Key:  Suborder Caprellidea

Phylum Arthropoda
 Subphylum Crustacea
  Class Malacostraca
   Subclass Eumalacostraca
    Superorder Peracarida
     Order Amphipoda
 

Taken primarily from  Kozloff, 1987, 1996 p.387  (Copyright 1987, 1996, University of Washington Press.  Used in this web page by permission of University of Washington Press)
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Lower taxonomic level Main Page Alphabetic Index Systematic Index Glossary
1a  With gills on pereonites 2-4; mandible without molar process 2
1b With gills on pereonites 3 and 4 only; mandible with a molar process 3
2a Perepods 3 and 4 with 1 article, pereopod 4 with 1 article; abdomen small and without obvious segmentation Cercops compactus
2b Pereopods 3 and 5 with 3 articles, pereopod 4 with 1 article; abdomen small and without obvious segmentation Petrotripus brevis
3a With vestigial pereopods on pereonites 3 and 4; mandible with a palp 4
3b Without pereopods on pereonites 3 and 4; mandible without a palp 7
4a Pereopods 3 and 4 consisting of 2 articles; antenna 2 without long setae 5
4b Pereopods 3 and 4 consisting of only 1 article; antenna 2 with long setae on the larger articles 6
5a Head with a median dorsal spine (in the male) or a knob (in the female); pereopod 5 consisting of 6 articles; gnathopod 2 of male attached to the anterior half of pereonite 2 Deutella californica
5b Head without a median dorsal spine or knob; pereopod 5 consisting of 3 articles; gnathopod 2 of male attached to the posterior half of pereonite 2 Mayerella banksia
6a Next-to-last article of antenna 2 about 4 times as long as wide, with setae not appreciably longer than its width; short spines on pereonites directed more nearly anteriorly than laterally Tritella laevis
6b Next-to-last article of antenna 2 about 6 times as long as wide, with some setae about twice as long as its width; short spines on pereonites directed more laterally than anteriorly Tritella pilimana
7a Width of propodus of gnathopod 2 about four-fifths the length of this article; length of adults about 4 mm; with a pair of grasping spines on the proximal half of the propodus of pereopods 5-7 (found on the surface of the sea star Henricia leviuscula, as well as on hydroids and other organisms) Caprella greenleyi
7b Width of propodus of gnathopod 2 less than two-thirds the length of this article; length of adults generally greater than 5 mm; with a single grasping spine or tooth on the propodus of pereopods 5-7 8
8a With a ventral spine between the bases of gnathopods 2 9
8b Without a ventral spine between the bases of gnathopods 2 12
9a
9b
10a
10b
11a
11b
12a Head without any dorsal spines, knobs, or tubercles 13
12b Head with 1 or a pair of dorsal spines, knobs, or tubercles 18
13a
13b
14a
14b
15a
15b
16a
16b
17a
17b
18a Head with a single dorsal spine or knob 19
18b Head with a pair of dorsal spines or tubercles 23
19a Dorsal spine on head an anteriorly directed, triangular projection 20
19b Dorsal projection on head a knob that is directed upward 22
20a Tubercles on dorsal surface of pereonites small or absent (if present at all, lacking on pereonite 1); gnathopod 2 of male attached near the anterior end of pereonite 2 Caprella angusta
20b Tubercles on dorsal surface of pereonites distinct, present on all pereonites; gnathopod 2 of male attached near the middle of pereonite 2 21
21a
21b
22a
22b
23a
23b
24a
24b
25a
25b
26a
26b
27a
27b
28a
28b
29a
29b
30a
30b
31a
31b
32a
32b
33a
33b
34a
34b
35a
35b



Taxonomic Levels Represented in This Key:

  Caprella angusta
  Mayerella banksia
  Tritella pilimana



Page created by Dave Cowles, 2007
Edited by: