Lacronia tenuis Carvalho & Kury 2023, comb. nov.
Creators: name: Carvalho, Rafael N.
name: Kury, Adriano B.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Opiliones
Gonyleptidae
Lacronia
Lacronia tenuis

description: Lacronia tenuis (Roewer, 1917) comb. nov.
Figs 3E–H, 4G, 19–20; Table 8
Discocyrtus tenuis Roewer, 1917: 116, fig. 19
Discocyrtanus nigrolineatus Mello-Leitão, 1935b: 381, fig. 11. Syn. nov.
Discocyrtus infelix Mello-Leitão, 1940: 7, fig. 9. Syn. nov.
Discocyrtus textor Piza, 1943: 53, fig. 8. [Junior subjective synonym of Discocyrtus infelix Mello- Leitão, 1940 by B. Soares (1944d: 172)].
Discocyrtus tenuis – Roewer 1923: 440, fig. 553; 1929: 207. — Mello-Leitão 1932: 177, fig. 97. — B. Soares 1945: 374. — Soares & Soares 1954: 255. — Acosta 1996: 216. — Kury 2003a: 166.
Discocyrtanus nigrolineatus – Mello-Leitão 1935a: 102.
Discocyrtus nigrolineatus – B. Soares 1945: 374; 1946: 518. — Soares & Soares 1954: 253. — Kury 2003a: 164.
Discocyrtus infelix – B. Soares 1944c: 172; 1945: 373; 1946: 516. — Soares & Soares 1954: 250.
Diagnosis
Lacronia tenuis comb. nov. can be differentiated from the other species of the genus by the following combination of characters: 1) mesotergum areas I–IV with areolate spots around the ordinary tubercles (Figs 3E–H, 4G, 19A); 2) mesotergum area I with two pairs of conspicuous tubercles (Figs 4G, 19A); 3) mesotergum area II with a transversal central row of prominent tubercles on all of its width (Figs 4G, 19A); 4) Ti III proventral face with a comb of four spines (iiII) on the distal third (Fig. 19E); 5) Ti III retro-ventral face with a pair of spines (iI) on the distal third (Fig. 19E); 6) Tr IV with a transversal prodorsal distal apophysis covered by a row of four prominent tubercles (Fig. 19A, F–G); 7) Fe IV with a dorsal row of spines (Fig. 19F–G, I); 8) Mt IV dorsal face with a row of subconical spines decreasing in size distally, becoming rounded tubercles (Fig. 19J).
Type material
BRAZIL – 1 ♂, holotype of Discocyrtus infelix Mello-Leitão, 1940; State of Rio de Janeiro, Mangaratiba; MNRJ 181ꜝ (examined) • 1 ♀ (wrongly assigned as ♂ in the original description), holotype of Discocyrtanus nigrolineatus Mello-Leitão, 1935; State of Rio de Janeiro, Angra dos Reis, Jussaral; MNRJ 42428ꜝ (examined) • 1 ♀, holotype of Discocyrtus tenuis Roewer, 1917; State of São Paulo, Santos; SMF RI 1316 (examined by photographs) • 1 ♂, 1 ♀, syntypes of Discocyrtus textor Piza, 1943; State of São Paulo, Serra da Bocaina, Fazenda Águas de Santa Rosa; MZSP 810 (examined).
Additional material examined
BRAZIL – State of Rio de Janeiro • 1 ♂, 2 ♀♀; Angra dos Reis, Estrada Lídice-Angra; 22.865° S, 44.247° W; 500 m a.s.l.; 1 Feb. 1997; A.B. Kury, R. Pinto-da-Rocha and L. Mestre leg.; MNRJ 5533 ꜝ • 1 ♂; RPPN Fazenda do Tanguá; Aug. 2009; C.A.S. Souza leg.; MZSP 36480 • 2 ♂♂; Itaguaí: 1948; Mattos and Maciel leg.; MNRJ 0037ꜝ • 1 ♂; Mangaratiba, Matutu, Caquizal da Márcia Khede; 22.87491° S, 43.99133° W; 500 m a.sl.; A.F. García, A.B. Kury and D.R. Pedroso leg.; MNRJ 260 • 3 ♂♂, 6 ♀♀; Reserva Ecológica do Rio das Pedras; 11–12 Nov. 2004; A.P.L. Giupponi leg.; MNRJ 17678ꜝ • 2 ♂♂, 1 ♀, 1 juv.; Parati, Trilha da Praia do Sono; Nov. 2005; M.B. da Silva and H.Y. Yamaguti leg.; MZSP 30100ꜝ • 2 ♂♂; Rio Claro; MNRJ 5545ꜝ • 1 ♂; Estação Repetidora da TV Globo; 22.865° S, 44.244° W; 800 m a.s.l.; 1 Mar. 1997; A.B. Kury, R. Pinto-da-Rocha and L. Mestre leg.; MNRJ 9275ꜝ • 2 ♂♂, 1 ♀; Rio de Janeiro, Restinga da Marambaia; 21 Oct. 1990; R.N. Costa leg.; MNRJ 6669ꜝ • 3 ♀♀; Teresópolis, Parque Nacional da Serra dos Órgãos; Aug. 2001; Equipe Biota leg.; IBSP 1935ꜝ. – State of São Paulo • 2 ♂♂; Ubatuba, Fazenda Capricórnio; 23 Feb. 1996; G. Machado leg.; MNRJ 5688ꜝ • 1 ♂; Picinguaba, Morro do Cuscuzeiro; 19–20 Jul. 1995; G.Machado; MNRJ 5689ꜝ • 1 ♀; same collection data as for preceding; MNRJ 5690ꜝ • 1 ♂; same collection data as for preceding; MNRJ 5691ꜝ.
