Aegla jaragua Moraes, Tavares & Bueno

Moraes, Juliana Cristina Bertacini, Terossi, Mariana, Buranelli, Raquel Corrêa, Mantelatto, Fernando L. & Bueno, Sérgio Luiz De Siqueira, 2016, Morphological and molecular data reveal the cryptic diversity among populations of Aegla paulensis (Decapoda, Anomura, Aeglidae), with descriptions of four new species and comments on dispersal routes and conservation status, Zootaxa 4193 (1), pp. 1-48 : 27-31

Aegla jaragua Moraes, Tavares & Bueno n. sp.

( Figs 1 , 20–21 , 24I–J , 25E , 27E , 28E , 29E , 30 )

Aegla paulensis .— Bond-Buckup & Buckup, 1994: 242 [pro parte] [not Aegla paulensis Schmitt, 1942 ].

Type material. Holotype: male [16.48 mm], Brazil, São Paulo, city of São Paulo, Jaraguá State Park, Pai Zé stream, 23°27’27.9”S –046°45’32.3”W, altitude 790 m, FPA Cohen, BF Takano and SLS. Bueno coll., 22.ii.2008 (MZUSP 34376). Paratypes: 5 males [largest male: 15.39 mm; smallest male: 11.13 mm] and 1 female [12.86 mm], ibidem, FPA Cohen, BF Takano and SLS. Bueno coll., 14.ix.2007 (MZUSP 34378). 7 males [not measured], ibidem, FPA Cohen, BF Takano and SLS. Bueno coll., 22.ii.2008 (MZUSP 34377).

Other material examined. 11 juvenile topotype specimens [not measured], ibidem, FPA Cohen, BF Takano and SLS. Bueno coll., 20.iii.2008 (MZUSP 34379, genetic voucher, Genbank access KU948371 ). MZUSP 18842 ( Jaraguá ). 1 male and 2 females [size not recorded], Brazil, São Paulo, Jaraguá State Park, collector and date not available (MZUSP 7317). 3 males, 1 female and 1 juvenile [size not recorded], ibidem, collector and date not available (MZUSP 7410).

Type-locality. Jaraguá State Park, city of São Paulo, São Paulo, Brazil.

Geographical distribution. species known only from the type-locality.

Diagnosis. Rostrum triangular, base wide, straight, extending beyond distal apex of compound eyes. Subrostral process in median position, well developed, high, broad triangular, slightly oriented anteriorly. Orbital spines well developed. Epibranchial area with corneous scales on anterolateral angle only. Areola subrectangular. Anteromesial region of third thoracic sternite truncate. Chelipeds large, palmar crests disciform with margin weakly lobulate. Uropods narrow. Posterolateral margin of telson slightly convex mesially.

Description of the male holotype. Carapace moderately convex, gastric region swollen, dorsal surface scabrous, covered with punctations with small setae. Rostrum triangular, base wide (value = 1.00), straight, extending beyond distal apex of compound eyes, with small setae on lateral margins and tip, with subterminal small corneous scales at tip ( Figs. 20 , 25E ). Rostral carina beginning at level of protogastric lobes, extending to near apex, with small corneous scales and setae ( Figs. 20 , 25E ). Subrostral process well developed, occupying median portion of subrostral margin, tip rounded, anterior and posterior margins forming obtuse angle (104°) ( Figs. 21 A, 27E).

Eyestalk and cornea well developed. Orbital sinus U-shaped, with plumose setae subventrally. Orbital spines well developed, rounded apically, with minute terminal corneous scale. Anterolateral spines rounded apically, with terminal small corneous scale, straight, not reaching basal margin of cornea ( Figs. 20 , 25E ).

Epigastric prominences pronounced with corneous scales. Protogastric lobes poorly pronounced with corneous scales. Gastric area moderately inflated in relation to hepatic lobes and rostrum in lateral view ( Figs. 20 , 25E ). Gastric pits small, smooth.

Demarcation between hepatic lobes well defined. Lateral margins of hepatic lobes with small setae and sparse corneous scales ( Figs. 20 , 25E ).

Transverse dorsal linea (TDL) slightly sinuous throughout its extension. Areola subrectangular (value = 1.85). Cardiac area trapezoidal (value = 1.69) ( Figs. 20 , 25E ).

Epibranchial area slightly elongated, triangular shaped, anterolateral angle blunt with two small corneous scales, margins and surface with scattered small simple setae ( Fig. 21 B).

Third thoracic sternite with anteromesial region truncate, with two terminal small corneous scales, and long simple setae scattered on the surface. Fourth thoracic sternite with anterolateral angles strongly produced ( Figs. 21 C, 29E).

