Research Article |
Corresponding author: Pedro de Souza Castanheira ( pedrocastanheira.bio@gmail.com ) Academic editor: Danilo Harms
© 2022 Pedro de Souza Castanheira, Renner Luiz Cerqueira Baptista, Francisca Sâmia Martins Oliveira.
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:
Castanheira PS, Baptista RLC, Oliveira FSM (2022) Five new species of the long-jawed orb-weaving spider genus Tetragnatha (Araneae, Tetragnathidae) in South America, with a key to the species from Argentina and Brazil. Evolutionary Systematics 6(2): 175-210. https://doi.org/10.3897/evolsyst.6.91418
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Five new species in the long-jawed orb-weaving spider genus Tetragnatha Latreille, 1804 are described from South America: Tetragnatha amazonica sp. nov. (Venezuela); T. cristata sp. nov. (Argentina and Brazil); T. didorata sp. nov. (Brazil); T. oncognatha sp. nov. (Brazil); and T. pradoi sp. nov. (Argentina and Brazil). A key to the 21 species of Tetragnatha from Argentina and Brazil is provided, completing the revision of the genus for these countries. The female of T. cladognatha Bertkau, 1880 is redescribed and a neotype is proposed, and its male is described for the first time. Additionally, we update the taxonomic status of the following six South American species: Tetragnatha labialis Nicolet, 1849 and T. americana Simon, 1896 are considered new junior synonymies of T. nitens (Audouin, 1826); and Tetragnatha bishopi Caporiacco, 1947, T. linearis Nicolet, 1849, T. similis Nicolet, 1849 and T. sternalis Nicolet, 1849 are proposed as nomina dubia due to missing or juvenile type-material.
Taxonomy, systematics, Neotropical Region, Tetragnathinae
One distinctive family of Araneomorphae is Tetragnathidae Menge, 1886, whose members usually build typical horizontal prey-capture orb-webs. Currently, 46 described genera and 982 species are distributed worldwide, with 16 genera recorded for the Neotropical region (
Tetragnathidae was originally divided into two subfamilies, “Metinae” (currently Metainae) and Tetragnathinae (
Tetragnatha has a cosmopolitan distribution, comprising 322 described species including nine subspecies (
Currently, there are verified records for 11 Tetragnatha species from Argentina and 16 from Brazil (
This study includes an updated description of Tetragnatha, a redescription of Tetragnatha cladognatha Bertkau, 1880, descriptions of five new species, a key to all species of the genus from Argentina and Brazil, and also additional taxonomic changes concerning some Neotropical species.
Morphological terminology follows
Specimens were cleaned using a Cristofoli Ultrasonic Cleaner. They were then positioned in a 70% alcohol gel or glass spheres for automontage photographs and measurements, taken with a Leica DFC450 camera mounted on a Leica M205C stereoscope microscope at the Laboratório de Entomologia, Universidade do Brasil/ Universidade Federal do Rio de Janeiro. All photos and plates were edited and mounted using the software package Photoshop CS5.1. Measurements are given in millimetres. Carapace length was measured from the anterior margin of the clypeus (i.e. excluding the chelicerae) to the posterior border. Total length was measured from the anterior margin of the clypeus to the posterior edge of the abdomen, including the spinnerets. Chelicerae curvature was measured with the use of a protractor. The description of the position of teeth and fang cusps (upward, downward, distalward and basalward) took into account the direction of the chelicerae (
For scanning electron microscope (SEM), preparations were submitted to critical point drying techniques and mounted on adhesive copper tape (Electron Microscopy Sciences, EMS 77802), affixed to a stub. Examination was carried out under high vacuum with a JEOL JSM-6510 microscope at Laboratório de Imagens (Labim), Instituto de Biologia, Universidade Federal do Rio de Janeiro (
For map construction, we used the software QGis 3.16.8. Geographic coordinates were extracted directly from original labels. When no coordinate information was available on the label, estimates of the closest nearby locality were extracted from resources such as the Global Gazetteer (version 2.3, available from http://www.fallingrain.com/world/index.html) or Google Earth (version 9.1.39.1, available from https://earth.google.com/web/).
Structures of chelicera
a male dorsal apophysis, used to lock the fangs of females during copulation.
AXl auxiliary guide tooth of the lower row, present in some species.
AXu auxiliary guide tooth of the upper row, above Gu, present in some species.
BC basal cusp on the cheliceral fang of females.
CB cheliceral bulge, a protruding area between the two rows of teeth, near the base of the fang.
CRu cheliceral crest, a protruding marked area on the upper teeth row.
CRl cheliceral crest, a protruding marked area on the lower teeth row.
Gu guide tooth of the upper (or dorsal) row.
Gl guide tooth of the lower (or ventral) row.
IC inner cusp of fang.
L2–n teeth on the lower row numbered from the distal end after Gl.
MC median cusp of the fang.
OC outer cusp of fang.
rsu remaining proximal teeth on the upper row of males and females after the last specialized tooth, like for example the ‘T’ in males of some species.
rsl remaining proximal teeth on the lower row of males and females after the last specialized tooth.
sl first major tooth after Gu in the upper row of males (absent in some species).
T elongated tooth in the upper row of some males.
t a tooth or prominence found in males of some species.
U2–n teeth on the upper row numbered from the distal end after Gu.