Redescription
Male
MNRJ 260 for the external body illustrations and description; MNRJ 5533ꜝ for genitalic illustrations.
MEASUREMENTS. DS: CW 3.1, CL 2.2, AW 6.1, AL 3.6; legs I–IV measurements in the Table 8; right / left tarsal (distitarsal) counts: 6(3) / 6(3) - 12(3) / 11(3) - 7 / 7 - 7 / 7.
DORSUM. DS gamma-pyriform, as long as wide, with lateral borders of the AS convex, widest and thickest at mesotergum area III, with a sub-straight posterior border (Fig. 19A, E). DS anterior border with a set of six acuminated tubercles on each side, divided by a small central projection and a pair of shallow cheliceral sockets (Fig. 19A). Carapace with a paramedian pair of prominent tubercles, surrounded by ordinary tubercles on lateral and posterior portions (those on the central portion covered and surrounded by lighter spots compared to the background) (Figs 3E–H, 4G, 19A). Ocularium elliptical (in dorsal view), high (ca 4× the eye diameter), slightly inclined frontwards, placed in the anterior portion of the carapace (Fig. 19A–B, D). Ocularium with a pair of divergent spines (ca 3.5× the eye diameter), slightly inclined frontwards (Fig. 19A–B, D). Mesotergum divided into four clearly defined areas (Figs 3E– H, 4G, 19A). Mesotergum areas I and IV divided into left and right halves by a longitudinal median groove (Figs 3E–H, 4G, 19A). AS lateral borders with a row of three prominent tubercles (Figs 4G, 19A). AS lateral borders with two rows of ordinary tubercles from the anterior corner of the carapace to the posterior border (Fig. 19A). All areas tuberculate, with all tubercles individually covered and surrounded by lighter spots (compared with their background) (Figs 4G, 19A). Mesotergum area I with two pairs of prominent tubercles (Figs 4G, 19A). Mesotergum area II with a transversal central row of prominent tubercles occupying all the width (Figs 4G, 19A). Mesotergum area III with a pair of paramedian outstanding spines (ca 2× the ocularium spines) (Figs 4G, 19A, C–D). Mesotergum area IV with four to five prominent tubercles in a row surrounded by ordinary tubercles (Figs 4G, 19A). DS posterior border with a transversal row of prominent tubercles increasing in size to the center (Figs 4G, 19A). Free tergites I–III with a transversal row of prominent tubercles (Fig. 19A). Anal operculum tuberculate.
VENTER. Cx I–III sub-parallel to each other, each with ventral longitudinal rows of setiferous tubercles (Cx I rows with higher and sharper tubercles than the others). Cx II–III with a retro-ventral distal transversal row of acuminate tubercles. Cx IV much larger than the others, directed obliquely. Intercoxal bridges well-marked. Stigmatic area Y-inverted-shaped, clearly sunken in relation to Cx IV distal part.
Cx IV covered by ordinary tubercles. Cx IV posterior border and stigmatic area each with a transversal row of ordinary tubercles. Stigmata visible. Free sternites with a transverse row of ordinary tubercles.
CHELICERAE. Basichelicerite elongate, bulla well-marked, with marginal setiferous tubercles – two ectal, one posterior (Fig. 19A); hand not swollen.
PEDIPALPS. Tr with two geminate ventral setiferous tubercles. Fe with a ventral basal and a mesal apical setiferous tubercle. Pa unarmed. Ti with two rows (ventro-mesal and ventro-ectal) of four spines (IiIi). Ta with two rows of spines: three (iII) ventro-mesal and four (iIII) ventro-ectal.
