Aegla jundiai 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 : 31-40

Aegla jundiai Moraes, Tavares & Bueno n. sp.

( Figs 1 , 22–23 , 24K–L , 25F , 27F , 28F , 29F , 30 )

Aegla paulensis .— Pérez-Losada et al., 2004 pro parte: 780 [not Aegla paulensis Schmitt, 1942 ].

Type material. Holotype: female [11.37 mm] Brazil, São Paulo, Serra do Japi – Guaxinduva–Jaguacoara , 23°17’22.7”S –046°56’52.0”W, point 11, F Kiyohara and E Mossolin coll., 09.ii.2000 (MZUSP 13493). Paratypes: 1 male [11.92 mm], ibidem, 23°17’21.7”S–046°56’24.7”W, point 10, F Kiyohara and E Mossolin coll., 08.ii.2000 (MZUSP 13490). 1 male [11.86 mm] and 1 female [9.87 mm], ibidem, 23°17’33.8”S–046°57’13.9”W, point 12, F Kiyohara and E Mossolin coll., 08.ii.2000 (MZUSP 13497).

Type-locality. Serra do Japi –Guaxinduva–Jaguacoara, state of São Paulo, Brazil.

Geographical distribution. Known only from the type-locality.

Diagnosis. Rostrum triangular, base wide, nearly deflected downward, not reaching distal apex of compound eyes. Subrostral process on proximal half, well developed, high, broad triangular, and oriented downward. Orbital spines rudimentary. Corneous scales at epibranchial area inconspicuous on anterolateral angle only. Areola rectangular. Third thoracic sternite with anteromesial region truncate. Chelipeds small, palmar crests rectangular with margin jagged. Uropods narrow. Posterolateral margin of telson straight.

Description of the female holotype. Carapace moderately convex, gastric region swollen, dorsal surface scabrous, covered with punctations with small simple setae. Rostrum triangular, base wide (value = 1.09), nearly deflected downward, not reaching distal apex of compound eyes, with small corneous scales at tip, with small simple setae on lateral margins and surface ( Figs. 22 , 25F , 27F ). Rostral carina beginning at level of protogastric lobes, extending to near apex, with small simple setae. Subrostral process well developed, on proximal half of subrostral margin, tip rounded, anterior and posterior margins forming obtuse angle (103°) ( Fig. 23 A).

Eyestalk and cornea well developed. Orbital sinus U-shaped, with plumose setae subventrally. Orbital spines rudimentary, rounded apically, with terminal minute corneous scale. Anterolateral spines rounded apically with terminal small corneous scale, straight, not reaching basal margin of cornea ( Fig. 22 ).

Epigastric prominences and protogastric lobes pronounced, with minute simple setae, without corneous scales. Gastric area moderately inflated in relation to hepatic lobes and rostrum in lateral view. Gastric pits inconspicuous.

Demarcation between hepatic lobes well defined (right side only). Lateral margins of hepatic lobes with scattered small simple setae ( Fig. 22 ).

Transverse dorsal linea (TDL) slightly sinuous throughout its extension. Areola rectangular (value = 2.35). Cardiac area trapezoidal (value = 1.50) ( Figs. 22 , 25F ).

Epibranchial area shortened, anterolateral angle blunt with a minute corneous scale (left side only), margins and surface with scattered small simple setae ( Figs. 23 B, 28F).

Anteromesial region of third thoracic sternite truncate, with minute corneous scale on each anterolateral angle of anterior margin; scattered small simple setae on surface. Fourth thoracic sternite with anterolateral angles moderately produced with scattered long simple setae ( Figs. 23 C, 29F).

Chelipeds subequal in size ( Fig. 22 ). 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 narrow corneous scales up to distal end; row of tufts of long simple setae next to cutting margin. Propodus: outer surface granulate; palm high (value = 4.06); palmar crest rectangular, margin jagged, outer surface weakly excavated; cutting margin of fixed finger with lobular basal tooth well developed proximally, with flattened corneous scales, followed by row of narrow 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 low and naked tubercles proximally, two median spines with small terminal corneous scale apically, and sub-terminal lobe weakly defined, blunt, with a small corneous scales and setae apically; inner surface with one spine with terminal corneous scale, near dorsal margin and long setae; outer surface with carpal ridge moderately high and formed by tubercles. Merus: dorsal margin with one tubercle; dorsolateral edge with two larger tubercles distally and two low tubercles median-distally; ventromesial edge with three naked tubercles decreasing in size proximally; ventrolateral border with four small naked tubercles. Ischium: dorsolateral edge with one naked tubercle distally; ventromesial border with five naked tubercles (proximalmost and distalmost ones larger than three median); ventrolateral border smooth.

Minor chelipeds similar to major chelipeds except as noted hereafter: Dactylus: lobular basal tooth weakly developed. Propodus: palm low (value = 4.52) and lobular basal tooth weakly developed. Carpus: sub-terminal lobe on dorsal margin well defined with two corneous scales and setae, inner surface with two tubercles without corneous scales, and outer surface with carpal ridge high. Merus: dorsolateral edge with five tubercles tipped by corneous scale and decreasing in size proximally; ventromesial edge with one tubercle with terminal corneous scale distally and four low naked tubercles median-proximally; ventrolateral border with two naked tubercles distally.