Other structures
Eyes: AME = anterior median eyes and ALE = anterior lateral eyes. Male pedipalps: E = embolus; C = conductor; P = paracymbium (including K = ectal knob, L = mesal translucent lobe, N = apical notch); Y = cymbium. Female genitalia: GF = genital fold; Sp = spermatheca; CS = central membranous sac.
Our revision of Tetragnatha was based on 120 males, 239 females and 59 juveniles in 13 species for Argentina, and 831 males, 1,038 females and 308 juveniles in 20 species for Brazil, four of which are new to science and herein described (Table
Summary of Tetragnatha in Argentina and Brazil, local species distribution, remarks and material examined, including records from this paper. (Argentinian provinces: BA = Buenos Aires; CB = Córdoba; CC = Chaco; CB = Córdoba; CN = Corrientes; CT = Catamarca; ER = Entre Ríos; JY = Jujuy; LP = La Pampa; LR = La Rioja; MN = Misiones; MZ = Mendoza; NQ = Neuquén; RN = Río Negro; SA = Salta; SC = Santa Cruz; SE = Santiago del Estero; SF = Santa Fe; TM = Tucumán; Brazilian states: AL = Alagoas; AM = Amazonas; AP = Amapá; BA = Bahia; ES = Espírito Santo; GO = Goiás; MA = Maranhão; MG = Minas Gerais; MS = Mato Grosso do Sul; MT = Mato Grosso; PA = Pará; PB = Paraíba; PE = Pernambuco; PI = Piauí; PR = Paraná; RJ = Rio de Janeiro; RS = Rio Grande do Sul; SC = Santa Catarina; SE = Sergipe; SP = São Paulo; TO = Tocantins).
Species | Distribution in Argentina (provinces) | Distribution in Brazil (states) | Distribution outside Brazil and Argentina according to this study and the |
Remarks | Material examined from Argentina | Material examined from Brazil |
---|---|---|---|---|---|---|
(M: males, F: females, J: juveniles) | (M: males, F: females, J: juveniles) | |||||
T. argentinensis Mello-Leitão, 1931 | BA, CT, CB, ER, MN | MG, MT, PR, RJ, RS, SC, SP | Uruguay |
|
31M, 57F, 11J | 75M, 100F, 22J |
T. bogotensis Keyserling, 1865 | CB, JY, LR, MN, SA, SE, TM | AL, BA, ES, MG, MT, PA, PB, PE, PI, PR, RJ, RS, SC, SP, TO | Mexico to Paraguay, Caribbean, Italy, Africa, Seychelles, Yemen, India, Nepal, Bangladesh, China |
|
5M, 12F, 1J | 114M, 187F, 29J |
T. caudata Emerton, 1884 | BA | – | North and Central America, Cuba, Jamaica and Uruguay |
|
1M, 3F | – |
T. chauliodus (Thorell, 1890) | – | RJ | China, Japan, Myanmar to Papua New Guinea |
|
– | 1M, 1F, 2J |
T. cladognatha Bertkau, 1880 | MN | ES, MG, MS, PR, RJ, RS, SC, SP | – | neotype provided | 6M, 17F, 11J | 55M, 95F, 26J |
T. cristata sp. nov. | MN | RS, SC, SP | – | female unknown | 1M, 4J | 29M, 9J |
T. didorata sp. nov. | – | PA, PR, RS, SC | – | female unknown | – | 4M |
T. elongata Walckenaer, 1841 | MN | PA, PR, RS, SC | Nearctic and Neotropical Regions |
|
3M, 6F, 2J | 46M, 54F, 5J |
T. guatemalensis O. Pickard-Cambridge, 1889 | – | MS, RO, RS, SC, SP, TO | North and Central America, Cuba, Jamaica, Paraguay |
|
– | 16M, 43F |
T. jaculator Tullgren, 1910 | MN | MA, MG, MS, PA, PB, PE, PR, RJ, RS, SC, SE, SP | Africa to China, New Guinea. Introduced to the Caribbean and South America |
|
1M | 87M, 35F, 28J |
T. keyserlingi Simon, 1890 | – | AL, AM, MS, PA, PR, RJ, RS, SP, TO | Central America, Caribbean, Africa, Korea, China, India to Philippines, New Hebrides (Vanuatu), Polynesia |
|
– | 18M, 25F, 7J |
T. laboriosa Hentz, 1850 | NQ, RN, SC | RS, SE, SP | Alaska to Chile, Falkland Is. |
|
24M, 33F, 9J | 6M, 3F, 5J |
T. mandibulata Walckenaer, 1841 | – | AM, AP, ES, MS. MT, PA, RJ, SP | Central America, Caribbean, Colombia, Guyana, West Africa, India to Philippines, Australia |
|
– | 11M, 37F, 2J |
T. megalocera Castanheira & Baptista, 2020 | – | ES, RJ, RS, SC, SP | – |
|
– | 35M, 27F, 29J |
T. nitens (Audouin, 1826) | BA, CC, CB, CN, CT, ER, LP, LR, MZ, MN, RN, SC, SF | ES, GO, MG, MT, MS, PA, PB, PE, PI, PR, RJ, RS, SC, SP, TO | Tropical and subtropical Asia. Introduced: Americas, Macaronesia, Mediterranean, Madagascar, Pacific Is., New Zealand |
|
46M, 107F, 20J | 276M, 370F, 118J |
T. oncognatha sp. nov. | – | RJ, RS, SC, SP | – | – | – | 13M, 5F, 1J |
T. paraguayensis (Mello-Leitão, 1939) | MN | MS, SP | Paraguay | male unknown – |
1F | 2F |
T. pradoi sp. nov. | BA | RS | – | male unknown | 2F | 1F |
T. renatoi Castanheira & Baptista, 2020 | MN | PE, PR, RO, RS, SC, SP | Venezuela |
|
1M, 1F | 18M, 1F |
T. tenuissima O. Pickard-Cambridge, 1889 | MN | AM, AP, BA, ES, MT, MS, PA, PE, PI, PR, RJ, SE, SP | Mexico, Central America, Caribbean |
|
1M | 20M, 36F, 25J |
T. vermiformis Emerton, 1884 | – | MS, MT, PB, PE, PR, RJ, RS, SP | Temperate and tropical Asia. Introduced to North, Central America, South America |
|
– | 7M, 16F, 3J |
Tetragnatha nitens was the most abundant species examined during this study, with 173 specimens (46 males, 107 females and 20 juveniles) from Argentina and 764 specimens (276 males, 370 females and 118 juveniles) from Brazil. It was also the most widespread, occurring in 12 provinces in Argentina and, alongside T. bogotensis, in 15 Brazilian states. Therefore, our data support the status of T. nitens as the world`s most widespread and common Tetragnatha species.
