Research Article |
Corresponding author: Pedro de Souza Castanheira ( pedrocastanheira.bio@gmail.com ) Academic editor: Danilo Harms
© 2019 Pedro de Souza Castanheira, Renner Luiz Cerqueira Baptista, Daniela Dos Passos Pizzetti, Renato Augusto Teixeira.
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:
de Souza Castanheira P, Baptista RLC, Pizzetti DDP, Teixeira RA (2019) Contributions to the taxonomy of the long-jawed orb-weaving spider genus Tetragnatha (Araneae, Tetragnathidae) in the Neotropical region, with comments on the morphology of the chelicerae. Zoosystematics and Evolution 95(2): 465-505. https://doi.org/10.3897/zse.95.36762
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We newly diagnose, illustrate, and clarify the distribution ranges of six of the most common and broadly distributed species of Tetragnatha Latreille, 1804 found in the Neotropical region. Twenty new junior synonyms from around the world are included, nine for T. bogotensis Keyserling, 1865, four for T. mandibulata Walckenaer, 1841, three for T. keyserlingi Simon, 1890, three for T. nitens (Audouin, 1826), and one for T. elongata Walckenaer, 1841. Tetragnatha vermiformis Emerton, 1884 is newly recorded from South America. The Argentine T. major Holmberg, 1876 and T. riparia Holmberg, 1876 are considered nomina dubia. Finally, we discuss the terminology of the structures of the chelicerae to establish a coherent nomenclature for teeth and fang cusps.
Biodiversity, Araneoidea, Systematics, Tetragnathinae
The long-jawed spider genus Tetragnatha Latreille, 1804 (family Tetragnathidae) comprises 349 species, 67 of which restricted to the Neotropics (
Although no complete revision is available for Tetragnatha, species redescriptions and local revisions are frequent. The first revisionary papers on the genus addressed species from North America (
In this paper, we analyse most of the widespread species of Tetragnatha in the Neotropical region. We propose 20 new synonymies for five of them and include new records from South America for one species previously known from Asia and introduced in North and Central America. We also provide new diagnoses, illustrations, and many new distribution records. Furthermore, we consider two species from Argentina as nomina dubia.
The taxonomic summary for all species is abbreviated to save space, including only the information we consider most relevant. See the
Structures were cleaned using a Cristofoli Ultrasonic Cleaner and positioned in 70% ethanol gel or glass spheres for automontage photographs and measurements. Images were taken with a Leica DFC450 camera mounted on a Leica M205C stereoscope microscope (Leica Camera AG, Wetzlar, Germany) at the Laboratório de Entomologia, Universidade do Brasil/Universidade Federal do Rio de Janeiro. All images were edited with Adobe Photoshop CS5.1 and figures were prepared using Adobe Illustrator CS5.1 (Adobe Inc., San Jose, California, USA). Measurements are given in millimeters. The position of teeth and fang cusps (upward, downward, distalward, and basalward) was noted when the chelicerae were attached to the body. The genital fold length was measured from the inner angle of book-lung plates to the posterior rim of the fold. The genital fold proportion is the comparison of its length versus the span between the outer angle of posterior rim of one book-lung plate to the outer angle of the other. Males were matched with conspecific females by cheliceral morphology and collection sites.
For scanning electron microscopy (SEM), samples were critically point dried, mounted on adhesive copper tape (Electron Microscopy Sciences, EMS 77802), affixed to a stub and sputter-coated with Au-Pd for examination under high vacuum with a JEOL JSM-6510 microscope at Laboratório de Imagens, Instituto de Biologia, Universidade Federal do Rio de Janeiro; a Philips XL 30 Field Emission ESEM at the Centro de Microscopia e Microanálises, Pontíficia Universidade Católica do Rio Grande do Sul, and a JEOL JSM-6390LV at Centro de Microscopia, Fundação Oswaldo Cruz.
To clear female genitalia, we used a borax solution (
Maps were produced using QGIS v. 2.14 software and geographic coordinates were extracted from original labels. When no coordinates was available, the closest nearby area coordinates were obtained from Global Gazetteer v. 2.3 (http://www.fallingrain.com/world/index.html) or Google Earth v. 9.1.39.1 (https://earth.google.com/web/).
