Macrobrachium

Valencia, Diego M. & Campos, Martha R., 2007, Freshwater prawns of the genus Macrobrachium Bate, 1868 (Crustacea: Decapoda: Palaemonidae) of Colombia, Zootaxa 1456, pp. 1-44 : 3-4

publication ID	https://doi.org/ 10.5281/zenodo.176325
DOI	https://doi.org/10.5281/zenodo.6237517
persistent identifier	https://treatment.plazi.org/id/FA4C87F6-3C4E-0B1C-FF52-AF39FA04FA06
treatment provided by	Plazi
scientific name	Macrobrachium
status

Treatment

Key to species of Macrobrachium View in CoL from Colombia

1. Second pair of pereopods different in shape ( Fig. 7 View FIGURE 7 C, D)...........................................................................2

— Second pair of pereopods similar in shape ( Fig. 6 View FIGURE 6 C, D)..............................................................................6

2. Larger second pereopod with carpus shorter than merus ( Fig. 7 View FIGURE 7 C)............................................................3

— Larger second pereopod with carpus as long as or longer than merus ( Fig. 9 View FIGURE 9 C).........................................4

3. External surface of palm of large chela of second pair of pereopods with rectangular space densely pubes- cent ( Fig. 11 View FIGURE 11 C) ........................................................................................................................... M. hancocki View in CoL

— External surface of palm of large chela of second pair of pereopods without densely pubescent rectangular space ( Fig. 7 View FIGURE 7 C) ....................................................................................................................... M. crenulatum View in CoL

4. Ventral margin row of palm of larger second pereopod with smaller spines on the base of finger ( Fig. 8 View FIGURE 8 C)......................................................................................................................................................................5

— Ventral margin row of palm of larger second pereopod with smaller spines on midpalm length ( Fig. 9 View FIGURE 9 C).. .................................................................................................................................................. M. faustinum View in CoL

5. Palm of larger second pereopod swollen with ventral margin strongly convex with external and internal surfaces of palm thickly pubescent ( Fig. 14 View FIGURE 14 C) ............................................................................ M. olfersii View in CoL

— Palm of larger second pereopod compressed with ventral margin straight or nearly convex with external and internal surfaces of palm less pubescent ( Fig. 8 View FIGURE 8 C) ................................................................ M. digueti View in CoL

6. Second pair of pereopods with merus longer than palm ( Fig. 2 View FIGURE 2 C)..............................................................7

— Second pair of pereopods with merus shorter than palm ( Fig. 3 View FIGURE 3 C)...........................................................10

7. Rostrum as long as or longer than scaphocerite ( Fig. 15 View FIGURE 15 A, 2 A).................................................................8

— Rostrum shorter than scaphocerite ( Fig. 16 View FIGURE 16 A) ............................................................................. M. praecox View in CoL

8. Merus shorter than carpus ( Fig. 2 View FIGURE 2 C)........................................................................................................... 9

— Merus same length as carpus ( Fig. 18 View FIGURE 18 C)........................................................................................ M. reyesi View in CoL

9. Upper margin of rostrum convex on orbital region ( Fig. 2 View FIGURE 2 A) ............................................. M. amazonicum View in CoL

— Upper margin of rostrum straight on orbital region ( Fig. 15 View FIGURE 15 A) ............................................ M. panamense View in CoL

10. Second pair of pereopods with carpus shorter than merus ( Fig. 3 View FIGURE 3 C).........................................................11

— Second pair of pereopods with carpus longer than merus ( Fig. 1 View FIGURE 1 C)..........................................................12

11. Fingers of second pair of pereopods longer than palm ( Fig. 5 View FIGURE 5 C). .............................................. M. carcinus View in CoL

— Fingers of second pair of pereopods as long as or shorter than palm ( Fig. 3 View FIGURE 3 C) .................. M. americanum View in CoL

12. Fingers of second pair of pereopods thickly pubescent ( Fig. 1 View FIGURE 1 C)..............................................................13

— Fingers of second pair of pereopods slightly pubescent or without pubescence ( Fig. 4 View FIGURE 4 C)......................15

13. Fingers of second pair of pereopods less than half of palm length ( Fig. 17 View FIGURE 17 C) ........................ M. rathbunae View in CoL

— Fingers of second pair of pereopods more than half of palm length ( Fig. 1 View FIGURE 1 C)..........................................14

14. Carpus of second pair of pereopods less than 10 times as long as wide ( Fig. 1 View FIGURE 1 C)................ M. acanthurus View in CoL

— Carpus of second pair of pereopods more than 10 times as long as wide ( Fig. 20 View FIGURE 20 B)................ M. tenellum View in CoL

15. Cutting edge of fingers of second pair of pereopods with row of small teeth of similar size from base to midportion or beyond ( Fig. 12 View FIGURE 12 C)...............................................................................................................16

— Cutting edge of fingers of second pair of pereopods without row of teeth of similar size ( Fig. 4 View FIGURE 4 C).......17

16. Palm of second pair of pereopods less than 4.5 times as long as wide ( Fig. 21 View FIGURE 21 C)............ M. transandicum View in CoL

— Palm of second pair of pereopods more than 4.5 times as long as wide ( Fig. 12 View FIGURE 12 C) ............ M. heterochirus View in CoL

17. Palm of second pair of pereopods more than 9 times as long as wide ( Fig. 10 View FIGURE 10 C) ...................... M. ferreirai View in CoL

— Palm of second pair of pereopods less than 7 times as long as wide ( Fig. 4 View FIGURE 4 C) …....................................18

18. Carapace without spinules on anterolateral surface ( Fig. 6 View FIGURE 6 A) ...................................................... M. cortezi View in CoL

— Carapace with spinules on anterolateral surface ( Fig. 4 View FIGURE 4 A)........................................................................19

19. Palm of second pair of pereopods strongly swollen, less than 3 times as long as high and with spines of different size on internal margin ( Fig. 13 View FIGURE 13 C, D) ......................................................................... M. nattereri View in CoL

— Palm of second pair of pereopods subcylindrical, more than 3 times as long as high and with spines of similar size on internal margin ( Fig. 4 View FIGURE 4 C, D) ............................................................................ M brasiliense View in CoL