In Argentina, the second most widespread species was T. bogotensis (seven provinces), followed by T. argentinensis (five provinces). There were no species exclusively known from Argentina. Among the species we studied, T. caudata has not yet been found in Brazil, but besides Argentina, it also occurs in Uruguay, North and Central America and the Caribbean. Tetragnatha tenuissima (known from 13 states) and T. jaculator (12 states) are the third and fourth most widespread species in Brazil. Tetragnatha didorata sp. nov., T. megalocera and T. oncognatha sp. nov. are currently the only species endemic to Brazil.
There were nine species limited to only one Argentinian province: T. caudata and T. pradoi sp. nov. (both found in Buenos Aires), and T. cladognatha, T. cristata sp. nov., T. elongata, T. jaculator, T. paraguayensis, T. renatoi and T. tenuissima (all found in Misiones). In contrast, only two species were found in a single Brazilian state: T. chauliodus (likely introduced from Asia), with a single record for Rio de Janeiro state, and T. pradoi sp. nov., for Rio Grande do Sul state.
Class Arachnida Cuvier, 1812
Order Araneae Clerck, 1757
Tetragnatha Latreille, 1804, Tableau Méthodique des Insectes, in Nouveau Dictionnaire d’Histoire Naturelle, 24: 135.
Eugnatha Audouin in Savigny, 1825, Explications sommaires des Planches d’Arachnides de I’Egypte et de la Syrie, p. 119.
Eucta Simon, 1881, Arachnides de France, 5: 5 (Type species by monotypy E. gallica Simon, 1881).
Arundognatha
Wiehle, 1963, Tetragnathidae in Tierwelt Deutschlands, 49: 47. (Type species T. striata L. Koch, 1862 designated by
Tetragnatha extensa (Linnaeus, 1758)
Tetragnatha differs from Dolichognatha, Pachygnatha and Glenognatha by its elongate and tubular-shaped abdomen, normally covered by guanine crystals. It further differs from Dolichognatha in lacking an epigynum (having a genital fold instead) (Figs
Carapace longer than wide, normally with an elevated anterior part, without projections or bands (e.g., Figs
Cosmopolitan.
Males
1 | Tegulum slanted ( |
2 |
– | Tegulum not slanted (e.g., Fig. |
3 |
2 | Eyes with ALE and PLE not touching each other; chelicerae with no carved ‘a’, reduced Gu and straight ‘sl’; pedipalps with very short tibia, tegulum extremely slanted, filiform conductor and paracymbium triangular ( |
T. jaculator |
– | Eyes with ALE and PLE touching; chelicerae with ‘a’ long and carved on its inner margin, Gu long, pointed and distalward projected, and ‘sl’ short, triangular and basalward projected; pedipalps with tibia extremely elongated, tegulum slightly slanted, conductor ribbon-like with triple pleats and paracymbium much longer than wide ( |
T. elongata |
3 | Abdomen elongated, slender, without a pointed projection overhanging spinnerets (e.g., Figs |
5 |
– | Abdomen with such projection (e.g., Fig. |
4 |
4 | Eyes with ALE and PLE touching each other; chelicerae much elongated with thin and very elongated ‘a’ and ‘t’; ‘T’ absent and reduced Gl; palps with elongated tibia (Fig. |
T. didorata sp. nov. |
– | Eyes with ALE and PLE not touching; chelicerae short with thick and short ‘a’; ‘t’ absent; ‘sl’ reduced and basalward projected; ‘T’ thick and elongated; Gl long; palps with very short tibia ( |
T. caudata |
5 | Abdomen, very thin and slender, normally with dark lateral patches (e.g., |
6 |
– | Abdomen larger and bulkier, not slender, without black patches (e.g., |
9 |
6 | Pedipalps with embolus completely covered by the conductor, paracymbium elongated with translucent lobe occupying at least 50% of its width ( |
7 |
– | Pedipalps with embolus filiform and not completely wrapped by the conductor, paracymbium very short and triangular, with rounded notch and narrow translucent lobe ( |
T. tenuissima |
7 | Chelicerae with ‘a’ short, Gu and Gl reduced and rounded, ‘t’ and ‘T’ absent and fangs with short inner cusp; pedipalps with paracymbium almost as longer as wide, subquadrate, with straight notch ( |
T. renatoi |
– | Chelicerae with ‘a’ elongated and curved, ‘T’ and Gl pointed and long, fangs without cusps; pedipalps with paracymbium longer than wide not subquarate with pointed notch ( |
8 |
8 | Chelicerae with a clear swollen behind ‘a’, ‘t’ and Gu absent, ‘sl’ reduced and pointed, ‘T’ with large basis, L2 curved with large basis, fangs closing between teeth rows; pedipalps with conductor tip very enlarged and paracymbium with pointed notch ( |
T. megalocera |
– | Chelicerae with ‘t’ small and rounded, Gu elongated, pointed and slightly basalward projected, ‘sl’ absent, ‘T’ very thin and pointed, Gl elongated, L2 small and fangs closing above ‘T’; pedipalps with embolus with curved tip, opening below the transparent conductor tip, covering the embolus as a cap, paracymbium with notch rounded and undivided ( |
