Tobias caudatus Mello-Leitão, 1929

Machado, Miguel, Teixeira, Renato Augusto & Lise, Arno Antonio, 2015, Taxonomic notes on the crab spider genus Tobias Simon, 1895 (Araneae, Thomisidae, Stephanopinae), Zootaxa 4034 (3), pp. 565-576 : 567-570

Tobias caudatus Mello-Leitão, 1929

Figs 1–11

Tobias caudatus Mello-Leitão, 1929: 88 , figs 187–188.

Type material: Holotype (designated by Mello-Leitão, 1929): female, Tijuca [22°57'31.38"S, 43°16'38.56"W, Rio de Janeiro, Rio de Janeiro, Brazil] ( MNHN 26036).

Other material examined. PUERTO RICO: Mora : 1 female, 18°27'6.76"N, 66°59'15.86"O (A. Schwartz leg., 22 February 1965, MCZ 700). BRAZIL: Amazonas: 1 female, Benjamin Constant, 4°22'27.79"S, 70° 1'46.99"W (Parko leg., April 1942, MNRJ 2698). Bahia: 1 female, Itamaraju, 17°2'38.00"S, 39°31'48.00"W (J.S. Santos leg., 7 August 1978, MCN 10690). São Paulo: 1 female, Ilha de Búzios, 23°46'35.00"S, 45°21'10.00"W (Zoology department expedition field leg., October 1963, MZSP 11420). Paraná: 1 male, Morretes, 25°28'31.00"S, 48°49'45.00"W (A. A. Lise leg., 9–20 January 1995, MCTP 7092). Santa Catarina: Florianópolis, Reserva Biológica do Arvoredo, 27°17'0.00"S, 48°22'0.00"W, 1 female, 16 October 1993, 1 female, 14 October 1994, 1 female, 6 October 1995, all material leg. A.A. Lise ( MCTP 4082, 5120, 7593). Rio Grande do Sul: 1 female, Derrubadas, Parque Estadual do Turvo, 27°14'60.00"S, 53°52'0.00"W (R. Ott leg, 4–8 May 2004, MCN 38865); 1 female, Iraí, 27°10'60.00"S, 53°15'0.00"W (S. Scherer leg., 19 November 1975, MCN 8130); 1 female, same locality as previous specimen (A. A. Lise leg., 20 November 1975, MCN 8133); 1 female, Nonoai, Parque Estadual de Nonoai, 27°20'48.63"S, 52°45'59.67"W (A. A. Lise leg., 19–24 January 1989, MCN 13075); 1 female, São Borja, 28°11'2.00"S, 55°38'20.00"W (H. Bischoff leg., 10 November 1979, MCN 8670); 1 female, Itaara, 29°34'60.00"S, 53°46'60.00"W (E. L. C. Silva leg., 23 November 2006, MCTP 28508); 1 male, Santa Maria, Cidade dos Meninos, 29°40'41.58"S, 53°43'17.89"W (C. Kotzian & L. F. Indrusiak leg., 7 November 1995, MCTP 10470); 1 female, Novo Hamburgo, 29°41'0.00"S, 51° 7'60.00"W (C. J. Becker leg., 17 June 1986, MCTP 15170); 2 males, same locality as previous specimen (17 June 1988, MCTP 240); 1 female, São Leopoldo, 29°46'0.00"S, 51° 9'0.00"W (C. J. Becker leg., 19–30 July 1982, MCN 10645); 1 female, same locality as previous specimen (A. B. Bonaldo leg., 12 May 1992, MCN 24756); 1 female, Glorinha, 29°52'48.00"S, 50°47'45.00"W (A. B. Bonaldo leg., 14 July 2000, MCN 33052); 1 female, Triunfo, 29°55'60.00"S, 51°42'60.00"W (M. A. L. Marques leg., 28 November 1989, MCN 18999); 1 male, Eldorado do Sul, 30°6'41.38"S, 51°37'50.68"W (A. Braul & C. Aveiróz leg., 18–19 September 1993, MCTP 4133); 1 female, Cachoeira do Sul, 30°1'60.00"S, 52°53'60.00"W (R. G. Buss leg., 27 May 1995, MCTP 6100); 1 female, Porto Alegre, Parque Estadual Delta do Jacuí, 30°1'60.00"S, 51°12'0.00"W (I. Heidrich leg., 26 August 1999, MCN 31483); 1 female (8 July 1999, MCN 31337); 1 male, Viamão, 30° 4'60.00"S, 51° 1'60.00"W (N. J. Ferla leg., 8 December 1992, MCTP 2826); 1 female, same locality as previous specimen (A. Braul leg., 10 October 1993, MCTP 3933); 1 male, same locality as previous specimen (A. A. Lise leg., 17 December 1995, MCTP 8092); 1 male, São Sepé, 30°10'0.00"S, 53°34'0.00"W (E. C. Costa leg., 6 February 1994, MCTP 10246).