Cited institutions and their acronyms are:
IBSP Instituto Butantan, Brazil (A. Brescovit);
MCTP Museu de Ciência e Tecnologia da Pontíficia Universidade Católica do Rio Grande do Sul, Brazil (R. Teixeira);
MLPC Mello-Leitão’s private collection, now at Museu Nacional, Universidade do Brasil/Universidade Federal do Rio de Janeiro, Brazil (A. Kury);
NMV Museums Victoria, Australia (K. Walker);
ZMB Museum für Naturkunde, Humboldt-Universität, Germany (J. Dunlop);
Abbreviations used below for the 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 (new terminology). Okuma applied different names to this structure: excrescence (1987) and posterior cusp (1992).
CB cheliceral bulge, a protruding area between the two rows of teeth, near the base of the fang (new terminology).
CRu cheliceral crest, a protruding marked area on the upper row of teeth (new terminology).
CRl cheliceral crest, a protruding marked area on the lower row of teeth (new terminology).
Gu
guide tooth of the upper (or dorsal) row (follows
Gl
guide tooth of the lower (or ventral) row (follows
IC
inner cusp of fang (follows
L2-n teeth on the lower row numbered from the distal end after Gl.
OC outer cusp of fang (present in some species) (new terminology).
rsu
remaining proximal teeth on the upper row of males after T (
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.
Abbreviations for male and female genitalia, male palps:
E embolus;
C conductor;
Y cymbium;
P paracymbium
K knob at the ectal side of paracymbium (new terminology),
L translucent lobe at the mesal side of paracymbium,
N notch at the apex of paracymbium.
Female genitalia:
GF genital fold;
Sp spermatheca;
CS central membranous sac.
Genus Tetragnatha Latreille, 1804
Tetragnatha bogotensis
Tetragnatha andina
Taczanowski 1878: 144, pl. 1, fig. 2 (♀);
Tetragnatha boydi
O.
Tetragnatha peninsulana
Tetragnatha praedator
Tetragnatha mandibulata bidentata
Tetragnatha eremita
Tetragnatha nitens
Tetragnatha bemalcuei
Tetragnatha ramboi
Tetragnatha haitiensis
Tetragnatha nitens kullmanni
Tetragnatha infuscata
Tetragnatha boydi praedator
Tetragnatha bogotensis: COLOMBIA: ♀♀ syntypes, “Nova Granada” [surely Bogotá], 1859–1863? Alexander Lindig leg., not located, probably lost. Tetragnatha andina: PERU: ♂♂, ♀♀ syntypes, “Amable Maria” [surely province of Tarma, region of Junín] (38 syntypes, Coll. K. Jelski,
Males of T. bogotensis are similar to T. nitens (Audouin, 1826) and share chelicerae with an elongated ‘a’, and AXu and ‘t’ extremely elongated and distally bent. AXu and ‘t’ differ as follows: thick and triangular in T. bogotensis (Figs
Tetragnatha bogotensis Keyserling, 1865, male (
Females are similar to T. nitens and also T. mandibulata Walckenaer, 1841, sharing: bulky body, wide and pointed at the terminal end (Figs
Tetragnatha bogotensis Keyserling, 1865, female. A. Dorsal habitus (
Tetragnatha bogotensis Keyserling, 1865, SEM photos. A. Left male palp, mesal view (MCTP 4299); B. Left male chelicera, upper view (MCTP 4299); C. Left female chelicera, upper view (MCTP 4299); D. Left male palp paracymbium, ventral view (
The first author of this paper visited three collections with type material by Keyserling:
Tetragnatha boydi has been redescribed and illustrated many times (see
Tetragnatha praedator
Tetragnatha bemalcuei was described by
We also note that several species previously considered junior synonyms of T. nitens should be newly synonymised with T. bogotensis. For example,
Tetragnatha eremita Chamberlin, 1924 was based on a male holotype from Baja California, Mexico.
Furthermore,
Males (n = 18): total length, 7.36–11.60; females (n = 17): total length, 7.52–11.76. The gap between Gu and U2 is variable in males of this species and can have almost the double of the length of the specimen illustrated.
This species is widespread in the Neotropics and Mexico, but potentially north into the southern United States; it also occurs in the Old World, with records from Africa, Yemen, India, Nepal, and China (Fig.
Tetragnatha elongata
Tetragnatha tropica
O.