T. chauliodus |
9 | Chelicerae with elongated ‘T’ (e.g., Figs |
10 |
– | Chelicerae without ‘T’ (e.g., |
17 |
10 | Pedipalps with paracymbium bearing elongated finger-like projection and slanted notch ( |
T. guatemalensis |
– | Pedipalps with paracymbium either excavated or not, without finger-like projection (e.g., Figs |
11 |
11 | Abdomen thin, elongated; chelicerae very long, Gu long, thin and slanted, ‘sl’ absent, ‘T’ very elongated with a narrow basis, distalward projected; pedipalps with tip of conductor and embolus hook-like (Figs |
12 |
– | Abdomen short to median-sized; chelicerae short, Gu reduced, ‘sl’ present or absent, ‘T’ not elongated with larger basis; pedipalps with conductor wrapping the embolus tip or curved bird-head shaped (e.g., Figs |
14 |
12 | Chelicerae with ‘t’ present, Gu with almost the same length as ‘T’, Gl and L2 thinner with narrow bases; pedipalps with paracymbium with rounded uncarved notch and very reduced translucent lobe ( |
T. keyserlingi |
– | Chelicerae with ‘t’ absent, Gu median much shorter than ‘T’, Gl and L2 with larger basis; pedipalps with paracymbium bearing carved notch and conspicuous translucent lobe (Figs |
13 |
13 | Chelicerae with Gl and L2 almost straight and having large bases; pedipalps with thinner tibia, conductor tip curved and very pointed, paracymbium with translucent lobe ending on the same level of paracymbium proper, forming a carved notch; epiandrous field with narrow median division, with 26 spigots (Figs |
T. cladognatha |
– | Chelicerae with Gl and L2 not straight, Gl with wide basis, L2 rounded with narrow basis; pedipalps with thicker tibia, conductor tip curved, large and moderately pointed, paracymbium with translucent lobe reaching over the paracymbium proper, forming a pronounced carved notch; epiandrous field with wide median division, with 18 spigots ( |
T. argentinensis |
14 | Chelicerae with Gu located on fang groove and ‘sl’ present; pedipalps with conductor very elongated, ending in a thin basalward projected bird-head/ribbon shaped tip, paracymbium wide, not slanted, with rounded notch ( |
T. laboriosa |
– | Chelicerae with Gu not located on fang groove, ‘sl’ absent; pedipalps with conductor ending in rounded tip, paracymbium slightly slanted (e.g., Figs |
15 |
15 | Eyes with ALE and PLE not touching; chelicerae without cheliceral bulge and lower crest, ‘a’ curved, Gu and ‘T’ slightly apart from the upper teeth row, AXl present; pedipalps with paracymbium very narrow, with notch rounded and translucent lobe reduced ( |
T. vermiformis |
– | Eyes with ALE and PLE touching; chelicerae with a conspicuous bulge on upper row and a lower crest, ‘a’ straight and slanted, Gu reduced, projected distalward, ‘T’ slightly located on teeth groove, AXl absent; pedipalps with wide paracymbium, with notch slightly curved and translucent lobe broad (Figs |
16 |
16 | Chelicerae with rounded and larger cheliceral bulge (CB), ‘a’ with reduced carving on its tip, AXu very reduced, lower crest going beyond L2, midway from reaching L3; pedipalps with embolus opening on ventral side of conductor and paracymbium with notch with large and slightly curved rounded tip (Figs |
T. oncognatha sp. nov. |
– | Chelicerae with smoother CB, ‘a’ with conspicuous dent on its lower size, AXu absent, lower crest very large, rounded and not reaching L2; pedipalps with embolus opening on dorsal side of conductor, paracymbium with notch curved and not very large (Figs |
T. cristata sp. nov. |
17 | Chelicerae with ‘a’ pointed, not carved, ‘t’ and AXu absent, Gu with very large basis, placed on fang groove; pedipalps with conductor very flattened, winglet-shaped ( |
T. mandibulata |
– | Chelicerae with ‘a’ carved, ‘t’ and AXu very elongated and pointed, Gu small, apart from fang groove; pedipalps with conductor very large and rounded ( |
18 |
18 | Chelicerae with AXu with large basis, slanted, ‘t’ thick, slanted, Gu distalward projected, longer than U2; pedipalps with median sized tibia, conductor with its tip large, rounded, completely enfolding embolus tip, paracymbium longer, overreaching distal margin of tegulum, translucent lobe occupying around 40% of its maximum width, and notch formed by tip of paracymbium proper clearly longer than tip of lobe ( |
T. bogotensis |
– | Chelicerae with AXu with thin basis, very slanted, ‘t’ sickle-like, elongated, Gu basalward projected, smaller than U2; Pedipalps with long tibia, conductor with its tip curved and flattened, hiding embolus tip, paracymbium shorter, not reaching the distal margin of tegulum, and very wide, with translucent lobe occupying more than 70% of its maximum width, and notch formed by tip of paracymbium proper placed about the same level of the tip of lobe ( |