Diagnosis. Females of T. caudatus resemble those of T. pustulosus in the brownish body coloration ( Figs 1–2 ), presence of remarkable setiferous tubercles on femora I and II—the dorsal and lateral tubercles are long and conical, while the ventral tubercles are short and rounded. However, females of T. caudatus differ from T. pustulosus and other species of Tobias by the reddish coloration of the ventral setiferous tubercles of femora I and II ( Fig. 4 ), by the narrow median septum on epigynum, and by the lateral folds delimiting the median field ( Fig. 8 ). Males can be distinguished by yellowish granules on prosoma, yellow half-moon shaped spots on the dorsum of the opisthosoma ( Fig. 3 ), RTA canoe-shaped, deeper, with larger borders than in other species of Tobias and by the DTA with curvature directed upwards ( Fig. 11 ).

Description. Female (from Santa Catarina; MCTP 7593): Anterior eye row recurved and posterior row slightly procurve. Prosoma brown with irregular dark-brown spots on the dorsal and lateral regions ( Fig. 1 ). Posterior slope slightly lighter than other regions of the prosoma. Clypeus height 0.65. Chelicerae with three teeth on the promargin and two on the retromargin ( Fig. 5 ). Coloration of chelicera and palp as in prosoma. Sternum, endites and labium reddish-brown. Sternum covered by needle-shaped and feather-shaped setae, scutiform, with anterior margin concave. Endites rounded, with scarce setae on promargin and labium short. Cuneiform opisthosoma with anterior margin slightly concave and three posterior projections, being a pair of lateral projections with the apex directed forward, and a median projection rounded and long ( Fig. 1 ). Abdominal surface rough, granular, dark-brown on the dorsum and light-brown on the anterior lateral margins and along the median projection ( Fig. 1 ). Legs in transverse view square-like, with brown spotted coloration and distinct yellow parts at the distal portion of femur I and proximal portion of tibia I. All femora are covered with setiferous tubercles, with the biggest ones on femora I. The setiferous tubercles on the dorsum and lateral sides of the femora are long and conical, whereas those on the ventral portion of femora I and II are short and rounded and reddish-brown. Tibiae and metatarsi I and II have three pairs of ventral macrosetae. Tibiae, metatarsi and tarsi show a dorsal depression containing a group of trichobothriae and surrounded by many duster-shaped setae (sensorial pit) ( Fig. 6 ). Tarsi ending in scarce scopula. All tarsal claws strongly curved with the first tooth longer and stronger than the remaining teeth ( Fig. 7 ). Epigynum with lateral folds delimiting the median field, copulatory openings separated by a median septum, joined with the lateral folds in the anterior region ( Fig. 8 ). Copulatory ducts long with two pairs of kidney-shaped spermatecae, primary spermatecae are at least two times larger than the secondary pair, with porous surface ( Fig. 9 ). Measurements: eyes diameters and eyes interdistances: AME 0.17, ALE 0.18, PME 0.15, PLE 0.14, AME-AME 0.40, AME-ALE 0.20, PME-PME 0.54, PME-PLE 0.24. MOQ length 0.70, MOQ posterior width 0.65, MOQ anterior width 0.64; leg formula: 1243: leg I—femur 5.92/ patella 3.17/ tibia 3.84/ metatarsus 2.92/ tarsus 2.00/ total 17.85; II—5.92/ 3.25/ 3.42/ 2.50/ 1.34/ 16.43; III—2.50/ 1.75/ 1.75/ 1.34/ 0.83/ 8.17; IV— 2.58/ 1.84/ 2.08/ 1.58/ 1.08/ 9.16. Total length 15.42, prosoma length 5.92, width 5.75, opisthosoma length 9.50, clypeus height 0.78, sternum length 2.35, width 1.95, endites length 1.44, width 0.83, labium length 0.86, width 0.99.

