Pacific domains. Dryopidae is represented by three species, two of them with records in the Neotropical region (Brazilian subregions and the Mexican Transition Zone) and one with Nearctic and Neotropical distribution. Gyrinidae (Gyretes boucardi), Hydraenidae (Hydraena sp.), and Lutrochidae (Lutrochus sp.), also have species with Neotropical affinity, whereas Epimotopidae (Epimetopus thermarum), Hydrophilidae (Tropisternus fuscitarsis), and Noteridae (Notomicrus sharpi) have species with a wide distribution in the New World. The latter six families also have an affinity to the Brazilian subregions, particularly to the Pacific and Mesoamerican domains.
Aquatic beetles were present at the five sampling levels (L1, 673 m; L2, 998 m; L3, 1,150–1,214 m; L4, 1,619–1,741 m; and L5, 1,763–1,776m). This agrees with the widespread distribution of aquatic beetles, as well as their high capacity to inhabit different aquatic environments from sea level to mountains of 4,000 m high or more (
Elmidae (riffle beetles) was the dominant group (20 spp.) and was present in all sampling levels. This coincides with previous findings in the Neotropics (e.g.,
Dytiscidae (predaceous diving beetles) was the second most diverse group (11 spp.) and was present mostly at levels 4 and 5, with only one species (Copelatus distinctus) at levels 3–5. Three species, Bidessonotus championi, Ilybiosoma flohrianum, and Uvarus subornatus were only observed at L4 (R2, 1,619 m), while Rhantus gutticollis and Thermonectus nigrofasciatus appeared only at L5 (R2, 1,776 m). This distribution may relate to the size of the streams at the higher levels, which were generally smaller and with weaker currents, so pools were more common, which appeared to be a suitable habitat for dytiscids; most collecting of dytiscids was at depositional zones of the stream. This agrees with a general preference of this family for lentic systems (
Dryopidae was the third family in species richness (3 spp.) and was present at lower elevations, with Dryops mexicanus and Helichus suturalis at levels 1–3, and Elmoparnus pandus only at level 1. This is a mostly tropical family, which appears to explain their presence at low elevations, although there are records at higher elevation in other areas (
The rest of the families were represented by one species each. Hydraenidae (Hydraena sp.) was observed at the five sampling levels, which agrees with the broad distribution of the group and that species of this genus occupy different types of habitats, from small streams to large rivers (
Species observed in levels 1–3 are usually of Neotropical affinity, while in levels 4 and 5 species with both Nearctic and Neotropical distribution increase. In general, most of the species are of Neotropical distribution with an affinity for the Pacific and Mesoamerican domains, which coincides with
The aquatic beetle fauna of Volcán Tacaná presents a high diversity, with Elmidae, Dystiscidae, and Dryopidae as the most species-rich families, being responsible for 85% of the species. Some families (e.g., Hydraenidae and Elmidae) are distributed along all the altitudinal range, while Dytiscidae is present particularly at the higher altitudinal levels (1,619–1776 m); Noteridae is also present at high altitude, but only in a river located at 1,741 m. Remaining families, Dryopidae, Epimetopidae, Gyrinidae, Hydrophilidae, and Lutrochidae are present in lowlands (670–1,214 m). The aquatic beetle fauna of Volcán Tacaná presents a general partition in two well-defined groups: a lower altitude fauna (between 670, 934 and 1,150–1,214 m, levels 1–3) and a higher altitude fauna (between 1,619 and 1,776 m, levels 4 and 5). This fauna has an affinity to the Pacific and Mesoamerican biogeographic domains.
Our thanks go to the authorities of the localities Finca Alianza, Finca Monte Perla, Ejido El Águila, Ejido Benito Juárez El Plan, and Cantón San Isidro, as well as to Francisco J. Jiménez González, director of the Tacaná Volcano Biosphere Reserve, for authorizing our research. We also thank Rodolfo Cancino and Johar Almaraz for help and encouragement during field work. Thanks to Hellen Martínez-Roldán for her support in making the map of sampling points, thanks also to Alana Brunini for help with reference and text editing. We thank associate editor Ernesto Rázuri-Gonzales and one anonymous reviewer for helpful and constructive reviews. CCM acknowledges Programa de Becas Posdoctorales DGAPA-UNAM 2019–2021 for a postdoctoral fellowship. ACR thanks project “Biodiversidad de Neuroptera en México: un enfoque taxonómico integrativo” (CONACYT CB2017-2018, A1-S-32693) for general support. Alba Magali Luna-Luna thanks Consejo Nacional de Ciencia y Tecnología (CONACYT, Mexico) for a scholarship through Doctorado en Ciencias Biológicas y de la Salud, Universidad Autónoma Metropolitana, Mexico City; this contribution is part of the requirements of AMLL to obtain her doctoral degree at Universidad Autónoma Metropolitana. This work was supported by project PAPIIT-UNAM IN207517 (Aportaciones a la taxonomía y filogenia del orden Neuroptera (Insecta) en México, 2017–2019) granted to ACR.
