species, De Haan, 1849

Key for studied species View in CoL :

1.1 Pereiopods P1 and P2 carpus identically shaped. ...................................... ...2

1.2 Pereiopods P1 and P2 carpus differently shaped; P2 carpus is more elongated than that of P1. .........................................................................................3

2.1 Cephalothorax anterior border bearing a strong spine; straight rostrum rounded at its extremity with 2 to 6 small ventral teeth. ............................. Atyopsis spinipes

2.2 Cephalothorax anterior border acute bearing no spine; curved rostrum with 0 to 4 small ventral teeth. ............................................... Atyoida chacei sp. nov.

3.1 Eyes with cornea reduced to a small dark spot.. ... ... .. .... ... ... .. ..... Caridina rubella

3.2 Eyes with cornea normally developed.. ... ... .. .... ... ... .. .... ... ... ... .. .... ... ... ... ...4

4.1 Teeth absent on dorsalmarginof rostrum. ............................... Caridinatypus

4.2 More or less abundant teeth present on dorsal margin of rostrum.. ... .... .... ... ... ....5

5.1 Long stylocerite reaching or exceeding the first article of the antennal peduncle. .....6

5.2 Short stylocerite, failing toreach the firstarticle of the antennal peduncle.. ... .. .... ....8

6.1 Dorsal border of rostrum with 1–3 teeth located on the cephalothorax, posterior to the eye; P1 carpus 1.3–1.6 as long as wide.. ... ... .. .... ... ... .. .... ... ... ... .. .. C. lobocensis

6.2 Dorsal border of rostrum with 7–10 teeth located on the cephalothorax, posterior to the eye; P1 carpus 3.4–4.9 as longas wide. ....................................................7

7.1 Rostrum reaching to the base of the third segment of the antennular peduncle with 19–21 dorsalteeth ................................................ C. rintelenorum sp. nov.

7.2 Rostrum reaching beyond the end of the antennular peduncle with 21–26 dorsal teeth. .................................................................... C. cf. serratirostris

8.1 Short rostrum, curved downwards, 0.2–0.3 of cl, armed with 4–6 teeth on dorsal margin, 0 of them situated on carapace behind orbital margin. ........... C. ponapensis sp. nov.

8.2 Relatively long rostrum, 0.6–2.1 of cl, armed with 5–26 teeth on dorsal margin, 0–4 of them situated on carapace behind orbital margin. ......................................9

9.1 Uropodal diaeresis with 6–10 spiniform setae and a very long and upcurved rostrum with 5–9 dorsal teeth, widely spaced.. ................................... C. gracilirostris

9.2 Number of spiniform setae on uropodal diaeresis 8–15 and a long or short rostrum with 8–26 dorsalteeth, closelyset ........................................................10

10.1 Pre-anal carina with a prominent finger-like backward striking tooth. ........ C. appendiculata

10.2 Pre-analcarinaunarmed. ..................................................................11

11.1 P5 dactylus with a single terminal spine and a short distal propodus seta; posterior margin of the telson with intermediate setae longer or equal than lateral ones. ...................................................................... C. variabilirostris

11.2 P5 dactylus with two strong distal spines and a very long distal propodus seta; posterior margin of the telson with intermediate setae shorter or equal than lateral ones. ............................................................................. C. variabilis