Tetragnatha amazonica sp. nov.

Figs 6, 19

Type-material.

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. (MNRJ 1571).

Diagnosis.

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 6A-I; Castanheira and Baptista 2020, figs 12A-I, 14A, B, E-G, 15A). However, T. amazonica sp. nov. can be easily differentiated from T. tenuissima by chelicerae with much thinner ‘a’, absent ‘sl’, ‘T’ with curved tip, presence of CRu and CRl, Gl straight and apart from L2 by much larger gap and pedipalps with embolus apart from conductor since its middle portion and longer paracymbium with notch longer and distalward projected (Fig. 6D-J).

Description.

Male (based on holotype MNRJ 1571): Carapace elongated, slightly elevated anteriorly and light brown (Fig. 6A, B). Labium longer than wide and reddish brown (Fig. 6C). Sternum oval and light brown, with no marks or contour (Fig. 6C). Eyes with ALE and PLE touching (Fig. 6A). Legs very elongated and yellow, legs I and II slightly darker (Fig. 6A-C). Chelicera paturon approximately 4.3 × longer than wide and 1.15 × smaller than carapace, heavily curved outwards, around 55° from body median line, very thick and with orange hue (Fig. 6A, D-G). ‘a’ tubular, with small dent on inner margin of its tip and located in midway position of paturon (Fig. 6D, E, G). AXu and ‘t’ absent (Fig. 16D, E). Upper row with eight teeth distalward projected (Fig. 6D, E): Gu very long and thick, with very broad basis and apart from ‘T’ by a conspicuous upper crest (CRu) on large gap; ‘sl’ absent; ‘T’ conspicuous and elongated, sclerotized, and pointed with a curved tip; ‘rsu’ composed of six pointed teeth, decreasing in size and apart by regular small gaps. AXl absent (Fig. 6E, F). Lower row with eight teeth (Fig. 6E, F): Gl triangular, very thick, sclerotized, straight and bearing rounded blunt tip, apart from L2 by large gap following extremely sclerotized dark lower crest (CRl), that goes slightly beyond L2; L2 also very thick, sclerotized, and straight (or slightly basalward projected) with large tip and apart from L3 by smaller gap than Gl-L2; ‘rsl’ composed of extremely reduced teeth, apart from one another by small gaps. Cheliceral fang thick, uniformly tapering to its tip, slightly wavy from midway and closing between teeth rows (Fig. 6D-F). Abdomen approximately 2.6 × longer than carapace, slender, and pale beige, covered by sparse guanine crystals with five dusky dark patches on each size of dorsum (Fig. 6A-C). Pedipalps with extremely elongated cymbium, around 2.9 × longer than wide and rounded tibia, bearing wide basis and no apical constriction (Fig. 6H-J); tegulum approximately 1.4 × wider than long and inflated (Fig. 16H); conductor elongated, ribbon-like and distally wider, not enclosing embolus and ending in broad twisted tip (Fig. 6H, I); embolus filiform, basally thicker and enlarged, ventrally bending from mid-way and resting its slender tip on conductor (Fig. 6H, I); paracymbium short, only 2.3 × longer than wide, with transparent lobe occupying around 1/3 of its width, notch rounded and undivided, and knob large and triangular pointed (Fig. 6J).

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.

Etymology.

The specific epithet " Tetragnatha amazonica " means "from Amazon" in Latin, referring to the type-locality in Venezuela and the Amazon Forest biome.

Distribution.

Only known from type-locality in Amazonas, Venezuela (Fig. 19).

Life history and habitat preferences.

The single male holotype was collected in the summer (December). No information about habitat preferences were given on the original label.