Male (from Eldorado do Sul; MCTP 4133): Anterior and posterior eye rows as in female. Tegument above the ALE presents tiny horns ( Fig. 3 ). Prosoma coloration darker than in the female. Sternum, endites and labium as in female. Patterns of coloration of the opisthosoma as in female, albeit lighter. Lateral projections on the opisthosoma straight and slightly shorter than in females. Legs I and II reddish-brown with some dark spots. Dorsal and lateral setiferous tubercles of legs as in female, ventral tubercles absent. Legs shape and tarsal claw as in females. Palp with discoid tegulum with transversal furrow at seven o’clock position ( Fig. 10 ). Embolus long, filiform, emerging from tegulum at six o’clock position, running two and a half circles around the tegulum. RTA canoe-shaped, joined with DTA, which is hook-like, short, acute and curved upwards ( Fig. 11 ). Measurements: eyes diameters and eyes interdistances: AME 0.06, ALE 0.07, PME 0.08, PLE 0.05, AME-AME 0.12, AME-ALE 0.08, PME-PME 0.20, PME-PLE 0.12. MOQ length 0.26, MOQ posterior width 0.24, MOQ anterior width 0.24; leg formula: 1243: leg I—femur 1.09/ patella 0.72/ tibia 0.80/ metatarsus 0.65/ tarsus 0.47/ total 3.73; II—1.03/ 0.60/ 0.71/ 0.62/ 0.52/ 3.48; III—0.59/ 0.37/ 0.45/ 0.34/ 0.31/ 2.06; IV—0.66/ 0.36/ 0.44/ 0.37/ 0.30/ 2.13; total length 3.28, prosoma length 1.50, width 1.39, opisthosoma length 1.78, clypeus height 0.28, sternum length 0.66, width 0.60, endites length 0.30, width 0.16, labium length 0.18, width 0.30.

Variation. Besides sexual dimorphism in the coloration of the opisthosoma ( Fig. 3 ), the females (e.g. MCTP 6100) might have a darker prosoma and opisthosoma, and no yellow spots on legs. The median projection of the opisthosoma may be longer and acute ( Fig. 2 ).

Distribution. Brazil (Rio Grande do Sul to Amazonas) and Puerto Rico ( Mora ) ( Fig. 23 ).

Figures

FIGURES 1 – 4. Tobias caudatus Mello – Leitão, 1929. 1 – 3 habitus dorsal; 4 anterior view of the prosoma and ventral region of the left femur I and II (1 and 4 female MCTP 7593, 2 female MCTP 6100, 3 male MCTP 240). Scales: 1 mm. White arrow indicates the reddish – brown setiferous tubercles.

FIGURES 5 – 11. Tobias caudatus Mello – Leitão, 1929. 5 apex of the left chelicera, anterior and posterior row of teeth and fang; 6 detail of the sensorial pit on tibia I; 7 detail of the tarsus tip and retrolateral claw; 8 epigynum ventral view; 9 epigynum dorsal view; 10 palp ventral view; 11 palp retrolateral view (5 – 7 female MCTP 813, 8 – 9 female MCTP 5120, 10 – 11 male MCTP 1024). Scales: 0.25 mm. White arrow indicates the duster-shaped setae. cy—cymbium, DTA—dorsal tibial apophysis, e—embolus, RTA—retrolateral tibial apophysis, t—tegulum, ms—median septum, co—copulatory openings, mf—median field, lf—lateral fold, 1 s—primary spermatecae, 2 s—secondary spermatecae, cd—copulatory duct, fd—fertilization duct.

FIGURES 18 – 24. Tobias pustulosus Mello – Leitão, 1929. 18 detail of the sensorial pit on tibia I; 19 detail of the horn-like ocular mounds above the ALE; 20 epigynum ventral view; 21 epigynum dorsal view; 22 palp ventral view; 23 palp retrolateral view; 24 details of the canoe – shaped RTA joined with DTA (18, 20 and 21 female MCN 10690, 19 and 22 – 24 male MCZ). Scales: 0.25 mm. White arrow indicates the duster-shaped setae and the ocular mounds; black arrow indicates the teeth at DTA.