Chelipeds unequal in size ( Fig. 20 ). Major cheliped. Dactylus: dorsal margin and outer surface granulate; inner surface smooth; proximal lobe on dorsal margin blunt and low; cutting margin with lobular basal tooth well developed proximally, with flattened corneous scales, followed by row of moderately wide corneous scales up to distal end; row of tufts of long simple setae next to cutting margin. Propodus: outer surface granulated; palm high (value = 3.16); palmar crest disciform, margin weakly lobulate, outer surface strongly excavated; cutting margin of fixed finger with lobular basal tooth well developed proximally, with flattened corneous scales, followed by row of moderately wide corneous scales up to distal end; scattered tufts of long simple setae over inner surface and alongside inner and outer surfaces next to cutting margin. Carpus: dorsal margin with two naked tubercles proximally, two spines with terminal corneous scale mesially, and sub-terminal lobe of moderate size, blunt, with small corneous scales; inner surface with group of five tubercles of unequal size (the largest one with small corneous scale), near dorsal margin and long setae; outer surface with carpal ridge high and formed by tubercles. Merus: dorsal margin with one tubercle; dorsolateral edge with five naked tubercles decreasing in size proximally; ventromesial edge with 1 spine with terminal corneous scale distally, three tubercles with terminal corneous scale medially, and one naked tubercle proximally; ventrolateral border with two naked tubercles distally. Ischium: dorsolateral edge with one naked spine distally; ventromesial border with four naked tubercles; ventrolateral border smooth.

Minor chelipeds similar to major chelipeds except as noted hereafter: Dactylus and fixed finger (propodus): cutting margin with lobular basal tooth weakly developed, followed by row of narrow corneous scales up to distal end. Carpus: inner surface with one large tubercle with small corneous scale and outer surface with carpal ridge moderately high and formed by tubercles. Merus: ventromesial edge with four tubercles with terminal corneous scale, except the proximalmost one; ventrolateral border with three naked tubercles distally. Ischium: ventromesial border with one tubercle with corneous scale distally, two low naked tubercles medially, and one tubercle with terminal corneous scale proximally.

Second, third and fourth pereiopods morphologically similar except where noted. Dactyli with several rows of setal tufts on all surfaces. Propodi with small corneous scales on dorsal margin and scattered setae concentrated mainly along dorsal and ventral margins. Carpi with scattered setae, concentrated mainly along dorsal margin; second and third pereiopods with small corneous scale on dorsal margin concentrated mainly on median and distal portions. Meri and ischii with scattered setae concentrated mainly along dorsal margin ( Fig. 20 ).

Fifth pereiopods reduced and chelate. Dactylus small, flattened, forming setose minute chela with propodus. Sexual tube long, narrow, opening on coxa ( Figs. 24I –J ).

Pleopods 2 and 5 absent, and 3 and 4 showing as buds.

Anterolateral angle of second abdominal epimeron and ventral angles of third and fourth abdominal epimera well defined, unarmed.

Uropods well developed, narrow ( Fig. 21 D).

Telson with anterolateral and posterolateral margins well-differentiated; posterolateral margin slightly convex mesially ( Fig. 21 D).

Variations. The base of the triangular rostrum is wider than the length of the sides, but in a few specimens the base is narrower than usual (RBW/LMR mean ratio = 1.03 ± 0.06; n = 11). The corneous scales on the cutting margins of the fingers of the major chela sometimes are distinctly less flattened than usual, and the palmar crest, usually disciform, may be rather rectangular in shaped in some specimens. The height of the palm of the propodus of the minor chela propodus is also variable (mean value = 4.26 ± 0.53; n = 07). The ventral angles of third and fourth abdominal epimera can be either naked or provided with corneous scales apically.

