Figure 1
(A-H) Photomicrograph (SEM) of grooming leg, Megalobrachium pacificum Gore & Abele, 1974, female (MZUSP 33040). (A) Left P5, ventral view. (B) Simple setae on distomesial surface of coxa. (C) Pappose setae on distolateral surface of basis-ischium. (D) Pappose setae on lateral surface of merus. (E) Straight serrate setae on distal surface of carpus, ventral view. (F) Detail of the straight serrate setae on distal surface of carpus. (G) Sickle-shaped serrate setae on distoventral surface of dactylus. (H) Tooth-like cuspidate setae and club-shaped setae on distal margin of dactylus (chelae). Cx = coxa; BI = basis-ischium; M = merus; C = carpus; P = propodus; D = dactylus; CS = club-shaped setae; Pp = pappose setae; S0 = simple setae; S1 = sickle-shaped serrate setae; SS = straight serrate setae; TC = tooth-like cuspidate setae; TP = terminal pore. Scale bars = (A) 0.3 mm; (B, C, E-H) 0.01 mm; (D) 0.1 mm.
Figure 2
(A-H) Photomicrograph (SEM) of grooming leg, Megalobrachium roseum (Rathbun, 1900), female (MZUSP 33143). (A) Left P5, ventral view. (B) Pappose setae on distolateral surface of basis-ischium. (C) Straight serrate setae on distal surface of carpus, ventral view. (D) Detail of the straight serrate setae on distal surface of carpus. (E) Distal surface of chela (propodus and dactylus), frontal view. (F) Dactylus and distal third of propodus, lateral view. (G) Distal margin of propodus and dactylus with tooth-like cuspidate and club-shaped setae. (H) Detail of tooth-like cuspidate setae on distal margin of propodus and dactylus. Note in F distinct gap between fixed and movable fingers when chela is closed. Cx = coxa; BI = basis-ischium; M = merus; C = carpus; P = propodus; D = dactylus; CS = club-shaped setae; Pp = pappose setae; S0 = simple setae; S1 = sickle-shaped serrate setae; SS = straight serrate setae; TC = tooth-like cuspidate setae. Scale bars = (A) 0.1 mm; (B-D, G) 0.01 mm; (E, F) 0.05 mm; (H) 0.005 mm.
Figure 3
(A-H) Photomicrograph (SEM) of grooming leg, Pachycheles grossimanus (Guérin, 1835), male (MZUSP 26392). (A) Left P5, ventral view. (B) Straight serrate setae on distal surface of carpus, lateral view. (C) Detail of the straight serrate setae on distal surface of carpus. (D) Pappose setae (several setae with abraded setulae) on lateroproximal surface of coxa. (E) Simple setae on lateroproximal surface of basis-ischium (arrow indicates the suture line between the basis-ischium). (F) Distal surface of chela, frontal view. (G) Sickle-shaped serrate setae on distoventral surface of propodus. (H) Tooth-like cuspidate and club-shaped setae on distal margin of propodus. Cx = coxa; BI = basis-ischium; M = merus; C = carpus; P = propodus; D = dactylus; CS = club-shaped setae; Pp = pappose setae; S0 = simple setae; S1 = sickle-shaped serrate setae; SS = straight serrate setae; TC = tooth-like cuspidate setae. Scale bars = (A) 0.3 mm; (B, D-F) 0.1 mm; (C, G) 0.01 mm; (H) 0.005 mm.
Figure 4
(A, B) Photomicrograph (SEM) of grooming leg, Pachycheles grossimanus (Guérin, 1835), male (MZUSP 26392). (A) Distal margin of propodus and dactylus, frontal view showing tooth-like cuspidate and club-shaped setae. (B) Detail of tooth-like cuspidate and club-shaped setae on distal margin of propodus. (C-H) Photomicrograph (SEM) of grooming leg, Petrolisthes armatus (Gibbes, 1850), male (MZUSP 24562). (C) Left P5, ventral view. (D) Straight serrate setae on distal surface of carpus. (E) Detail of the straight serrate setae on distal surface of carpus. (F) Dactylus and propodus, lateral view. (G) Tooth-like cuspidate and club-shaped setae on distal margin of dactylus. (H) Detail of tooth-like cuspidate setae on distal margin of dactylus. Cx = coxa; BI = basis-ischium; M = merus; C = carpus; P = propodus; D = dactylus; CS = club-shaped setae; Pp = pappose setae; S0 = simple setae; S1 = sickle-shaped serrate setae; SS = straight serrate setae; TC = tooth-like cuspidate setae. Scale bars = (A, B, G) 0.01 mm; (C) 0.3 mm; (D, F) 0.1 mm; (E, H) 0.005 mm.
Figure 5
(A-F) Photomicrograph (SEM) of grooming leg, Petrolisthes tuberculatus (Guérin, 1835), male (MZUSP 25888). (A) Left P5, ventral view. (B) Distal surface of propodus and dactylus, lateral view. (C) Propodus and dactylus, lateral view. (D) Sickle-shaped serrate setae on distal surface of propodus. (E) Dactylus and distal third of propodus, lateral view. (F) Tooth-like cuspidate and club-shaped setae on distal margin of propodus. (G, H) Photomicrograph (SEM) of grooming leg, Pisidia longicornis (Linnaeus, 1767), male (MZUSP 18730). (G, H) Photomicrograph (SEM) of grooming leg, Pisidia longicornis (Linnaeus, 1767), male (MZUSP 18730). (G) Left P5, ventral view (arrow indicates the hinged articulation and the extensive area of arthrodial membrane between merus and carpus). (H) Tooth-like cuspidate setae on distal margin of dactylus. Note in B scattered club-shaped setae on the closing surface of dactylus, and in F tooth-like cuspidate setae furnished with a strong, single median spine. Cx = coxa; BI = basis-ischium; M = merus; C = carpus; P = propodus; D = dactylus; CS = club-shaped setae; Pp = pappose setae; S0 = simple setae; S1 = sickle-shaped serrate setae; SS = straight serrate setae; TC = tooth-like cuspidate setae. Scale bars = (A, G) 0.3 mm; (B, H) 0.005 mm; (C, E) 0.1 mm; (D, F) 0.01 mm.
