Grapsus tenuicrustatus, (HERBST, 1783)

Flores, Augusto A. V., Paula, José & Dray, Tiago, 2003, First zoeal stages of grapsoid crabs (Crustacea: Brachyura) from the East African coast, Zoological Journal of the Linnean Society 137 (3), pp. 355-383 : 360-365

GRAPSUS TENUICRUSTATUS (HERBST, 1783) (FIGS 3,4)

Dimensions: TT 0.92 mm ± 0.01, CW 0.50 mm ± 0.01, CL 0.38 mm ± 0.01.

Carapace ( Fig. 3a ): rostral spine straight.

Antenna ( Figs 3a,c ): as long as rostral spine; protopodal process with 2 rows of a few large spines of increasing size towards the tip.

Maxillule ( Fig. 4f ): coxal endite with 6 (sparsely plumose) setae.

Maxilla ( Fig. 4g ): basial endite bilobed with 5 (3 sparsely plumose, 2 plumodenticulate) setae + 4 (3 sparsely plumose, 1 plumodenticulate) setae; endopod bilobed with 2 (sparsely plumose) + 2 (sparsely plumose) setae.

First maxilliped ( Fig. 4h ): basis with 8 setae (arranged 1 sparsely plumose, 1 simple; 2 simple; 2 simple; 2 simple); endopod five-segmented with 1 (simple), 2 (simple), 1 (simple), 2 (plumodenticulate), 5 (1 subterminal simple + 4 terminal plumodenticulate) setae.

Second maxilliped ( Fig. 4i ): basis with 4 setae (arranged 1 sparsely plumose, 1 sparsely plumose, 1 simple, 1simple); endopod 3-segmented with 0, 1 (denticulate), 5 (1 subterminal denticulate + 2 terminal simple, 2 terminal sparsely plumose) setae.

Abdomen ( Figs 3a,d ): postero-lateral processes in all somites, small in somite 1, larger but still blunt in somite 2, and especially well-developed in somite 3.

Telson ( Figs 3d,e ): with 2 postero-lateral pairs of spines, the posterior one larger; forks small, divergent.

ILYOGRAPSUS PALUDICOLA (RATHBUN, 1909)

(FIGS 5,6)

Ilyograpsus paludicola ; Fukuda, 1978: 15.

Dimensions: CW 0.23 mm ± 0.01, CL 0.35 mm ±

0.01.

Carapace ( Fig. 5a ): with large lateral expansions, bearing a distinct spine on posterior edge; dorsal spine absent; rostral spine short; lateral spines absent; 1 pair of dorsal setae present; eyes sessile.

Antennule ( Fig. 5b ): uniramous, endopod absent; exopod unsegmented bearing 2 terminal aesthetascs and 1 terminal seta.

Antenna ( Figs 5a,c ): of similar size to rostral spine; protopodal process with 2 rows of spines of different size; endopod absent; exopod well developed, slightly longer than protopodal process, with spines aligned, smaller towards the tip.

Maxillule ( Fig. 6f ): epipod seta absent; coxal endite with 5 (2 sparsely plumose, 3 denticulate) setae; basial endite with 5 (1 subterminal, plumodenticulate, 4 stout, terminal denticulate) setae; endopod 2- segmented with 1 (simple) seta on proximal segment and 5 (1 simple, subterminal + 4 distal, plumodenticulate) setae in distal segment; exopod seta absent.

Maxilla ( Fig. 6g ): coxal endite bilobed bearing 4 (sparsely plumose) + 3 (sparsely plumose) setae, basial endite bilobed with 5 (2 sparsely plumose, 3 plumodenticulate) setae + 4 (1 sparsely plumose, 3 plumodenticulate) setae; endopod bilobed with 2 (1 longer plumodenticulate, 1 shorter sparsely plumose) setae + 2 (1 longer plumodenticulate, 1 shorter sparsely plumose) setae; scaphognathite (exopod) margin with 4 plumose setae and 1 long distal stout process.

First maxilliped ( Fig. 6h ): basis with 9 setae (arranged 2 sparsely plumose; 2 sparsely plumose; 2 sparsely plumose, 1 simple; 2 sparsely plumose); endopod 5-segmented with 2 (1 sparsely plumose, 1 simple), 2 (simple), 1 (simple), 2 (sparsely plumose), 5 (1 subterminal sparsely plumose + 2 terminal plumodenticulate, 2 terminal sparsely plumose) setae; exopod unsegmented with 4 terminal plumose natatory setae.

Second maxilliped ( Fig. 6i ): basis with 4 setae (arranged 1 sparsely plumose, 1 sparsely plumose, 1 simple, 1 sparsely plumose); endopod 3-segmented with 0, 1 (simple), 5 (1 terminal simple, 4 terminal sparsely plumose) setae; exopod unsegmented with 4 terminal plumose natatory setae.

Third maxilliped: absent

Pereiopods: absent

Abdomen ( Figs 5a, d ): 5 somites; somites 2–3 with a pair of lateral processes, posteriorly directed in somite 3; postero-lateral process only conspicuous in somite 1; a pair of median postero-dorsal setae in somites 2–5.

Telson ( Figs 5d,e ): small spinules distributed in scattered patches, lateral and dorsal medial spines absent; acute denticles bordering the proximal inner margin of forks and a row of small denticles aligned close to the outer margin; forks slightly divergent; posterior margin with 3 pairs of stout setae margined by spinulae of different size.

Figures

Figure 3. Grapsus tenuicrustatus (Herbst). First zoeal stage: (a) lateral view; (b) antennule; (c) antenna; (d) dorsal view of abdomen; (e) detail of telson. Scale bars as in Figure 1.

Figure 4. Grapsus tenuicrustatus (Herbst). First zoeal stage: (f) maxillule; (g) maxilla; (h) first maxilliped; (i) second maxilliped. Scale bars as in Figure 2.

Figure 5. Ilyograpsus paludicola (Rathbun). First zoeal stage: (a) lateral view; (b) antennule; (c) antenna; (d) dorsal view of abdomen; (e) detail of telson. Scale bars represent 0.1 (a), 0.05 (b, c and e) and 0.1 mm (d).

Figure 6. Ilyograpsus paludicola (Rathbun). First zoeal stage: (f) maxillule; (g) maxilla; (h) first maxilliped; (i) second maxilliped. Scale bars as in Figure 2.