Second and third pereiopods (right side only; left side missing). Dactylus with several rows of setal tufts on all surfaces. Propodus with scattered setae concentrated mainly along dorsal and ventral margins. Carpus with scattered setae concentrated mainly along dorsal margin, and with minute corneous scale on distal portion of dorsal margin. Merus and ischium with scattered setae concentrated mainly along dorsal margin. Pair of fourth pereiopods missing ( Fig. 22 ).

Fifth pereiopods reduced and chelate. Dactylus small, flattened, forming setose minute chela with propodus. Sexual tube absent on coxa.

Pleopods 2 to 5 well developed, uniramous and bi-segmented.

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

Uropods well developed, narrow ( Fig. 23 D).

Telson with anterolateral and posterolateral margins well-differentiated; posterolateral margin straight mesially ( Fig. 23 D).

Variations. The areola can be actually either subrectangular or rectangular, mean value = 2.26 ± 0.18 (n = 04), and the palm of the propodus of the minor chela varies in height (mean value = 4.34 ± 0.62; n = 03). In the male MZUSP 13497 the palmar crest of the minor chela is disciform instead of rectangular, and in the male MZUSP 13490 the sub-terminal lobe of the carpus of the major chela is well defined and pointed, whereas in the holotype it is weakly defined and blunt. The male paratypes are provided with long and narrow sexual tubes ( Figs. 24K–L ).

Remarks. Aegla jundiai n. sp. can be easily recognized by a unique combination of characters, which includes the palmar crest of both chelipeds with jagged margin ( Fig. 22 ), and the small size of the chelae (all other members of the species complex have larger chelae, except A. lancinhas ). The new species is similar to A. rosanae , A. lancinhas , A. vanini n. sp., A. japi n. sp., and A. jaragua n. sp. in having narrow uropods ( Figs. 13 D, 15F, 17D, 19D, 21D, 23D). It further resembles A. vanini n. sp., A. japi n. sp., and A. jaragua n. sp. in having the rostrum wide base triangular shaped, and in the truncate shape of the anteromesial margin of the third thoracic sternite ( Figs. 29C–F ); A. rosanae in the rectangular areola ( Figs. 12 , 22 ); A. vanini n. sp. and A. japi n. sp. in the rostrum deflected downward; and A. japi n. sp. in the rudimentary orbital spines ( Figs 25D, F ). All these characters allow distinguishing A. jundiai n. sp. (and the five other members of this species complex) from A. paulensis s. str.

Aegla jundiai n. sp. further differs from A. rosanae and A. lancinhas in having (i) the rostrum nearly deflected downward (the rostrum is curved upward distally in A. rosanae and nearly straight in A. lancinhas ); (ii) the orbital spines rudimentary (the orbital spines well developed in both A. rosanae and A. lancinhas ); (iii) the anteromesial margin of the third thoracic sternite truncate (the anteromesial margin of the third thoracic sternite is abrupt in both A. rosanae and A. lancinhas ) ( Figs. 15 D, 29B, 29F).

Aegla jundiai n. sp. can be separated from A. vanini n. sp., A. japi n. sp. and A. jaragua n. sp. in having the posterolateral margin of the telson straight (instead of slightly convex mesially) ( Figs. 17 D, 19D, 21D). It can be further differentiated from A. vanini n. sp. in that the rostrum does not reach distal apex of compound eyes (instead of extending beyond the compound eyes as in A. vanini n. sp.) and from both A. vanini n. sp. and A. jaragua n. sp. in that the orbital spines are rudimentary (instead of absent as in A. vanini n. sp. and well developed as in A. jaragua n. sp.) ( Figs. 16 , 20 , 22 ); from both A. japi n. sp. and A. jaragua n. sp. in the absence of corneous scales on the epigastric prominences and protogastric lobes (instead of having inconspicuous corneous scales as in A. japi n. sp. and A. jaragua n. sp.); from A. japi n. sp. in the areola rectangular in shape (instead of subrectangular as in A. japi n. sp.) ( Figs. 25D, 25F ); and from A. jaragua n. sp. in that the rostrum is deflected downward (instead of straight) and the areola is rectangular in shape (instead of subrectangular).

The female holotype is the only specimen in the type-series to have both chelipeds, although the major cheliped is detached from the body.

The specimens of A. jundiai examined in the present study belong to the same collection of Aegla paulensis s. lat. from which molecular sequences (Genbank access AY595838 ) are available ( Pérez-Losada et al. 2004).

Biology. Unknown.

Etymology. The specific epithet “ jundiai ”, from the indigenous Tupi-Guarani language “ jundiaí ” (“ jundiá ” = a species of catfish + “ í ” = river) means “the river of the jundiás”, refers Jundiaí City where the type-locality is located. 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 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 17. Aegla vanini n. sp., male holotype (MZUSP 34371). A, lateral view of the anterior region of the cephalothorax. B, dorsal view of the right 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 = 0.25 mm; C = 1.0 mm.

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

FIGURE 22. Dorsal view of Aegla jundiai n. sp., female holotype (MZUSP 13493). Bar = 2.0 mm.

FIGURE 23. Aegla jundiai n. sp., female holotype (MZUSP 13493). 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 = 0.25 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.