Jassa, , Vader & Krapp, 2005

Conlan, Kathleen E., Desiderato, Andrea & Beermann, Jan, 2021, Jassa (Crustacea: Amphipoda): a new morphological and molecular assessment of the genus, Zootaxa 4939 (1), pp. 1-191 : 162-163

publication ID

https://doi.org/ 10.11646/zootaxa.4939.1.1

publication LSID

lsid:zoobank.org:pub:F33F42D0-A139-4CE3-97D7-1314C12CF86B

DOI

https://doi.org/10.5281/zenodo.6643196

persistent identifier

https://treatment.plazi.org/id/03B487DA-FF14-D9BA-C9C8-1B86FA68F97F

treatment provided by

Plazi

scientific name

Jassa
status

 

Key to the world species of Jassa View in CoL (both sexes) 6

1 Gnathopod 2, basis, at least the distal part of the anterolateral margin bearing a fringe of setae (at least some setal lengths 20–40% or more of the maximal basis width) (e.g., Figs 15 View FIGURE 15 , 28 View FIGURE 28 , 78 View FIGURE 78 , 88 View FIGURE 88 and 102 View FIGURE 102 ) (fringe alsopresent in juveniles but may be less pronouncedthanin adults...e.g., see Fig. 102 View FIGURE 102 ) ............................................................... 2

- Gnathopod 2, basis, setae short, minute or absent (setal lengths <20% of the maximal basis width) (e.g., Figs 37 View FIGURE 37 , 85 View FIGURE 85 , 95 View FIGURE 95 and 104 View FIGURE 104 )............................................................................................... 13

2 Gnathopod 2, propodus, anteroproximal margin with a row of long setae (setal length Ẑthe maximal basis width). Gnathopod 1, carpuswithoutasetaorclusterofsetaeattheanterodistaljunctionofthepropodus ( Figs 67 View FIGURE 67 and 68 View FIGURE 68 ) ... J. staudei Conlan, 1990 View in CoL

- Gnathopod 2, propodus, setae on the anteroproximal margin short or absent (setal length <65% of the maximal basis width). Gnathopod 1, carpus, seta(e) at the anterodistal junction of the propodus present or absent (may be slightly medial or lateral and aslongasthecarpusorveryshort) (e.g., Figs 15 View FIGURE 15 , 22 View FIGURE 22 , 65 View FIGURE 65 and 88–90 View FIGURE 88 View FIGURE 89 View FIGURE 90 ) ................................................3

3 Gnathopod 2, female, palmsinuous (e.g., Figs 88 View FIGURE 88 , 97 View FIGURE 97 and 102 View FIGURE 102 ).....................................................4

- Gnathopod 2, female, palmconcave (e.g., Figs 15 View FIGURE 15 , 26 View FIGURE 26 , 29 View FIGURE 29 and 65 View FIGURE 65 )..................................................6

4 Gnathopod 1, basis, anterior margin with a row of spine-like setae; carpus, anterodistal margin with a single or cluster of setae at thejunctionof thepropodus ( Figs 88–90 View FIGURE 88 View FIGURE 89 View FIGURE 90 ) ................................................. J. alonsoae Conlan, 1990 View in CoL

- Gnathopod 1, basis, anteriormarginwithoutarowof spine-likesetae ( Figs 85 View FIGURE 85 and 102 View FIGURE 102 ) ................................5

5 Gnathopod 1, carpus, anterodistal margin with a seta or cluster of setae at the anterodistal junction of the propodus (seta(e) ~40% thelengthof the carpus) ( Fig. 85 View FIGURE 85 ) ......................................................... J. myersi Conlan View in CoL , 19907

- Gnathopod 1, carpus, anterodistal margin without a seta or cluster of setae at the junction of the propodus ( Fig. 102 View FIGURE 102 ).......... .................................................................................... J. gruneri Conlan, 1990 View in CoL

6 Uropod 1, peduncular spinous process that extends ventrally from the peduncle and underlies the rami very short (±10% of the lengthof thelongest ramus) ( Fig. 65 View FIGURE 65 ) ................................................... J. borowskyae Conlan, 1990 View in CoL

- Uropod 1, peduncular spinous process that extends ventrally from the peduncle and underlies the rami at least 25% to 50% the lengthofthelongestramus (e.g., Figs 42 View FIGURE 42 , 88 View FIGURE 88 and 99 View FIGURE 99 ) ............................................................7