T. nitens |
Females
1 | Abdomen elongated, slender, with a long tail-shaped pointed projection overhanging spinnerets ( |
2 |
– | Abdomen without such projection | 3 |
2 | Short projection overhanging spinnerets with around ¼ of the abdomen length; chelicerae with L2 a bit larger than L3 ( |
T. caudata |
– | Elongated projection overhanging spinnerets with around ½ of the abdomen length; chelicerae with L3 with very wide basis and massive size, much larger than L2, and slanted ( |
T. paraguayensis |
3 | Genital fold around as long as wide (e.g., Fig. |
4 |
– | Genital fold longer than wide (e.g., Fig. |
12 |
4 | Internal genitalia without a central membranous sac (CS) ( |
5 |
– | Internal genitalia with central membranous sac (CS) (see e.g., |
6 |
5 | Chelicerae with Gu slightly displaced from fang groove, Gl a little basalward projected; spermathecae kidney-like, located on edge of plate ( |
T. vermiformis |
– | Chelicerae with Gu located on edge of fang groove, Gl distalward projected; spermathecae with both lobes long, arched, with rounded tips of about the same size ( |
T. laboriosa |
6 | Central membranous sac (CS) slender ( |
7 |
– |
CS rounded (e.g., |
8 |
7 | Abdomen slender and very thin, more than 7× longer than wide; chelicerae very elongated, with clear upper crest, pointed outer cusp and Gl slightly curved downwards; genital fold with straight posterior rim; spermathecae cylindrical, much longer than wide ( |
T. tenuissima |
– | Abdomen less than 4× longer than wide; chelicerae short and laterally bulged, with no crests or cusps; genital fold with curved posterior rim; spermathecae mushroom-shaped, wider than long ( |
T. jaculator |
8 | Central membranous sac poorly sclerotized and probably not functional ( |
9 |
– | Central membranous sac very sclerotized (e.g., |
10 |
9 | Abdomen thin and very slender, more than 9× longer than wide; chelicerae with Gu reduced, slightly displaced from fang groove, L2 bulky, extremely elongated, distalward projected, fangs without outer cusp; genital fold with straight posterior rim, almost on the same level of book-lungs plate; four rounded spermathecae, two on each side of the plate ( |
T. megalocera |
– | Abdomen very enlarged anteriorly, around 2.5× longer than wide; chelicerae with Gu thick, rounded, Gl large, triangular, L2 small, rounded, fangs bearing a clear outer cusp; genital fold with small cylindrical posterior rim, not on the same level of book-lungs plate; two massive, curved spermathecae, formed of two large tubes ending in rounded tips ( |
T. elongata |
10 | Four oval spermathecae, small central membranous sac ( |
T. guatemalensis |
– | Two massive spermathecae, large central membranous sac (e.g., Fig. |
11 |
11 | Abdomen with dark lateral line; chelicerae with L2 equidistant between Gl and L3; genital fold with straight posterior rim; two massive rounded spermathecae, central membranous sac oval (Figs |
T. oncognatha sp. nov. |
– | Abdomen with no lateral lines; chelicerae with L2 and L3 very close, almost adjoined; genital fold with rounded posterior rim; two large subquadrate spermathecae, central membranous sac perfectly rounded ( |
T. renatoi |
12 | Chelicerae bearing fangs with large median cusps (MC) (Figs |
13 |
– | Chelicerae without MC (e.g., |
15 |
13 | Abdomen slender and bearing lateral dark patches; chelicerae with large median cusp facing lower teeth row, presence of basal cusp near fang basis; central membranous sac cylindrical, reaching over anterior tip of spermathecae ( |
T. chauliodus |
– | Abdomen large and without dark patches; chelicerae with median cusp facing upper teeth row, without basal cusp; central membranous sac with enlarged head, reaching around middle level of spermathecae (Figs |
14 |
14 | Abdomen anteriorly enlarged; chelicerae without crests, Gu almost straight, L2 with large rounded basis, fang with semi-circular basal half bearing pointed inner cusp; genital fold with a strong concavity on posterior rim (Figs |
T. cladognatha |
– | Abdomen cylindrical, without apparent enlargement; chelicerae bearing clear upper crest, Gu distalward projected, L2 with a normal, not enlarged basis, fang without semi-circular basal half and without inner cusps; genital fold with a smooth concavity on posterior rim ( |
T. argentinensis |
15 | Chelicerae with deep upper and lower crests; central membranous sac wide, thin and rounded, on top of extremely elongated stalk ( |
T. keyserlingi |
– | Chelicerae without crests; central membranous sac cylindrical or oval, with small to median-sized stalk (e.g., |
16 |
16 | Abdomen with pointed posterior projection; chelicerae with outer and inner cusps; genital fold extremely elongated and slender; central membranous sac cylindrical (Fig. |