Tetragnatha elongata: GUADELOUPE: ♂ ♀ syntypes, lost; UNITED STATES OF AMERICA: ♂ neotype, Raleigh, North Carolina (Coll. C. S. Brimley, 21–31.viii.1944,
Females of T. elongata can be distinguished from all other Neotropical species by their elongated body, abdomen anteriorly enlarged and much narrower posteriorly, large chelicerae with an outer cusp (OC), and a short genital fold (Figs
Male chelicerae of T. elongata are similar to those of T. laboriosa Hentz, 1850, insofar as sharing elongated apophyses with excavated tips, elongated and robust ‘T’, and long Gl, the last as the longest teeth of both lower rows (Figs
Tetragnatha elongata Walckenaer, 1841, male (MCTP 28045). A. Dorsal habitus; B. Lateral habitus; C. Ventral habitus; D–G. Left chelicera: D. Upper view; E. Inner view; F. Lower view; G. Outer view; H–K. Left male palp: H. Mesal view with tibia; I. Mesal view detail; J. Dorsal view; K. Ventral view (paracymbium). Scale bars: 2 mm (A, B, C); 1 mm (D, E, F, G, H); 0.5 mm (I, J, K).
Tetragnatha elongata Walckenaer, 1841, female. A. Dorsal habitus (MCTP 28045); B. Lateral habitus (MCTP 28045); C–F. Left chelicera (MCTP 28045): C. Upper view; D. Inner view; E. Lower view; F. Outer view; G, H. Genital area: G. Genital fold, ventral view (MCTP 28045); H. Internal genitalia, cleared, ventral view (MCTP 28306). Scale bars: 5 mm (A, B); 1 mm (C, D, E, F); 0.5 mm (G); 0.2 mm (H).
Tetragnatha elongata Walckenaer, 1841, SEM photos. A. Left male chelicera, upper and lower views (MCTP 0229); B. Left female chelicera, upper view (MCTP 43306 ex 0370); C. Left male palp, mesal view (MCTP 0229); D. Left male palp conductor detail and pleats, mesal view (MCTP 0229); E. Tip of conductor detail, dorsal view (MCTP 43306 ex 0370); F. Left male palp paracymbium, ventral view (MCTP 0229); G. Epiandrous field, ventral view (MCTP 43306 ex 0370). Scale bars: 1 mm (A); 0.5 mm (B, C); 0.2 mm (D); 0.01 mm (E); 0.3 mm (F); 0.05 mm (G).
Tetragnatha tropica was described from a single female from Guatemala (Menché, currently Atxchilan, near the Mexican border), not located in
We also highlight that
Males (n = 8): total length, 7.20–13.45; females (n = 15): total length, 8.88–13.90.
Tetragnatha elongata is a very common species in the Nearctic and Neotropical regions, recorded from Canada (
Tetragnatha mandibulata:
Tetragnatha mandibulata
?: L.
Tetragnatha keyserlingi
Tetragnatha mandibulata:
Tetragnatha maxillosa
Tetragnatha kochi
Tetragnatha japonica
Tetragnatha conformans
Tetragnatha propioides
Tetragnatha ethodon
Tetragnatha keyserlingi: COLOMBIA [Neu Granada]: ♂ ♀ syntypes, not located. Tetragnatha maxillosa: INDONESIA: ♀ syntype, Java, not located; SINGAPORE: ♂ ♀ syntypes (Coll. Workman), not located. Tetragnatha kochi: ♂ ♀ syntypes, FIJI (Ovalau), not located; TONGA, not located; SAMOA (Upolu) [2♀ sub T. mandibulata, Mus. Godeffroy collection, 1869 (
Males of T. keyserlingi are similar to T. elongata. Both species have a long body, a very long paturon, AXl and Gl placed on a common base and displaced to a lower position than the remaining lower teeth, and conductor tips not extended in tail-like projections (Figs
Tetragnatha keyserlingi Simon, 1890, male (
Female chelicerae have elongated Gu, U2, and U3, where Gu is set apart from U2 by a very large gap and is located on an upper crest (CRu) (Figs
Tetragnatha keyserlingi Simon, 1890, female. A. Dorsal habitus (
Tetragnatha keyserlingi Simon, 1890, SEM photos. A. Left male chelicera, upper and lower views (MCTP 43319 ex 6944); B. Left female chelicera, upper and lower view (MCTP 14749); C. Left male palp, mesal view (MCTP 43319 ex 6944); D. Left palp conductor tip, mesal view (
This species is widespread in the Old World tropics and has been cited and illustrated many times under T. maxillosa (
Tetragnatha keyserlingi was named by
Tetragnatha keyserlingi was also recorded from Java (Indonesia) (
We agree with
Another mismatching of T. keyserlingi and T. nigrita occurred with the type series of T. cliens, as observed by
Finally, T. ethodon was described by
Males (n = 11): total length, 5.29–7.28; females (n = 14): total length, 6.59–9.03. In
Pantropical, including Africa, Asia, Polynesia, Central America, and Brazil (Fig.