LEGS. All the unmentioned podomeres are unarmed or without relevant armature. Tr I–III each with several ventral tubercles. Fe I sub-straight (Fig. 3E); Fe II straight (Fig. 3E); Fe III sinuous (Figs 3E, 19E). Fe and Ti I–III with all faces covered by longitudinal rows of small tubercles (Fig. 19E). Fe II–III with an apical retro-dorsal spur (Fig. 3A–B). Fe III with an apical prodorsal spur (reduced when compared to the retro-dorsal spur). Fe III and Ti III with two rows (proventral and retro-ventral) of small acuminate tubercles, distally presenting spines (outstanding spines on Ti III) (Fig. 19E). Pa I– III covered dorsally by tubercles. Ti III mace-shaped (Fig. 19E); Cx IV reaching the posterior border of DS (Fig. 19A). Cx IV tuberculate between prodorsal and ventral faces (Fig. 19A). Cx IV with a prolateral distal thick cylindrical apophysis (distally curved backwards, bearing a spine on the apex), posteriorly crenated (Fig. 19A, F–H). Cx IV with a retro-lateral distal spiniform apophysis, fused with a small secondary branch (Fig. 19A, H–I). Tr IV square-shaped (in dorsal view) (Fig. 19A, F, H). Tr IV with a dorsal central prominent subconical tubercle (Fig. 19A, F). Tr IV with a prolateral proximal sub-conical apophysis (Fig. 19A, F–H). Tr IV prodorsal distal face with transversal apophysis covered by four prominent tubercles (Fig. 19A, F–G). Tr IV ventral face tuberculate (Figs 19G–I). Tr IV retrolateral face with a proximal conical apophysis (slightly curved dorsad on the distal portion) (Fig. 19A, F, H–I). Tr IV retro-lateral face with a short distal spiniform apophysis (Fig. 19F, H–I). Fe IV straight (in dorsal view) and swollen at distal third (Fig. 19F–I). Fe IV with a dorsal row of eight conical spines (only the distalmost not curved to retro-lateral) (Fig. 19F–G, I). Fe IV prodorsal face with a row of nine prominent subconical tubercles (Fig. 19F–G). Fe IV prolateral face with a row of 1012 sub-conical tubercles (Fig. 19F–H). Fe IV proventral face with a row of sub-conical tubercles on proximal half and prominent conical tubercles on distal half (Fig. 19G–H). Fe IV with a central ventral row of sub-conical tubercles on the proximal third (Fig. 19G–I). Fe IV retro-ventral face with a row of subconical tubercles on basal two thirds and three conical spines on distal third (Fig. 19H–I). Fe IV with a retro-lateral row of seven spines, the three distalmost largest (Fig. 19F, H–I). Fe IV with a sizeable spur on prodorsal and retro-dorsal apical faces (Fig. 19F–I). Fe IV proventral and retro-dorsal faces with an outstanding spine on distal portion (Fig. 19G–I). Pa IV dorsally covered by sub-conical or acuminated prominent tubercles (Fig. 19F–G, I). Pa IV with a proventral row of four spines (III) (Fig. 19G–H). Pa IV with retro-ventral three spines (iII) (Fig. 19H–I). Ti IV (in dorsal view) irregularly covered by conical tubercles, with nine or ten outstanding conical spines: three on dorsal face central third; three or four on prodorsal basal ⅔ thirds; and two basalmost and one distalmost on retro-dorsal face) (Fig. 19F–G, I). Ti IV with a prolateral and retro-lateral row of sub-conical tubercles (Fig. 19F–I). Ti IV with a proventral row of sub-conical tubercles and two outstanding spines on distal portion (Fig. 19G–H). Ti IV retro-ventral with a row of spines (four outstanding spines on the distal half, the two distalmost largest (Fig. 19H–I). Mt IV dorsal face with a row of subconical spines decreasing in size distally, becoming rounded tubercles (Fig. 19J). COLOR (in vivo) (Fig. 3E–H). Ocularium background (including its pair of spines) Strong Brown (55). Carapace background, DS anterior portion and external portions of DS areas III Dark Yellowish Brown (78), with areolate spots Strong Greenish Yellow (99). AS lateral and posterior borders and free tergites I–III Dark Olive Brown (96). Mesotergum background and spines on the DS area III Brownish Black (65) with areolate spots Strong Greenish Yellow (99). AS lateral borders and the apex of the spines on the DS area III Strong Yellowish Brown (74). Tubercles on the DS, free tergites I–III and Cx IV dorsal face Greenish White (153). Ch and Pp background Moderate Olive Green (125), with honeycombed Olive Black (114) reticle. Tr I–III background in a mix of Dark Orange Yellow (72) and Dark Yellowish Brown (78). Fe–Mt I–III background Deep Greenish Yellow (100), with honeycombed Dark Grayish Olive Green (128) reticle. Tr III apophyses and Fe II–III retro-dorsal spurs Vivid Orange Yellow (66). Cx–Tr IV background Dark Reddish Brown (44) with Strong Reddish Brown ’s apophyses (40). FeMt IV background Dark Grayish Brown (62), with its distal tubercles and spines Deep Orange Yellow (69).