T. pradoi sp. nov. |
– | Abdomen without projection; chelicerae without cusps; genital fold not as elongated; central membranous sac rounded (e.g., |
17 |
17 | Chelicerae without conspicuous cheliceral bulges (CB) and reduced AXl ( |
T. nitens |
– | Chelicerae with CB and bearing elongated and pointed AXl ( |
18 |
18 | Chelicerae with curved conspicuous cheliceral bulge, Gl thin, straight and pointed, basal cusp (BC) not slanted; central membranous sac small on same level as basis of spermathecae ( |
T. bogotensis |
– | Chelicerae with smooth cheliceral bulge, Gl finger-like, slanted and distalward projected, basal cusp slanted; central membranous sac massive, rounded, larger than the spermathecae and reaching over their anterior end ( |
T. mandibulata |
Tetragnatha cladognatha Bertkau, 1880: 79, pl. 2, fig. 27 (♀)
Tetragnatha cladognatha: Brazil: female, holotype, Rio de Janeiro, not located (presumed lost). Brazil, Rio de Janeiro • Neotype female herein designated, Rio de Janeiro, Parque Estadual da Pedra Branca, Camorim (Sede), 22°58'12.0"S, 043°26'16.4"W, 160 m, 09.i.2014, RLC Baptista leg. (
Argentina, Misiones • 1 female, Parque Provincial Uruzú, 1° Uruzú, 25°50′S, 54°08'W, 02.ii.1988, P. Goloboff and Szumik leg. (
Males and females most resemble T. argentinensis (
Tetragnatha cladognatha female. A. Live specimen, dorsal view (carapace and chelicerae); B–H. Neotype female (
Tetragnatha cladognatha male. A. Live specimen, dorsal habitus (not collected); B. Dorsal habitus (
Tetragnatha cladognatha SEM photos. A, B. Male left chelicera (
Female (based on neotype
Measurements. Total length 12.5. Carapace 4.4 long, 2.3 wide. Abdomen 10.0 long, 2.9 wide. Left chelicera 2.9 long, 0.5 wide. Leg formula I–IV–II–III. Leg I: femur 13.3, patella 1.8, tibia 11.5, metatarsus 11.5 and tarsus 2.3. Leg II: patella + tibia 8.6. Leg III: patella + tibia 3.4. Leg IV: patella + tibia 7.3.
Male (based on
Measurements. Total length 6.40. Carapace 2.0 long, 1.2 wide. Abdomen 4.5 long, 1.0 wide. Left chelicera 2.6 long, 0.5 wide. Leg formula I–IV–II–III. Leg I: femur 7.4, patella 0.8, tibia 7.8, metatarsus 8.9 and tarsus 1.2. Leg II: patella + tibia 5.1. Leg III: patella + tibia 1.9. Leg IV: patella + tibia 4.5.
Females (n = 8): total length, 9.24 – 12.50; males (n = 6): total length, 6.4 – 9.9. Two different variations are noticeable in the median cusp of some specimens of T. cladognatha. The median cusp is absent in specimens collected in the highlands in Minas Gerais state (
Tetragnatha cladognatha female, variation. A–D. Left chelicera without MC (
The holotype female of T. cladognatha from Rio de Janeiro city is considered presumed lost as all Bertkau’s spider types are, because none of them have ever been found in European collections. Considering that the distribution of T. cladognatha and T. argentinensis overlap in Brazil, with specimens of both species in Rio de Janeiro state (the type-locality of T. cladognatha), we consider the designation of a neotype necessary to clarify the taxonomic status of this species and therefore avoid possible misidentifications with T. argentinensis. Even though the original illustrations depicting the median cusp (
Mature males and females of T. cladognatha were collected in all months except June, but with much fewer specimens in the winter (also July and August). There seems to occur some plasticity in the life cycle of this species, despite a large percentage of mature specimens collected during late summer/early spring. Original labels of the specimens and our personal observations in the field suggest an affinity of this species with water courses, as it was hand collected along rivers as informed by the original labels, “manually collected in Camorim river” or in insect traps “malaise traps” and “light traps”.
Holotype
male, Sipapo River and Orinoco River confluence (05°04'04.7"N, 67°47'37.4"W, Amazonas, Venezuela), 27.xii.2002, OM Villarreal leg. (
The male of this new species is similar to T. tenuissima considering abdomen, chelicerae and pedipalp morphology. Both share a slender abdomen, laterally with five black patches, chelicerae with centrally placed ‘a’, large and bulky Gu apart from the extremely elongated ‘T’ (visible in lower view) by very large gap and pedipalps with filiform embolus not enfolded by the conductor and small triangular paracymbium (Figs
Tetragnatha amazonica sp. nov. male (
Male (based on holotype
Measurements. Total length 9.4. Carapace 2.1 long, 1.1 wide. Abdomen 7.3 long, 1.1 wide. Left chelicera 2.2 long, 0.4 wide. Leg formula I–II–IV–III. Leg I: femur 8.0, patella 0.8, tibia 8.3, metatarsus 9.2 and tarsus 1.9. Leg II: patella + tibia 4.9. Leg III: patella + tibia 1.6. Leg IV: patella + tibia 4.9.
Female. Unknown.