Remarks. Aegla jaragua n. sp. can be easily differentiated from all the congeners in the A. paulensis species complex in having the subrostral process in median position of the subrostral margin ( Fig. 27E ), whereas in all other members of the species complex the subrostral process is located on proximal half ( Figs. 27A–D, F ). The new species share with A. rosanae , A. lancinhas , A. vanini n. sp., and A. japi n. sp. the narrow-shaped type of the uropods ( Figs. 13 D, 15F, 17D, 19D, 21D); resembles A. vanini n. sp. and A. japi n. sp. in having the rostrum wide base triangular shaped and the telson with the posterolateral margin slightly convex mesially, and is further similar to A. vanini n. sp. and A. japi in the truncate shape of the anteromesial margin of the third thoracic sternite. These characters also enable the delimitation of A. jaragua n. sp. from A. paulensis s. str. (see under A. rosanae and A. vanini n. sp. for details). Aegla jaragua n. sp. can be further differentiated from A. paulensis s. str. and distinguished from A. rosanae in having the rostrum straight (the rostrum is distinctly curved downward in A. paulensis s. str., and curved upward distally in A. rosanae ) ( Figs. 11 A, 13A, 21A) and the margin of the palmar crest of both chelipeds weakly lobulate (the margin is lobulate in both A. paulensis s. str. and A. rosanae ) ( Figs. 10 , 12 , 20 ). The new species can be further differentiated from A. rosanae in (i) the subrectangular shape of the areola (the areola is rectangular in A. rosanae ) ( Figs. 12 , 20 , 25B, 25E ) and (ii) the truncate type of the anteromesial margin of the third thoracic sternite (it is abrupt in A. rosanae ) ( Figs. 29B, 29E ).

Aegla jaragua n. sp. differs from A. vanini n. sp. and A. japi n. sp. in having (i) straight rostrum (the rostrum is nearly deflected downward in both A. vanini n. sp. and A. japi n. sp.), (ii) well developed orbital spines (the orbital spines are absent in Aegla vanini n. sp., and rudimentary in A. japi n. sp.), and (iii) margin of palmar crest weakly lobulate (the margin of palmar crest is lobulate in A. vanini n. sp. and entire in A. japi n. sp.) ( Figs 16 , 18 , 20 ).

Aegla jaragua n. sp. further differs from A. lancinhas in (i) the blunt rostrum (rostrum lanceolate distally in A. lancinhas ), (ii) the absence of the corneous scales in the lateral margin of the epibranchial area (corneous scales present in in A. lancinhas ) ( Figs. 15 C, 28E), and (iii) the truncate type of the anteromesial margin of the third thoracic sternite (it is abrupt in A. lancinhas ) ( Figs. 15 D, 21C, 29E).

The material MZUSP 7317 and MZUSP 7410 from Jaraguá (São Paulo) assigned to A. paulensis by Bond- Buckup and Buckup (1994) is here reassigned to A. jaragua n. sp.

Biology. Several biological information regarding this species have recently been published as Aegla paulensis , and include data on the reproductive biology, population structure, somatic growth and life cycle ( Cohen et al. 2011), estimation of population size ( Cohen et al. 2013) and detailed morphological description of the newlyhatched juvenile (MZUSP 25140 and MZUSP 28283) ( Moraes & Bueno 2013).

Etymology. The specific epithet “ jaragua ”, from the indigenous Tupi-Guarani language “ jaraguá ” meaning “The Lord of the Valley” (“ yara ” = Lord + “ gua ” = The Valley) refers to the type-locality “ Jaraguá ”. It is a noun in apposition.

Figures

FIGURE 1. Distribution of the species of Aegla in four main hydrographic basins of southern Brazil: Rio Grande, Rio Tietê (Upper Paraná system), Rio Paraíba do Sul and Ribeira de Iguape. Indications L 1 through L 7 refer to the locations mentioned under “ sampling area ” in the Material & Methods section.

FIGURE 10. Dorsal view of Aegla paulensis Schmitt, 1942 s. str., male holotype (USNM 80023). Bar = 3.0 mm.

FIGURE 11. Aegla paulensis Schmitt, 1942 s. str., male holotype (USNM 80023). A, lateral view of the anterior region of the cephalothorax. B, dorsal view of epibranchial area. C, third and fourth thoracic sternites. D, telson, uropods and sixth abdominal segment. Note in A, the subrostral process (arrow). Bars: A = 2.0 mm. B = 0.50 mm. C = 1.0 mm. D = 3.0 mm.

FIGURE 12. Dorsal view of Aegla rosanae Campos Jr., 1998, male topotype (MZUSP 34369). Bar = 3.0 mm.

FIGURE 13. Aegla rosanae Campos Jr., 1998, male topotype (MZUSP 34369). A, lateral view of the anterior region of the cephalothorax. B, dorsal view of epibranchial area. C, third and fourth thoracic sternites. D, telson, uropods and sixth abdominal segment. Note in A, the subrostral process (arrow). Bars: A, D = 2.0 mm. B = 0.5 mm. C = 1.0 mm.

FIGURE 15. Aegla lancinhas Bond-Buckup & Buckup in Santos et al., 2015, male topotype (MZUSP 34403). A, lateral view of the anterior region of the cephalothorax. B, lateral view of subrostral process (arrow). C, epibranchial area with small corneous scale on the anterolateral angle and lateral margin (arrows). D, anteromesial region of third thoracic sternite abruptshaped. E, chelipeds subequal and poorly inflated. F, telson, uropods and sixth abdominal segment Bars: A = 1.0 mm; B, D = 0.5 mm; C = 0.2 mm; E, F = 2.0 mm.