MALE GENITALIA. VP slightly divided into a distal half forming a rectangle with latero-apical flaps, and a proximal half elliptical (Fig. 20A, C). VP ventral surface entirely covered with microsetae of type 1 (Fig. 20B–C). All macrosetae inserted on the laterals of VP. MS A1–A3/A4 cylindrical, thick, and acuminate, forming a loose triangle in lateral view (A1 on the basal portion of the distal part, A2–A3/ A4 on the proximal part, A3 ventralmost) (Fig. 20A–C). MS B1 small, inserted ventrally close to A3 (Fig. 20B–C). MS C1–C3 similar in shape and size to MS A, forming a triangle in lateral view (C2 ventralmost) on the distal third of VP (Fig. 20A–C). MS D1 small, close to C3 (Fig. 20B). MS E1–E2 small, located on the distal flange of VP – E1 between MS C1–C2, E2 below C3 (Fig. 20C). Glans sac arising from the middle bulge on the podium, not extended as a dorsal process (Fig. 20A–B). Stylus and its ventral process axis fused basally, forming a prominent pedestal (Fig. 20A–B). Stylus cylindrical, almost straight (apex slightly bent ventrad), inserted on pedestal forming a 45º angle, without conspicuous head and with a few small subdistal tiny spines (Fig. 20A–B, D). Ventral process is half of the stylus length, slightly bent dorsad, with an apical flabellum (Fig. 20A, D). Flabellum curved ventrally, scallopshaped with serrulations, with approximately 35% of the ventral process stem length (Fig. 20A–D).
Female (MNRJ 5533ꜝ)
Remark: measurements and tarsal counts not assessed before its loss. DS gamma type. Cx IV narrower than in the males, with the prodorsal distal apophysis as a single outstanding spine and retro-ventral distal apophysis reduced to a tiny spine. Tr IV prolateral proximal portion unarmed. Tr IV retro-lateral face with a prominent proximal spine and distal one. Fe IV thinner than in the male, with five prominent spines on dorsal and retro-lateral faces. Mt IV dorsally covered by ordinary tubercles.
Intraspecific variation
In the minor morph males (compared to major morph): DS narrower; Cx IV with reduced prolateral and retro-lateral distal apophyses; Fe IV thinner, with reduced armature size. It was not found intraspecific variation among the major morph males or among females.
Historical taxonomic remarks
Discocyrtus tenuis (treated here as Lacronia tenuis comb. nov.) is known only from its female holotype (SMF RI 1316). Discocyrtus nigrolineatus was described based on the female holotype (MNRJ 42428ꜝ), which was incorrectly reported as a male by Mello-Leitão (1935b: 29). His mistake could have been caused by the well-developed armature of the specimen’s leg IV, a common pattern in males of Pachylinae. Both holotypes (Lacronia tenuis comb. nov. and D. nigrolineatus) have been studied for this project and they were considered to be morphologically identical, especially based on the unique diagnostic leg IV armature. The type localities of L. tenuis comb. nov. (Santos, São Paulo) and D. nigrolineatus (Angra dos Reis, Rio de Janeiro) are congruent within the geographic range of the other records of that morphotype. Therefore, D. nigrolineatus is herein considered a junior subjective synonym of L. tenuis comb. nov.
Discocyrtus infelix was described based on the male holotype (MNRJ 181ꜝ) with an illustration of its dorsal habitus (Mello-Leitão 1940: 9). It matches all major form males of L. tenuis comb. nov. studied here (we only used males coupled with females in the same vial previously identified as “ D. nigrolineatus ”). The type locality of D. infelix (Mangaratiba, Rio de Janeiro) is situated in the center of the geographic distribution of L. tenuis comb. nov. Hence, D. infelix is considered here a junior subjective synonym of L. tenuis comb. nov.
Records
BRAZIL, state of São Paulo: Juquiá (H. Soares 1966).
Geographic distribution (new records with an asterisk)
BRAZIL: state of Rio de Janeiro: Angra dos Reis, Itaguaí*, Mangaratiba, Parati*, Rio Claro*, Rio de Janeiro *, Teresópolis*. State of São Paulo: Santos, Ubatuba*.
description: Published as part of Carvalho, Rafael N. & Kury, Adriano B., 2023, Between areolated and band-shaped spots: a revision of Lacronia Strand, 1942 (Opiliones, Gonyleptidae), pp. 1-56 in European Journal of Taxonomy 859 on pages 46-51, DOI: 10.5852/ejt.2023.859.2043, http://zenodo.org/record/7641336