Tetragnatha pradoi, Castanheira & Baptista & Oliveira, 2022

Castanheira, Pedro de Souza, Baptista, Renner Luiz Cerqueira & Oliveira, Francisca Samia Martins, 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), pp. 175-210 : 175

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Tetragnatha pradoi

sp. nov.

Tetragnatha pradoi sp. nov.

Figs 18 View Figure 18 , 19 View Figure 19


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. (MCTP 14123). Paratypes: Argentina - Buenos Aires • 2 females, Sierra de la Ventana, Hotel Provincial, 38°08'17.5"S, 61°48'02.6"W, 18.ii.1973 (MACN-AR 24550).


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. 18A, B View Figure 18 , Castanheira et al. 2019, fig.15A, B). Differently from T. nitens , however, T. pradoi sp. nov. has a short tail behind the spinnerets and AXu of the chelicerae is much more elongated, Gu and U2 slightly closer and fangs with an outer cusp and an inner cusp (differing from the basal cusp of T. nitens ) (Fig. 18A-E View Figure 18 ; Castanheira et al. 2019, figs 15A-I, 16B). Also, the genital fold of this new species is the longest within Tetragnatha , even longer than that in T. mandibulata , identifying this species from all other in the genus (Fig. 18G View Figure 18 ).


Female (based on holotype MCTP 14123): Carapace elongated, flattened and orange-brown, with two dark parallel lines from eyes, passing through fovea towards posterior rim (Fig. 18A View Figure 18 ). Labium l longer than wide and light brown. Sternum oval and light brown. AME and PME almost touching, and ALE and PLE touching (Fig. 18A View Figure 18 ). Legs very long, orange-brown (Fig. 18A, B View Figure 18 ). Chelicera paturon around 3.9 × longer than wide, 1.3 × shorter than carapace and around 20° from body median line, with orange-brown colour hue, (Fig. 18A, C-F View Figure 18 ). AXu elongated, pointed and distalward projected, with very large basis (Fig. 18C, D View Figure 18 ). Upper row with eight teeth distalward projected (Fig. 18C, D View Figure 18 ): Gu long and pointed, similar to AXu. but with narrow basis, and located on fang furrow, apart from U2 by a moderate gap; U2 similar to Gu and apart from it and U3 by moderate gaps of the same length; U3-U8 pointed and decreasing in size. AXl absent (Fig. 18D, E View Figure 18 ). Lower row with eleven teeth distalward projected (Fig. 18D, E View Figure 18 ): Gl elongated, pointed and sclerotized, apart from L2 by a large sclerotized gap; L2 with a moderate size, pointed and slightly displaced from the row itself, apart from L3 by a small gap; L3-L11 pointed and decreasing in size, L10 and L11 extremely reduced. Cheliceral fang thick, anteriorly enlarged and uniformly tapering to its tip, bearing a large triangular outer cusp near its basis and a small inner cusp on its first third (Fig. 18C-F View Figure 18 ). Abdomen almost 3.2 × longer than carapace, cylindrical and anteriorly bulging, with beige colour hue, covered by sparse guanine crystals, and having a small tail after the spinnerets (Fig. 18A, B View Figure 18 ). Genital fold extremely elongated, around 1.7 × longer than wide, narrowed midway, with a rounded posterior rim, and light brown colour hue (Fig. 18G View Figure 18 ). Internal genitalia with two rounded sclerotized and longer than wide spermathecae, connected to a large uterus externus and a cylindrical central membranous sac (Fig. 18H View Figure 18 ).

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 " Tetragnatha 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.


From Brazil (Rio Grande do Sul state) to Argentina (Buenos Aires province) (Fig. 19 View Figure 19 ).

Life history and habitat preferences.

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.