Figure 6
(A-D) Photomicrograph (SEM) of grooming leg, Pisidia brasiliensis Haig in Rodrigues da Costa, 1968, male (MZUSP 23355). (A) Right P5, ventral view (arrow indicates the male gonopore). (B) Dactylus and distal third of propodus, lateral view. (C) Distal margin of propodus and dactylus with tooth-like cuspidate, club-shaped and simple setae. (D) Tooth-like cuspidate and club-shaped setae on distal margin of propodus. Note in D the inner and outer parts of tooth and terminal pore. (E-H) Photomicrograph (SEM) of the grooming leg, Polyonyx gibbesi Haig, 1956, male (MZUSP 19524). (E) Left P5, ventral view. (F) Distal surface of propodus and dactylus, frontal view. (G) Detail of distal surface of propodus and dactylus, frontal view. (H) Tooth-like cuspidate setae and club-shaped setae on distal margin of propodus. Note in H the tooth-like cuspidate setae provided with minute, unevenly sized, slightly acuminate teeth. Cx = coxa; BI = basis-ischium; M = merus; C = carpus; P = propodus; D = dactylus; CS = club-shaped setae; Pp = pappose setae; S0 = simple setae; S1 = sickle-shaped serrate setae; SS = straight serrate setae; TC = tooth-like cuspidate setae; TP = terminal pore. Scale bars = (A, F) 0.1 mm; (B, C, G) 0.01 mm; (D, H) 0.005 mm; (E) 0.3 mm.
Figure 7
(A-C) Photomicrograph (SEM) of grooming leg, Porcellana platycheles (Pennant, 1777), male (MZUSP 16261). (A) Left P5, lateral view. (B) Dactylus and distal half of propodus, lateral view. (C) Tooth-like cuspidate setae on distal margin of dactylus and propodus. (D-H) Photomicrograph (SEM) of grooming leg, Porcellana sayana (Leach, 1820), male (MZUSP 28138). (D) Left P5, ventral view. (E) Dactylus and distal third of propodus, lateral view. (F) Distal surface of propodus and dactylus, frontal view. (G) Distal margin of propodus and dactylus, frontal view, with tooth-like cuspidate, club-shaped and simple setae. (H) Detail of tooth-like cuspidate setae and club-shaped setae on distal margin of propodus. Note in E distinct gap between fixed and movable fingers when chela is closed, and in H the tooth-like cuspidate setae provided with minute, unevenly sized, slightly acuminate teeth. Cx = coxa; BI = basis-ischium; M = merus; C = carpus; P = propodus; D = dactylus; CS = club-shaped setae; Pp = pappose setae; S0 = simple setae; S1 = sickle-shaped serrate setae; SS = straight serrate setae; TC = tooth-like cuspidate setae. Scale bars = (A, D) 0.3 mm; (B, E, F) 0.1 mm; (C, G, H) 0.01 mm.
Figure 8
(A) Megalobrachium roseum (Rathbun, 1900). Schematic representation of the thoracic sternum in ventral view. (B, C) Petrolisthes armatus (Gibbes, 1850), male, dorsal view (MZUSP 18688). (B) Grooming leg (arrow) folded in Z-form in resting position outside the branchial chamber. (C) Grooming leg (arrow) kept inside the branchial chamber. Abbreviations: CxP1-P5, coxae of pereiopods 1 to 5; CxMxp3, coxae of maxiliped 3; ThSt III-VIII, thoracic sternites III to VIII; 3/4-6/7, thoracic sternal sutures; MA, membranous area. Scale bar: (A) = 1 mm. (B, C) = 5 mm.
Table 1
Porcelain crab species studied to date for grooming leg setation.
Table 2
Position of the articular condyles between the leg segments, from dactylus to coxa in pereiopods 2 to 5 (P2 to P5). Note in P5 that the articulation propodus-dactylus is rotated so that the articular condyles assume a dorsoventral position. D = dactylus; P = propodus; C = carpus; M = merus; Bi = basis-ischium; Cx = coxa; Pl-St = thoracic pleura-thoracic sternum; Ll = lateral to lateral; Dv = dorsoventral.
Table 3
Chaetotaxy and setal diversity among the studied porcelain species. Cx = coxa; BI = base-ischium; M = merus; C = carpus; P = propodus; D = dactylus; Ppt = tuft of pappose setae; Ppd = moderate dense fringe of pappose setae; Pps = scarce and minute pappose setae; S0 = simple setae; S1 = sickle-shaped serrate setae; SS = straight serrate setae; CS = club-shaped setae; TCt = tooth-like cuspidate setae straight truncate, with no distinct terminal projections; TCs = tooth-like cuspidate setae truncate, with a strong, broadly curved, sharp, single mesial spine; TCr = tooth-like cuspidate setae rounded, with minute, slightly acuminate teeth, but no strong spine.