7 Gnathopod 1, carpus with a seta or cluster of setae at the anterodistal junction of the propodus (seta or setal cluster may be slightly lateralormedialandshortoraslongasthe carpus) (e.g., Figs 15 View FIGURE 15 , 22 View FIGURE 22 , 29 View FIGURE 29 , 31 View FIGURE 31 , 62 View FIGURE 62 and 81 View FIGURE 81 ) ................................8

- Gnathopod 1, carpuswithoutasetaorclusterofsetaeattheanterodistaljunctionofthepropodus ... J. monodon ( Heller, 1866) View in CoL

8 Gnathopod 1, carpus, seta or cluster of setae at the anterodistal junction of the propodus short (length <25% of the length of the carpus) andslightlymedialorlateral ( Figs 15 View FIGURE 15 and 31 View FIGURE 31 )............................................................9

- Gnathopod 1, carpus, seta or cluster of setae at the anterodistal junction of the propodus long (length 25–50% of the length of the carpusor longer) andslightlymedialorlateral ( Figs 22 View FIGURE 22 , 29 View FIGURE 29 , 62 View FIGURE 62 and 81 View FIGURE 81 ).............................................10

9 Telson, tip bearing a seta or setae extending between the third uropods (these setae are in addition to the usual upright setae at each lateral cusp and are visible when the uropods are pressed downwards and away from the telson). Antenna 2, thumbed males and adult females of any size without plumose setae on the posterior margin of article 5 and the flagellum (though setae may look finely pectinate). Gnathopod 2, propodus of major form thumbed male, thumb conical, tip acute, spine or spine group on the posteriormarginattheoriginof thethumbabsent (character statesdifferintheminor form) ( Figs 31–33 View FIGURE 31 View FIGURE 32 View FIGURE 33 ) ................... ..................................................................................... J. valida ( Dana, 1853) View in CoL

- Telson, tip without apical setae (though the usual upright setae at each lateral cusp are present). Antenna 2, large thumbed males and adult females, with dense plumose setae on the posterior margin of article 2 and the flagellum. Gnathopod 2, propodus of major form thumbed male, thumb wide, tip squared, spine or spine group on the posterior margin at the origin of the thumb absent (character statesdifferintheminor form) ( Figs 15–16 View FIGURE 15 View FIGURE 16 )..................................... J. marmorata Holmes, 1905 View in CoL

10 Gnathopod 2, basis and propodus, anterior marginal setae abundant and plumose ( Figs 62–63 View FIGURE 62 View FIGURE 63 ). Mandibular palp, article 2, with a fringeof setaeonthedorsalmargin ( Fig. 64 View FIGURE 64 ) ................................................. J. oclairi Conlan, 1990 View in CoL

- Gnathopod 2, basis and propodus, anterior marginal setae sparse and simple ( Figs 22 View FIGURE 22 , 28 View FIGURE 28 and 78 View FIGURE 78 ). Mandibular palp, article 2, withoutafringeofsetaeonthedorsalmargin ( Figs 27 View FIGURE 27 , 30 View FIGURE 30 and 82 View FIGURE 82 ) ................................................11

11 Telson, tip bearing apical seta or setae in addition to the usual upright seta or setae at each lateral cusp ( Fig. 28 View FIGURE 28 ).............. .................................................................................... J. morinoi Conlan, 1990 View in CoL

- Telson, tipwithoutapical setae, onlywiththeusualuprightsetaorsetaeateachlateralcusp ( Figs 22 View FIGURE 22 and 78 View FIGURE 78 ) ..............12

12 Antenna 2, large thumbed male and large adult female, peduncular article 5 and flagellum, posterior margin bearing dense plumose setae ( Figs 22 View FIGURE 22 and 23 View FIGURE 23 ). Gnathopod 2, propodus of major form male, thumb tip acute; spine or spine group on the posterior margin at the origin of the thumb absent (although present in small thumbed males) ( Figs 22 View FIGURE 22 and 23 View FIGURE 23 ). Gnathopod 1, female propodus, palm straight to shallowly concave. Gnathopod 2, female propodus, maximum width about 50% of maximum length, palmar anglenotclosetothedefining spines; spinestightly clustered ( Fig. 26 View FIGURE 26 ) ........................... J. slatteryi Conlan, 1990 View in CoL

