Aegla franca, Schmitt, 1942

Francisco, Débora A., Bueno, Sérgio L. S. & Kihara, Terue C., 2007, Description of the first juvenile of Aegla franca Schmitt, 1942 (Crustacea, Decapoda, Aeglidae), Zootaxa 1509 (1), pp. 17-30 : 18-25

publication ID	https://doi.org/10.11646/zootaxa.1509.1.2
DOI	https://doi.org/10.5281/zenodo.15643318
persistent identifier	https://treatment.plazi.org/id/038C87B8-CD15-E940-FF03-F85DFBECFCDF
treatment provided by	Felipe
scientific name	Aegla franca
status

Treatment

Development in Aegla franca

is epimorphic. Upon hatching, the juveniles remain protected for a few days on the ventral side of the flexed abdomen of the female. When the female is disturbed, some juveniles may fall off as a consequence of the strong flapping movements of the female’s abdomen during the escape reaction. The benthic juveniles are then able to move around the bottom with the aid of the fully functional walking legs (second, third and fourth pairs of pereopods).

Carapace ( Fig. 1 View FIGURE 1 ). subcylindrical, slightly longer (mean: 1.71 mm; range: 1.58–1.79 mm) than wide (mean: 1.68 mm; range: 1.63–1.76 mm); rostrum long, triangular, well developed, and with a carina along its length; anterolateral spine well developed and reaching up to half the length of the eye peduncle; orbital spine small and defining a well developed orbital sinus and a much smaller extra-orbital sinus; hepatic lobes not discernible; protogastric lobes conspicuous; epigastric prominences absent; cervical groove well marked.

Antennule ( Figs. 2A View FIGURE 2 , 6A View FIGURE 6 ). Uniramous. Basal segment globose, distal half with 6 scattered, simple setae; 6 or 7 plumose setae and a semicircular fringe of 8 simple setae in between; proximal segment with 2 or 3 simple setae mesially; distal segment with 2–5 simple setae. Dorsal flagellum three-segmented; proximal segment lacking setae and aesthetascs; mesial segment with 1–3 simple setae and 1 aesthetasc distally; distal segment with 2 or 3 simple setae and 3 (occasionally 2) aesthetascs distally. Ventral flagellum one-segmented with 1 mesial, 1 apical and 3 or 4 subapical simple setae. Pores present; one near the distal border on the mesial segment of the dorsal flagellum and one subapical in the ventral flagellum ( Figs. 6A, C View FIGURE 6 ).

Antenna ( Figs. 2B View FIGURE 2 , 6B View FIGURE 6 ). Uniramous. Peduncle five-segmented. Coxa with 0–2 simple setae; base and ischium, representing the second and third segments, fused (ischiobasis), with 1–4 simple setae; merus subtriangular and bearing 2 or 3 distal simple setae; carpus with 2 or 3 simple setae mesially and 4 simple setae distally; flagellum long, multi-articulate, with 14–16 segments, proximal segment shortest and always without setae; all other remaining segments with 0–8 simple setae around the distal border, except the distal segment which presents simple setae in apical and subapical positions. Several segments of the flagellum present one pore near distal border, providing a somewhat regular distributional pattern along the flagellum ( Fig. 6B View FIGURE 6 ).

Mandible ( Fig. 2C View FIGURE 2 ). Uniramous. Incisor process rudimentary, asymmetrical and strongly calcified, with indented border bearing 2 blunt teeth; molar process rudimentary and resembling a small bump on the interior lower border; mandibular palp (endopod) two-segmented; proximal segment with up to 4 simple setae, 2 proximally and 0–2 distally; distal segment with 11–15 denticulate setae, distributed along margins of distal half region.

Maxillule ( Fig. 3A View FIGURE 3 ). Uniramous. Protopod with 2 or 3 plumose setae; coxal endite with 6 simple setae, 3– 5 pappose setae, 7 or 8 denticulate setae, all located along distal border; basal endite with 1 or 2 simple setae and 2 pappose setae subdistally, 5–7 denticulate setae distally and 9 cuspidate setae along distal margin; endopod long, indistinctly bilobed, with up to 3 denticulate setae, 1 mesially and 1 or 2 subdistally.

Maxilla ( Fig. 3B View FIGURE 3 ). Biramous. Coxal endite bilobed; lower lobe larger than the upper one, with 0 or 1 simple setae, 7 denticulate setae distally and 9 plumose setae subdistally; upper lobe with 2 simple setae proximally, 3 plumose setae mesially and 3 apical denticulate setae. Basal endite bilobed; lower lobe with 3 or 4 long setae bearing subterminal pore and several small scaly outgrowths subdistally on the pore facing surface ( Fig. 6D View FIGURE 6 ), 5 or 6 denticulate setae on the distal border, and 2 simple setae mesially. Upper lobe larger and more setose than the lower one, with 7 or 8 long setae bearing subterminal pore and small scaly outgrowths subdistally, identical to those described on the lower lobe, and 8–11 denticulate setae located on the distal border, and 1 simple setae mesially. Endopod elongated and devoided of setae. Exopod well developed, broad, with 5–8 simple setae on distal half of surface and a fringe of 70–77 plumose setae marginally.