FIGURE 16. Dorsal view of Aegla vanini n. sp., male holotype (MZUSP 34371). Bar = 3.0 mm.

FIGURE 18. Dorsal view of Aegla japi n. sp., male holotype (MZUSP 34374). Bar = 3.0 mm.

FIGURE 20. Dorsal view of Aegla jaragua n. sp., male holotype (MZUSP 34376). Bar = 3.0 mm.

FIGURE 21. Aegla jaragua n. sp., male holotype (MZUSP 34376). A, lateral view of the anterior region of the cephalothorax. B, dorsal view of epibranchial area. C, third and fourth thoracic sternites. D, telson, uropods and sixth abdominal segment. Note in A, the subrostral process (arrow). Bars: A, D = 2.0 mm; B = 0.5 mm; C = 1.0 mm.

FIGURE 30. Bayesian tree (TPM 2 uf + G) for Aegla species based on partial fragment of 16 S. Node numbers represent posterior probabilities (values <50 % are not shown), and divergence time in millions of years (my); * indicates the calibration points to molecular clock. The clade C proposed by Pérez-Losada et al. (2004) is highlighted in grey. The basin and sub-basin origin of the discussed species in this study are shown after the specific names.

FIGURE 24. A – L, proximal portion of fifth pereiopod showing coxa and sexual tube of long and narrow type. A – B, Aegla paulensis Schmitt, 1942 s. str., male topotype (MZUSP 34368). C – D, Aegla rosanae Campos Jr., 1998, male topotype (MZUSP 34369). E – F, Aegla vanini n. sp., male paratype (MZUSP 34372). G – H, Aegla japi n. sp., male paratype (MZUSP 34375). I – J, Aegla jaragua n. sp. male paratype (MZUSP 34378). K-L, Aegla jundiai n. sp., male paratype (MZUSP 13490). Bars: A – D, F – H, J = 200 µm; K, L = 100 µm; E, I = 500 µm.

FIGURE 25. A – F, dorsal view of cephalothorax and anterior portion of abdomen. A, Aegla paulensis Schmitt, 1942 s. str., male topotype (MZUSP 34367). B, Aegla rosanae Campos Jr., 1998, male topotype (MZUSP 34369). C, Aegla vanini n. sp., male holotype (MZUSP 34371). D, Aegla japi n. sp., male paratype (MZUSP 34375). E, Aegla jaragua n. sp., male paratype (MZUSP 34377). F, Aegla jundiai n. sp., female holotype (MZUSP 13493).

FIGURE 27. A – F, lateral view of subrostral process. A, Aegla paulensis Schmitt, 1942 s. str., male topotype (MZUSP 34367). B, Aegla rosanae Campos Jr., 1998, male topotype (MZUSP 34369). C, Aegla vanini n. sp., male holotype (MZUSP 34371). D, Aegla japi n. sp., male paratype (MZUSP 34375). Aegla jaragua n. sp., male paratype (MZUSP 34377). F, Aegla jundiai n. sp., female holotype (MZUSP 13493). Bars: A, D = 1.0 mm; B, C, E, F = 0.5 mm.

FIGURE 28. A – F, dorsal view of epibranchial area. A, Aegla paulensis Schmitt, 1942 s. str., male topotype (MZUSP 34367). B, Aegla rosanae Campos Jr., 1998, male topotype (MZUSP 34369). C, Aegla vanini n. sp., male holotype (MZUSP 34371). D, Aegla japi n. sp., male paratype (MZUSP 34375). E, Aegla jaragua n. sp., male paratype (MZUSP 34377). F, Aegla jundiai n. sp., female holotype (MZUSP 13493). Bars: 0.2 mm.

FIGURE 29. A – F, Ventral view of third (St 3) and fourth thoracic sternites. A, Aegla paulensis Schmitt, 1942 s. str., male topotype (MZUSP 34367). B, Aegla rosanae Campos Jr., 1998, male topotype (MZUSP 34369). C, Aegla vanini n. sp., male holotype (MZUSP 34371). D, Aegla japi n. sp., male paratype (MZUSP 34375). E, Aegla jaragua n. sp., male paratype (MZUSP 34377). F, Aegla jundiai n. sp., female holotype (MZUSP 13493). Note in A, St 3 tapered distally; St 3 abrupt in B; and St 3 truncate in C – F. Bars = 0.5 mm.