- Antenna 2, thumbed male and large adult female, peduncular article 5 and flagellum setae not plumose (though may be microscopically pectinate) ( Fig. 81 View FIGURE 81 ). Gnathopod 2, propodus of major form male, thumb tip angled posteriorly, spine or spine group on the posterior margin at the origin of the thumb present ( Fig. 78 View FIGURE 78 ). Gnathopod 1, female propodus, palm convex. Gnathopod 2, female propodus, maximum width about 65% of maximum length, palmar angle close to the defining spines; spines sequential

6 This key is limited by incomplete knowledge of J. kimi View in CoL , J. laurieae View in CoL , J. monodon View in CoL and J. shawi View in CoL . Sufficient information for J. kimi View in CoL , J. monodon View in CoL and J. shawi View in CoL allow for their inclusion but Jassa laurieae View in CoL has been excluded because its characteristics are unknown posterior of pereon segment 4. See Table 11 View TABLE 11 and Remarks section for J. laurieae View in CoL for distinguishing character states.

7 J. myersi View in CoL appearstwiceinthekeybecausethesetalfringeontheanterolateralmarginofthebasisofgnathopod 2 canbe interpreted as being present or absent due to the sparseness of the setae on some individuals

( Fig. 81 View FIGURE 81 ) ............................................................................. J. carltoni Conlan, 1990 View in CoL

13 Uropod 1, peduncular spinous process that extends ventrally from the peduncle and underlies the rami short (<10% of the length of thelongest ramus) (e.g., Figs 65 View FIGURE 65 and 83 View FIGURE 83 ). Onlyknownfromthe Northeastern Pacific................................14

- Uropod 1, peduncular spinous process that extends ventrally from the peduncle and underlies the rami at least 25% to 50% the lengthofthelongestramus) (e.g., Figs 42 View FIGURE 42 , 88 View FIGURE 88 and 99 View FIGURE 99 ). Notknownfromthe Northeastern Pacific ........................15

14 Gnathopod 1, carpus, seta or setal cluster at the anterodistal junction of the propodus about 35% of the length of the carpus. Gnathopod 2, female propodus, palmsinuous ( Fig. 85 View FIGURE 85 ) ............................................ J. myersi Conlan, 1990 View in CoL

- Gnathopod 1, carpus, seta or setal cluster at the anterodistal junction of the propodus minute (<15% of the length of the carpus) and slightly medial. Gnathopod 2, female propodus, palm concave, palmar defining angle acute and close to the defining spines ( Fig. 83 View FIGURE 83 ) ............................................................................... J. shawi Conlan, 1990 View in CoL

15 Pereopods 5–7, anterior margin of the propodus, spines strong and spine row extending half or more of its full length, propodus expandedornotexpanded forgrasping ( Figs 92 View FIGURE 92 , 95 View FIGURE 95 and 99 View FIGURE 99 ). .....................................................16

- Pereopods 5–7, anterior margin of the propodus, spines mostly on the distal half, propodus not expanded for grasping (e.g., Figs 42 View FIGURE 42 , 48 View FIGURE 48 , 93 View FIGURE 93 and 96 View FIGURE 96 )........................................................................................18

16 Gnathopod 1, carpus, seta or setal cluster at the anterodistal junction of the propodus about 1/3 the length of the carpus and slightly lateral and medial. Body length at maturity 15–25 mm (thumbed males and females with setose brood plates) ( Fig. 99 View FIGURE 99 )........ .................................................................................... J. ingens ( Pfeffer, 1888) View in CoL

- Gnathopod 1, carpus without a seta or setal cluster at the anterodistal junction of the propodus. Body length at maturity 5–9 mm (thumbedmalesandfemaleswithsetosebroodplates) ( Figs 92 View FIGURE 92 and 95 View FIGURE 95 ) ............................................17

17 Pereopods 5–7, anterior margin of the propodus expanded proximally for grasping. Antenna 2, thumbed male, posterior margin of article 5 andflagellumdenselyclothedinplumose setae. Gnathopod 2, female, palmof thepropodussinuous ( Fig. 95 View FIGURE 95 ) ........ .................................................................................... J. fenwicki Conlan, 1990 View in CoL