Tetragnatha mandibulata
Tetragnatha confraterna
Tetragnatha necatoria
Tetragnatha petrunkevitchi
Tetragnatha petrunkevitchi:
Tetragnatha infuscata
Tetragnatha mandibulata: GUAM: ♂♀ syntypes, Mariana Archipelago, not located. Tetragnatha confraterna: COSTA RICA: ♂♀ syntypes, Machuca (Coll. P. Biolley); Escazii (Coll. J. F. Tristan); 3♂ 1♀ 1 immature, Tiribi (Coll. J. F. Tristan,
For females, see the extended diagnosis of T. bogotensis. Males can be distinguished by the elongated body (Fig.
Tetragnatha mandibulata Walckenaer, 1841, male (
Tetragnatha mandibulata Walckenaer, 1841, female. A. Dorsal habitus (
Tetragnatha mandibulata Walckenaer, 1841, SEM photos. A. Left male chelicera, upper view (
We identified many specimens of T. mandibulata from northern to southeastern Brazil. Unfortunately we were not able to study the type material of this species from Guam. It was not available at the
After comparing our specimens with illustrations from redescriptions, we noticed close similarities between T. mandibulata and T. confraterna (Fig.
Tetragnatha necatoria Tullgren, 1910 was based on a male specimen from the Pare Mountains in Tanzania. After studying one photo of the upper row of teeth of this male holotype and the original illustration of the distal part of the left chelicera of this species (Fig.
We received photos of one of the many specimens of T. petrunkevitchi Caporiacco, 1947 from Potaro and Georgetown, Guyana. This female (
Finally, based on photos of the male holotype of T. infuscata from the Seychelles (
Males (n = 6): total length, 7.12–11.89; females (n = 20): total length, 7.54–11.63.
Known from Africa, Asia, Australia, Central America, the Caribbean, and South America (Brazil and Guyana) (Fig.
Eugnatha nitens
Eugnatha pelusia
Tetragnatha nitens
Tetragnatha peruviana Taczanowski 1878: 142, pl. 1, fig. 1a–c (♂ ♀) syn. nov.
Tetragnatha andina
Taczanowski 1878: 144, pl. 1, fig. 2 (♀);
Tetragnatha peninsulana
Tetragnatha eremita
Tetragnatha decipiens
Tetragnatha haitiensis
Tetragnatha tullgreni
Tetragnatha caporiaccoi
Tetragnatha nitens kullmanni
Tetragnatha nitens: EGYPT: ♂ ♀ syntype, Rosetta, Markaz Rasheed, lost (
See the extended diagnosis under T. bogotensis for the diagnostic characters of T. nitens.
Tetragnatha nitens (Audouin, 1826), male (MCTP 1426). A. Dorsal habitus; B. Ventral habitus; C–F. Left chelicera: C. Upper view; D. Inner view; E. Lower view; F. Outer view; G–J. Left male palp: G. Mesal view. H. Dorsal view; I. Ventral view (paracymbium); J. Paracymbium detail, ventral view. Scale bars, 2 mm (A, B); 1 mm (C, D, E, F); 0.5 mm (G, H, I); 0.2 mm (J).
Tetragnatha nitens was first described from Egypt, but its syntypes are lost according to
Another lapsus occurred with T. nitens kullmanni from Sardinia, Italy (
Mainly based on our observations of the morphology of the chelicerae, we propose three new synonymies for T. nitens: T. peruviana from Peru, T. decipiens from Paraguay, and T. caporiaccoi from Guyana. The type materials of all species were studied; for T. peruviana images from
Tetragnatha decipiens and T. caporiaccoi were described only from females, while descripitions of T. peruviana were based on males and females, with males described first, even though only females were illustrated. Females of the three species and males of T. peruviana clearly show the diagnostic characters of T. nitens (see Diagnosis above).
Males (n = 23): total length, 7.22–9.04; females (n = 30): total length, 7.42–11.44. The internal genitalia of females is also variable, with CS stalk shorter or longer than CS head, which places this structure at the same level or anterior to the spermathecae, which also vary in size (Fig.