Collecting data of examined material of the new records of species for Mexico; all specimens are deposited at Colección Nacional de Insectos (CNIN), UNAM. LV1-LV5 = sampled levels; R1 and R2 = sampled rivers; m = male, f = female; * = specimens collected with bucket light trap (as explained in materials and methods).
Sample data (day/month/year) | ELMIDAE | DYTISCIDAE | |||
---|---|---|---|---|---|
Cylloepus atys Hinton, 1946 | Hexacylloepus metapa Silva-Polizei, Barclay & Bispo, 2020 | Hexanchorus usitatus Spangler & Santiago-Fragoso, 1992 | Onychlemis longicollis (Sharp, 1882) | Bidessonotus championi J. Balfour-Browne, 1947 | |
10/02/2018 | LV1R1 (2m) | LV1R1 (7m, 4f) | |||
11/02/2018 | LV2R1 (1m) | LV2R1 (2f) | |||
13/02/2018 | LV1R1 (1f) | ||||
17/02/2018 | LV4R2 (1m) | ||||
10/03/2018 | LV1R1 (2m, 3f) | LV1R1 (10m, 8f); LV2R1 (1m, 2f)* | |||
09/04/2018 | LV1R1 (10m, 14f) | ||||
10/04/2018 | LV2R1 (1m, 3f) | ||||
11/04/2018 | LV3R1 (1m); LV3R2 (2f) | ||||
13/04/2018 | LV3R2 (2m, 2f) | ||||
20/04/2018 | LV5R1 (1m, 1f) | ||||
07/05/2018 | LV1R1 (3m) |
LV1R1 (44m, 58f); (59m, 76f)* | |||
09/05/2018 | LV2R1 (1m, 1f) | LV2R1 (2m, 2f) | LV2R (1f) | ||
11/05/2018 | LV3R1 (1f) | LV3R1 (1m, 2f) | |||
12/05/2018 | LV3R2 (2m, 1f) | LV3R2 (28m, 26f); (2f)* | |||
08/06/2018 | LV1R1 (1f) | LV1R1 (2m, 6f) | |||
09/06/2018 | LV2R1 (4m, 9f) | ||||
15/06/2018 | LV4R2 (1m, 3f) | ||||
22/06/2018 | LV5 R1 (1m) | ||||
08/07/2018 | LV1R1 (3m, 5f) | LV1R1 (34m, 38f); (16m, 63f)* | |||
09/07/2018 | LV1R1 (3m, 7f) | LV2R1 (45m, 31f) | LV2R1 (10m, 18f); (15m, 11f)* | ||
10/07/2018 | LV3R2 (12m, 25f) | LV3R2 (17m, 24f) | |||
11/07/2018 | LV3R1 (6m, 3f) | LV3R1 (32m, 25f) | |||
13/07/2018 | LV4R2 (1m) | ||||
14/07/2018 | LV4R1 (1m); LV4R2 (1m) | LV4R2 (1f) | |||
20/07/2018 | LV5R1 (1f) | LV5R1 (2m, 3f) | |||
07/08/2018 | LV1R1 (2m, 1f) | LV1R1 (10m, 19f) | LV1R1 (1m); (1m, 2f)* | ||
08/08/2018 | LV2R1 (1f) | LV2R1 (27m, 20f) | |||
10/08/2018 | LV3R1 (1m) | LV3R1 (8m, 13f); LV3R2 (20m, 43f) | LV3R1 (1m) | ||
12/08/2018 | LV4R2 (3m, 4f); LV4R2 (3m, 4f) | ||||
13/08/2018 | LV4R2 (1f) | ||||
17/08/2018 | LV5R2 (6m, 2f) | ||||
04/09/2018 | LV1R1 (10m, 3f) | LV1R1 (34m, 17f) | |||
05/09/2018 | LV2R1 (1m) | ||||
07/09/2018 | LV3R1 (4m, 2f) | ||||
03/10/18 | LV1R1 (2m, 2f) | LV1R1 (11m, 26f) | |||
04/10/18 | LV2R1 (6m, 13f) | ||||
12/10/2018 | LVR2 (2f); LV5R2 (1m, 1f) | ||||
02/11/2018 | LV1R1 (5m, 6f); LV2R1 (10m, 5f) | ||||
07/11/2018 | LV3R2 (1m, 2f) | LV3R2 (4m, 8f) | |||
23/11/2018 | LV5R2 (2m) | LV5R1 (1f) | |||
03/12/2018 | LV2R1 (2m, 3f) | LV2R1 (3m, 7f) | |||
04/12/2018 | LV4R2 (2f) | ||||
06/12/2018 | LV3R2 (3m, 13f) | ||||
09/12/2018 | LV5R1 (2m) | ||||
04/01/2019 | LV2R1 (2f) | LV2R1 (7m, 15f) | |||
06/01/2019 | LV3R2 (1m, 2f) | LV3R1 (2m, 2f) | |||
04/02/2019 | LV1R1 (4f) | LV2R1 (1m, 3f) | LV1R1 (1m, 7f); LV2R1 (6m, 10f) | ||
05/02/2019 | LV3R1 (12m, 19f) |