First maxilliped ( Fig. 3C View FIGURE 3 ). Biramous. Coxal endite with 5 marginal denticulate setae, 1 denticulate setae on dorsal surface, and 4–6 pappose setae. Basal endite larger, subrectangular, with row of 5 plumodenticulate and 1 plumose setae on ventral surface, 2 simple setae on dorsal surface, 28 or 29 denticulate setae distributed along inner margin, and 1 or 2 pappose setae on outer margin. Endopod elongated, with 2 or 3 subapical and apical plumose setae. Exopod one-segmented, with 5 or 6 plumose setae along distal border.

Second maxilliped ( Fig. 4A View FIGURE 4 ). Biramous. Coxa with 7 or 8 pappose setae located on the inner margin. Endopod 5-segmented, ischiobasis (base and ischium fused) with 0–2 simple setae, 7–10 pappose setae, all located on the inner margin; merus subrectangular with 3–5 denticulate setae on the inner margin; carpus subtriangular with 2 denticulate setae, one of them is shorter and other much longer; propodus with 7–9 subdistal and distal denticulate setae, dactylus subtriangular with 10 denticulate setae on distal half region, and 2 apical serrate setae. Exopod two-segmented; proximal segment with 3–4 pappose setae near the inner border and 4– 5 marginal simple setae; distal segment (flagellum) bearing 1–2 simple setae and 3–4 apical plumose setae.

Third maxilliped ( Figs. 4B View FIGURE 4 , 6E–F View FIGURE 6 ). Biramous. Endopod five-segmented; ischiobasis with 6 or 7 simple setae and 8 denticulate setae along inner border of the base section; 6–8 simple setae and 5–7 denticulate setae evenly distributed, 1 conspicuous spiniform projection subdistally near outer margin ( Fig. 6F View FIGURE 6 ), crista dentata along inner margin formed by 9 or 10 corneous tubercles which become progressively larger towards distal border ( Figs. 4B View FIGURE 4 , 6F View FIGURE 6 ); merus subrectangular with 5–7 simple setae evenly distributed and 4 denticulate setae on the inner margin; carpus subcylindrical with 3–5 simple setae and 11–13 denticulate setae distributed over distal half region; propodus with 7 or 8 simple setae, 14 denticulate setae and 3 or 4 sword setae ( Fig. 6E View FIGURE 6 ); dactylus subcylindrical and rounded apex, with 1–4 simple setae, 10–13 denticulate setae and 4 or 5 serrate setae, all located on the distal half of the segment. Exopod two-segmented; proximal segment with 1 or 2 marginal simple setae; distal segment (flagellum) with 0 or 1 simple setae and 4 apical plumose setae.

Cheliped ( Figs. 4C View FIGURE 4 , 6G View FIGURE 6 ). Uniramous and six-segmented. Coxa with 14–19 simple setae; base and ischium fused (ischiobasis), subrectangular with 12–19 simple setae; merus subrectangular with 22–28 simple setae; carpus subtriangular with 20–25 simple setae; propodus with 30–44 and 46–52 simple setae on manus and fixed finger, respectively; cutting edge of fixed finger with 13 or 14 denticles obliquely and serially arranged and 1 apical robust spine ( Fig. 6G View FIGURE 6 ); dactylus with 1 apical robust spine; 43–54 simple setae and bearing 13–18 denticles obliquely and serially arranged on the cutting edge ( Fig. 6G View FIGURE 6 ). These denticles along the cutting edge of both fingers are less numerous and more spaced in the proximal half. In the distal half, the series of denticles are so closely together that they partially overlap one another.

Second pereopod ( Fig. 5A View FIGURE 5 ). Uniramous. Coxa with 15–18 simple setae; base and ischium fused (ischiobasis), subrectangular and with 17–26 simple setae; merus subrectangular, longer than the other segments of the appendage, with 27–42 simple setae; carpus subrectangular with 20–30 simple setae; propodus subrectangular with 37–44 simple setae; dactylus subtriangular with 50–67 simple setae and an apical robust spine.

Third and fourth pereopods uniramous and similar to second pereopod.

Fifth pereopod ( Figs. 5B View FIGURE 5 , 6H–I View FIGURE 6 ). Uniramous, reduced as compared to other pereopods, and not used for locomotion. Dacylus and fixed finger of propodus form a minute chela ( Fig. 6H View FIGURE 6 ). Protopod globose with 0–2 simple setae; ischium subrectangular with 1 or 2 simple setae; merus subrectangular with 2–3 simple setae; carpus subrectangular with 3 or 4 distal simple setae; propodus with 24–28 simple setae distributed over the distal half and 3 apical stout serrate setae ( Fig. 6I View FIGURE 6 ); dactylus with 5 simple setae and 4 serrate setae ( Fig. 6I View FIGURE 6 ).

Uropods ( Fig. 5C View FIGURE 5 ). Biramous. Basal segment (protopod) short, with 3 or 4 mesial simple setae and 2 or 3 marginal plumose setae. Endopod with 5–7 simple setae submarginally and 18 or 19 plumose setae along free border; exopod with, 2–4 simple setae submarginally and 22–25 marginal plumose setae along free border. On both endopod and exopod, the distalmost group of plumose setae are the longest.

Telson ( Fig. 5C View FIGURE 5 ). laminate, subtriangular, lacking dorsal longitudinal suture; 7–11 long plumose setae along posterior border and 20–26 simple setae distributed over the dorsal surface.