The specific epithet “amazonica” means “from Amazon” in Latin, referring to the type-locality in Venezuela and the Amazon Forest biome.
Only known from type-locality in Amazonas, Venezuela (Fig.
The single male holotype was collected in the summer (December). No information about habitat preferences were given on the original label.
Holotype
male, Lebon Régis (26°37'45.0"S, 54°06'48.0"W, Santa Catarina, Brazil), 15.vii.2006, R Lignau leg. (
Brazil – Rio Grande do Sul • 1 male, Cachoeira do Sul: Cordilheira, 30°13'S 52°50'W, 09.ix.1992, RG Buss leg. (
Tetragnatha cristata sp. nov. most resembles T. oncognatha sp. nov. and T. jaculator by its similar small cylindrical body and small chelicerae, a small ‘a’ and long distalward projected ‘T’ (Figs
Tetragnatha cristata sp. nov. male holotype (
Tetragnatha cristata sp. nov. male SEM photos. A, B. Left chelicera (
Male (holotype
Measurements. Total length 5.1. Carapace 1.5 long, 0.9 wide. Abdomen 3.7 long, 0.8 wide. Left chelicera 0.9 long, 0.3 wide. Leg formula I–II–IV–III. Leg I: femur 4.7, patella 0.6, tibia 5.1, metatarsus 5.3 and tarsus 1.4. Leg II: patella + tibia 2.9. Leg III: patella + tibia 1.2. Leg IV: patella + tibia 1.6.
Female. Unknown.
The specific Latin epithet “cristata” is an adjective meaning “with a crest or ridge”, and refers to the large crest between the two first teeth at the lower row of the male cheliceral furrow.
Males (n = 8): total length, 4.16 – 5.79. Males can have three additional lower teeth in the chelicerae, decreasing in size after L2 (e.g., Fig.
Mature specimens of T. cristata sp. nov. were collected in the hottest months of the year: January, February, March, September, October, November and December, pointing to a possible early summer/late spring maturity. Only one specimen was collected in July, during winter. No information on habitat preferences was provided in the original labels.
Holotype
male, Torres (29°20'06.0"S, 49°43'37.0"W, Rio Grande do Sul, Brazil), 26.iii.2006, ELC da-Silva leg. (
Males of Tetragnatha didorata sp. nov. resembles T. tenuissima and T. amazonica sp. nov. considering the elongated slender abdomen; T. bogotensis considering cheliceral morphology as both share long and straight ‘t’, and T. renatoi sp. nov. considering their pedipalp morphology with large subquadrate paracymbium (Fig.
Tetragnatha didorata sp. nov. male (
Male (holotype
Measurements. Total length 9.0. Carapace 2.5 long, 1.4 wide. Abdomen 6.6 long, 1.0 wide. Left chelicera 2.4 long, 0.6 wide. Leg formula I–II–IV–III. Leg I: femur 7.1, patella 0.9, tibia 6.8, metatarsus 7.5 and tarsus 1.6. Leg II: patella + tibia 4.4. Leg III: patella + tibia 1.7. Leg IV: patella + tibia 4.9.
Female. Unknown.
The specific epithet “didorata” is the compound latinized form of the Greek words: “di” meaning “two” and “dory, dorata” meaning “spear”, referring to the spear-like shape of the thin and long apophysis and the elongated and pointed ‘t’ at the upper side of the male chelicerae.
Males (n = 3): total length, 7.0 – 9.0. Little variation in colour pattern.
This species is mainly found at Paraná, Santa Catarina and Rio Grande do Sul, in the South region, but it was also collected in Pará state, in the North region, all in Brazil (Fig.
All specimens of T. didorata sp. nov. were collected during the autumn (late March, April and May) and the beginning of winter (July). No information on habitat preferences was given on the original labels of this species.
Tetragnatha laboriosa
Hentz, 1850: 27, plate 4, fig. [male syntype destroyed; male neotype designated by
Argentina – • Tetragnatha americana: one female, Río Santa Cruz, Santa Cruz, Patagonia (
See the section on T. nitens for additional information. Some of the specimens
Tetragnatha extensa (Linnaeus, 1758): Nicolet, 1849: 516, plate 4, figs 5, 5a–d (female, misidentified).
Eugnatha nitens
Tetragnatha nitens:
Tetragnatha labialis
Tetragnatha labialis:
Tetragnatha americana Simon, 1896: CV–CVI (sex?), New Synonymy.
Tetragnatha labialis Simon, 1896: CVII (sex?); 1902: 25; 1904: 94.
Tetragnatha americana: Simon, 1905: 10 (male, female, misidentified).
Tetragnatha americana: Unspecified number of syntypes from Peñaflor, Santiago, Chile, Lataste Coll.,
Chile – • 1 male from Punta Arenas (T. americana: Simon det.,
Tetragnatha americana was a new name
Despite
The type-series of T. americana Simon, 1896 is therefore composed of the specimens from Peñaflor examined by
Nicolet’s description focused on the shape and size of structures such as carapace, eyes, abdomen, chelicerae and pedipalps, but did not include precise details on chelicerae and genital morphology to allow species identification. Fortunately, he also provided relatively good drawings (
We were able to analyse all the specimens currently present in the
Tetragnatha nitens under T. americana, male. A. Left chelicera, inner view; B. Chelicerae, slanted lower view.
As mentioned above, the only species dealt with by
Holotype
male, Rancho Queimado (27°40'22.0"S, 49°01'19.0"W, Santa Catarina, Brazil), 09–13.x.1995, AA Lise leg. (
Brazil – Rio Grande do Sul • 1 female, Novos Cabrais, 29°44'06.0"S, 52°56'52.0"W, 27.i.2010, RG Buss leg. (
Males of T. oncognatha sp. nov. share with T. cristata sp. nov. and T. jaculator similar small-sized cylindrical bodies and small chelicerae, with ‘a’ small sized and ‘T’ long distalward projected (Figs
Tetragnatha oncognatha sp. nov. male holotype (
Tetragnatha oncognatha sp. nov. female paratype (
Tetragnatha oncognatha sp. nov. SEM photos. A, B. Male left chelicera; A. Upper view (
Male (holotype,
Measurements. Total length 6.1. Carapace 2.0 long, 1.3 wide. Abdomen 4.2 long, 1.1 wide. Left chelicera 1.2 long, 0.4 wide. Leg formula I–II–IV–III. Leg I: femur 2.9, patella 0.8, tibia 4.9, metatarsus 4.1 and tarsus 0.7. Leg II: patella + tibia 3.8. Leg III: patella + tibia 1.6. Leg IV: patella + tibia 2.4.
Female (paratype
Measurements. Total length 8.5. Carapace 2.5 long, 1.4 wide. Abdomen 6.0 long, 1.4 wide. Left chelicera 1.1 long, 0.5 wide. Leg formula I–II–IV–III. Leg I: femur 4.4, patella 0.8, tibia 5.1, metatarsus 5.4 and tarsus 1.3. Leg II: patella + tibia 3.5. Leg III: patella + tibia 1.6. Leg IV: patella + tibia 3.1.
The specific Greek epithet “oncognatha” refers to the gibbous, inflated chelicerae of both sexes, and is composed of the latinized form of the Greek “onkos” meaning “tumour, swell”, and “gnatha” meaning “mouthpart, chelicera”.
Males (n = 6): total length, 4.2 – 6.2. Male L3 may be absent, increasing the length of the gap (Fig.
The distribution of this species ranges from Itatiaia in South-centre Rio de Janeiro state, through Rancho Queimado in Centre-east Santa Catarina state, to Guaíba in South-centre and Viamão in Northeast Rio Grande do Sul state, all in Brazil (Fig.
Mature males and females of T. oncognatha sp. nov. were collected in January, March, May, July, August, and October to December, therefore the species does not seem to have a specific maturity period. No information on habitat preferences was provided on the original labels.
Holotype
female, São Francisco de Paula, Potreiro Velho (29°24'47.9"S, 50°15'36.8"W, Rio Grande do Sul, Brazil), 05–08.xii.1996, AA Lise leg. (
Tetragnatha pradoi sp. nov. seems similar to T. nitens, as both species share very elongated and bulky bodies, with abdomen much wider anteriorly, and similar chelicerae (Fig.
Tetragnatha pradoi sp. nov. female. A–G. Holotype female (
Female (based on holotype
Measurements. Total length 11.1. Carapace 2.6 long, 1.5 wide. Abdomen 8.7 long, 2.1 wide. Left chelicera 1.8 long, 0.6 wide.
Male. Unknown.
The specific epithet “pradoi” is a patronym honouring André Wanderley do Prado, work-colleague and friend of the authors, who gave a great deal of support throughout the development of all manuscripts on Tetragnatha.
Tibia, metatarsus and tarsus of the legs of the holotype were missing and consequently not measured.
Females (n = 3): total length, 8.2 – 11.1. Specimens do not conspicuously vary in colouration.
The only three females of T. pradoi sp. nov. we examined were collected in February and December. No information on habitat preferences was provided on the original labels.
Nomina dubia
The types of the following species are immature or presumed lost. Therefore, we are not able to correctly recognize the species. We cannot precisely identify them, nor clearly diagnose them in relation to other Tetragnatha. We considered a species as nomen dubium whenever its type-series was lost and original illustrations and descriptions were not very diagnostic, or when immatures could not be associated with adults.
Tetragnatha bishopi
Tetragnatha bishopi:
Tetragnatha bishopi: Subadult female holotype from Demerara-Mahaica, Tibicuri-Cuyahà, Guyana, x.1931, Coll. Beccari (
This species was described by
Tetragnatha linearis
Tetragnatha linearis:
Tetragnatha linearis: Adult female syntypes from Chile, Nicolet? Coll.,
Tetragnatha similis
Tetragnatha similis:
Tetragnatha similis: Female and adult? male syntypes from “Central Provinces”, Chile, Nicolet? Coll.,
Tetragnatha sternalis
Tetragnatha sternalis: Adult males and females syntypes from several localities in Chile, especially females from Llanquihue province, Nicolet? Coll.,
In the same book in which
Sixteen years later,
Tetragnatha is a very speciose genus with 321 valid species/subspecies after this work and is among the most common and widespread spiders in the world (
The results observed in
Considering the large number of species world-wide, a global scale taxonomic study on Tetragnatha is almost impossible. However, there have been many country- to continental-scale revisions, the first of which covered North America (
In South America, no taxonomic revision was previously carried out before the PhD thesis of the senior author (
We thank (in no particular order) all curators and technicians that sent specimens for this study or that received PdSC during visits to their collections: Antonio Brescovit (