- Pereopods 5–7, anterior margin of the propodus not expanded proximally for grasping. Antenna 2, thumbed male, posterior margin of article 5 and flagellum without plumose setae (though setae are minutely barbed). Gnathopod 2, female, palm of the propoduswithadistinctledgedistalof thepalmardefiningspines ( Fig. 92 View FIGURE 92 ) .......................... J. justi Conlan, 1990 View in CoL

18 Gnathopod 1, carpus with a seta or setal cluster at the anterodistal junction of the propodus (length about 25% of the carpus length) ( Fig. 93 View FIGURE 93 )............................................................................ J. thurstoni Conlan, 1990 View in CoL

- Gnathopod 1, carpus without a short seta or setal cluster at the anterodistal junction of the propodus (e.g., Figs 42–43 View FIGURE 42 View FIGURE 43 ), or if seta present, length <15% of thecarpuslength (e.g., Figs 60 View FIGURE 60 and 96 View FIGURE 96 ). ..................................................19

19 Mandibular palp, article 2 withafringeof setaeonthedorsalmargin ( Figs 47 View FIGURE 47 and 53 View FIGURE 53 ) ................................20

- Mandibular palp, article 2 withoutafringeofsetaeonthedorsalmargin ( Figs 41 View FIGURE 41 , 61 View FIGURE 61 and 98 View FIGURE 98 ) ...........................21

20 Uropod 3, inner ramus bearing 1 or 2 spines centrally in addition to the usual spine at the tip ( Fig. 42 View FIGURE 42 ). Antenna 2, large adult male and female, posterior margin of peduncular article 5 and flagellum article 1 bearing dense plumose setae ( Figs 42–43 View FIGURE 42 View FIGURE 43 ) (these absentinsmall juveniles). Gnathopod 2, female propodus, palmarangle bulbous, distantfromthedefiningspines ( Fig. 44 View FIGURE 44 ). .... .................................................................................. J. falcata ( Montagu, 1808) View in CoL

- Uropod 3, inner ramus without central spines (only the usual spine at the tip) ( Fig. 48 View FIGURE 48 ). Antenna 2, large adult male and female, posterior margin of peduncular article 5 and flagellum article 1 without plumose setae ( Fig. 48 View FIGURE 48 ) (although setae may be minutely barbed) ( Fig. 50 View FIGURE 50 ). Gnathopod 2, female propodus, palmarangle acute, close tothedefining spines ( Figs 51 View FIGURE 51 and 52 View FIGURE 52 ) ........... ................................................................................. J. herdmani ( Walker, 1893) View in CoL

21 Gnathopods 1 and 2, basis, anteriormarginbearingafringeof setaeorspines ( Fig. 104 View FIGURE 104 ) ......... J. hartmannae Conlan, 1990 View in CoL

- Gnathopods 1 and 2, basis, anterior margin without an obvious fringe of setae or spines (setae minute or restricted distally ( Figs 37 View FIGURE 37 , 60 View FIGURE 60 and 96 View FIGURE 96 ) ..........................................................................................22

22 Gnathopod 2, female, palm sinuous ( Fig. 97 View FIGURE 97 ). Gnathopod 2, propodus of the major form thumbed male, thumb short with acute tip, spineorspinegroupontheposteriormarginattheoriginof thethumb onaledge ( Fig. 96 View FIGURE 96 ). Southern Hemisphere ......... .......................................................................... J. kjetilanna Vaderand Krapp, 2005 View in CoL

- Gnathopod 2, female, palm concave ( Fig. 37 View FIGURE 37 ). Gnathopod 2, propodus of the major form thumbed male, thumb long with rounded or incised tip, spine or spine group on the posterior margin at the origin of the thumb residual or absent ( Figs 39 View FIGURE 39 and 60 View FIGURE 60 ). Northern Hemisphere ............................................................................................23

23 Antenna 2 markedly larger than antenna 1, width up to 2x the width of antenna 1 in the thumbed male. Gnathopod 2, propodus of themajorformthumbedmale, thumbtipnotincised ( Fig. 60 View FIGURE 60 ). North Pacific ............................... J. kimi View in CoL n. sp.

- Antenna 2 not markedly larger than antenna 1, width up to 1.5x the width of antenna 1 in the thumbed male. Gnathopod 2, propodusof themajorformthumbedmale, thumbtipincised ( Figs 37–39 View FIGURE 37 View FIGURE 38 View FIGURE 39 ). North Atlantic.................. J. pusilla ( Sars, 1894) View in CoL

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