Tetragnatha nitens (Audouin, 1826), female. A. Dorsal habitus (
Tetragnatha nitens (Audouin, 1826), SEM photos. A. Left male chelicera, upper and lower views (MCTP 1618). B. Left female chelicera, upper and lower views (MCTP 11555). C. Epiandrous field, ventral view (MCTP 1618). D. Left male palp, bulb detail, mesal view (MCTP 5985). E. Left male palp, mesal view (MCTP 5985); F. Left male palp paracymbium, ventral view (MCTP 5985). Scale bars: 1 mm (A, B); 0.1 mm (C); 0.5 mm (D, E, F).
This species was first described from Africa (Egypt), but it has a cosmopolitan distribution, with many new records from the Neotropics (Fig.
UNITED STATES OF AMERICA: ♂ lectotype, ♀ paralectotype (
Males and females of T. vermiformis are most similar to T. pallescens F. O. Pickard-Cambridge, 1903. Males have similar length and width of chelicerae (Figs
Tetragnatha vermiformis Emerton, 1884, male (
Females of both species have similar small, rounded and laterally bulging chelicerae (Figs
Tetragnatha vermiformis Emerton, 1884, female. A. Dorsal habitus (
Tetragnatha vermiformis Emerton, 1884, SEM photos (MCTP 43339 ex 11333). A. Left male chelicera, upper and lower views; B. Left female chelicera, upper and lower views; C. Left male palp, mesal view; D. Left palp conductor detail, mesal view; E. Male palp paracymbium, ventral view; F. Epiandrous field, ventral view. Scale bars: 0.5 mm (A, B, C); 0.05 mm (D); 0.1 mm (E); 0.02 mm (F).
Males (n = 4): total length, 6.29–7.29; females (n = 7): total length, 6.99–10.98. The spermathecal lobes are variable in size and form. Both lobes may be more regularly cylindrical and the external lobe may be much smaller than the inner one (
Temperate and tropical Asia, North and Central America, newly recorded from South America (Brazil) (Fig.
Tetragnatha major and T. riparia were described by
In the literature the importance of the chelicerae for correctly diagnosing species has often been ignored. Old publications (e.g.
Unfortunately, Okuma and Gillespie lacked consistence on their nomenclature. For example, Okuma called “U2” the more elongated tooth on the upper row (
The inconsistent terminology for chelicerae in Tetragnatha has hampered the recognition of homologies between species, shown by the lack of such characters in family phylogenies including morphological data (
In Tetragnatha, adults normally bear guide teeth on upper (Gu) and lower rows (Gl). It is the usually robust first tooth on each margin (e.g. Figs
Males usually have specialized teeth, longer, more conspicuous, and more numerous than in females. There is an apophysis (spur) on the upper surface, which varies in shape and position, from the middle portion on distal part of paturon (Figs
In relation to fangs, we call the massive pointed projection placed at lower side and near fang basis the basal cusp (BC) (Figs
We also introduce new terminology for modifications of the paturon. Some have a rounded elevated cheliceral bulge (CB) in the area between both rows of teeth (Figs
Embolous and conductor tip detail, dorsal view, SEM photos. A. T. bogotensis (MCTP 4299); B. T. elongata (MCTP 43306 ex 0370); C. T. keyserlingi (MCTP 43319 ex 6944); D. T. mandibulata (
Junior synonyms mentioned on the manuscript. A–G. T. bogotensis synonyms chelicerae, ♂ upper view, ♀ lower view: A. T. andina, ♀ syntype; B. T. peninsulana, ♀ syntype; C. T. boydi praedator, ♂ syntype; D. T. eremita, ♂ holotype; E. T. bemalcuei, ♀ holotype; F. T. ramboi, ♂ lectotype; G. T. haitiensis, ♀ holotype; H–M. T. keyserlingi synonyms, left chelicerae: H. T. kochi, ♀ syntype upper view; I–K. T. japonica (
Records of the material we analysed (circles), including the type localities of Neotropical junior synonyms cited in the text (stars and triangles). A. Tetragnatha bogotensis; B. Tetragnatha elongata; C. Tetragnatha keyserlingi (excluding Haiti); D. Tetragnatha mandibulata; E. Tetragnatha nitens; F. Tetragnatha vermiformis.
We thank all the curators already mentioned above in Methods and give special thanks to Laura Leibensperger (Department of Invertebrate Zoology, Museum of Comparative Zoology) for her effort in taking many of the photographs. Copyright of all her Original Photography is President and Fellows of Harvard College. We are also in debit to all who sent additional images of type material: Rachel Diaz-Bastin (