Collettea

Key to species of the Collettea

1 Pleon shorter than pereonites 4­6 combined length..................................................... 2

­ Pleon longer than pereonites 4­6 combined length....................................................... 3

2 Pereonite 2 only 0.25 times longer than pereonite 1............................... Colettea sp. C

­ Pereonite 2 almost twice as long as pereonite 1....................................... C. humboldti

3 Uropods long (about as long as half of pleotelson)...................................................... 4

­ Uropods short (less than ¼ of pleotelson)................................................................... 6

4 Body short (7 times longer than wide) .......................................................... C. minima

­ Body long (11–15 times longer than wide)................................................................. 5

5 Pereonite 2–3 longer than wide, exopod uropod longer than half length of endopod proximal article............................................................................................. C. elongata

­ Pereonite 2–3 wider than long, exopod uropod shorter than endopod proximal article half length..................................................................................................... C. lilliputa

6 Pleon clearly shorter than pereonites combined length............................................... 7

­ Pleon at least as long as all pereonites combined length............................................ 15

7 Chela fixed finger with one seta................................................................................... 8

­ Chela fixed finger with two setae.............................................................................. 11

8 Pleotelson about as long as wide. Cheliped merus and carpus with 1–2 long seta(­ae) ventrally.................................................................................................... C. longipedia

­ Pleotelson clearly longer than wide. Cheliped merus and carpus without setae.......... 9

9 Carapace elongated twice as long as wide; antennule article 1 clearly longer than rest articles combined length................................................................................ C. subtilis

­ Carapace short, no longer than 1.5 of width; Antennule article 1 clearly shorter than rest articles combined length....................................................................................... 10

10 Pereonites 1–3 subequal. Carapace longer than pereonite 1­3 combined length................................................................................................................................... C. wilsoni

­ Pereonite 2 and 3 longer than pereonite 1. Carapace shorter than pereonite 1­3 com­ bined length........................................................................................... Collettea sp. B

11 Pleotelson as long as pleonites combined length .............................. C. rotundicaudata

­ Pleotelson shorter than pleonites combined length................................................... 12

12 Uropod endopod one articulated .................................................................. C. pegmata

­ Uropod endopod bi­articulated.................................................................................. 13

13 Cephalothorax short (shorther than 1.25 width) ........................................ C. cylindrata

­ Cephalothorax long (about 1.5 as long as width)....................................................... 14

14 Pereonite 4 and 5 as wide as long, pleon shorter than pereonites 2­5 combined length

.......................................................................................................................... C. alicjae ­ Pereonite 4 and 5 clearly wider than long, pleon as long as all pereonites combined length.......................................................................................................... C. antarctica 15 Pereonite 6 square or longer than wide...................................................................... 16

­ Pereonite 6 wider than long........................................................................................ 17

16 Pleotelson longer than pleonites 3–5 combined length......................... C. longipleona

­ Pleotelson shorter than pleonites 3–5 combined length........................ C. vermiformis

17 Pereonite 5 longer than wide..................................................................................... 18

­ Pereonite 5 wider than long............................................................... C. cylindratoides

18 Pereonite 6 subequal to 4th......................................................................................... 19

­ Pereonite 6 much shorter 4th.................................................................... C. larviformis

19 Cephalothorax short, about 1.25 times longer than wide, cheliped fixed finger with short and long seta ventrally........................................................................ C. arnaudi

­ Cephalothorax long, more than 1.5 times longer than wide, cheliped fixed finger with two long seta ventrally.......................................................................... Collettea sp. A