Ampeliscidae, Costa, 1857

Marinho, Rômulo & Souza-Filho, Jesser F., 2025, A new species of Ampelisca Krøyer, 1842 (Amphipoda, Ampeliscidae) from Potiguar Basin, Brazil, Zootaxa 5618 (1), pp. 119-128 : 126-127

Key to the species of the family Ampeliscidae recorded from the Brazilian coast (modified from Valerio-Berardo 2008, Souza-Filho et al., 2009)

1a. Pereopod 7 anterior margin of basal lobe lacking setae near its junction with merus, dacylyl not spine like.............. 2

1b. Pereopod 7 anterior margin of basal lobe bearing setae near junction with merus, dactlyl spine like................... 24

2a. Head with a rostrum or with a short projection on anterodorsal corner............................................ 3

2b. Head without rostrum, anterodistal corner transverse......................................................... 5

3a. Anterodorsal corner reaching end of peduncle article 1 of antenna 1; uropod 3 rami broad... A. paria Barnard & Agard, 1986

3b. Head with a short projection on anterodorsal corner, not reaching the middle of peduncle article 1 of antenna 1; uropod 3 rami lanceloate........................................................................................... 4

4a. Corneal lenses present; uropod 2 with one long apical robust seta on outer ramus; telson distal margin pointed........................................................................................ A. anae Valério-Berardo, 2008

4b. Corneal lenses absent; uropod 2 without apical seta on outer ramus; telson distal margin blunt................................................................................................... A. minuta Valério-Berardo, 2008

5a. Head strongly narrow anteriorly, anteroventral margin paralell to anterodorsal margin............................... 6

5b. Head slightly narrow anteriorly, ventral margin oblique...................................................... 11

6a. Posteroventral corner of epimeral plate 3 without spine....................................................... 7

6b. Posteroventral corner of epimeral plate 3 with a spine........................................................ 8

7a. Antenna 1 shorter than antenna 2 peduncle; uropod 3 rami very broad, distal margin rounded; urosomite 1 dorsal carina pointed................................................... A. flabellicaudata Valério-Berardo & Wakabara, 2006

7b. Antenna 1 subequal in length to antenna 2 peduncle; uropod 3 rami foliaceous; urosomite 1 dorsal carina saddle-shaped.......................................................................... A. meridionalis Valério-Berardo, 2007

8a. Pereopod 7 ventral margin of basis rounded; urosomite 1 produced into an acute process; posterior margin of epimeral plate 3 bisinuate............................................................................................ 9

8b. Pereopod 7 ventral margin of basis nearly transverse (in larger specimens can be rounded); urosomite 1 dorsal carina produced into a rounded process; posterior margin of epimeral plate 3 not bisinuate........................................ 10

9a. Coxa 1 with a deep notch “V” shaped; pereopod 7 basis with posterior margin with a row of robust setae............................................................................................ A. brevisimulata Barnard, 1954

9b. Coxa 1 with a deep notch “U” shaped; pereopod 7 basis with posterior margin with a row of slender setae............................................................................................... A. soleata Oliveira, 1954

10a. Antenna 1 about 1/3 body length; maxilliped inner plate with 2 chisel-shaped robust setae; pereopod 7 basis with posterior margin reaching to end of merus; telson lobes notched at tip................ A. pesudobicarinata Souza-Filho et al., 2009

10b. Antenna 1 about the length of the body; maxilliped inner plate with 3 chisel-shaped robust setae; pereopod 7 basis with posterior margin reaching midlength of merus; telson lobes not notched at tip.................. A. cristata Holmes, 1908 *

11a. Uropod 3 with broad rami............................................................................. 12

11b. Uropod 3 with lanceolate rami......................................................................... 13

12a. Antenna 2 subequal to body length; pereopod 7 propodus stout (length 1.5X breadth), dactylus longer than propodus............................................................................ A. angraensis Souza-Filho et al., 2009

12b. Antenna 2 longer than body length; pereopod 7 slender (length 2X breadth), dactylus shorter than propodus..................................................................................... A. wakabarae Valério-Berardo, 2008

13a. Pereopod 7 merus posterior margin strongly lobed, lobe extending to distal end of carpus or more.................... 14

13b. Pereopod 7 merus posterior margin weakly lobed, lobe not extending the middle of carpus.......................... 18

14a. Epimeral plate 3 posteroventral corner without spine; telson distal margin blunt................................................................................................... A. moreirai Valério-Berardo & Wakabara, 2006

14b. Epimeral plate 3 posteroventral corner with 1 spine; telson distal margin pointed.................................. 15

15a. Pereopod 7 propodus longer than twice dactylus length; uropod 2 both rami with 1 long apical robust seta.................................................................................... A. longipropoda Valério-Berardo, 2007

15b. Pereopod 7 propodus shorter than twice dactylus length; uropod 2 outer ramus with 1 long apical robust seta............ 16

16a. Antenna 2 subequal to body length; pereopod 7 basis posterior margin smooth................ A. pugetica Stimpson, 1864

16b. Antenna 2 longer than body length; pereopod 7 basis posterior margin crenulated................................. 17

17a. Pereopod 7 propodus twice longer as carpus; Epimeral plate 3 posteroventral corner with spine............................................................................................. A. rocasensis Souza-Filho et al., 2009

17b. Pereopod 7 propodus 1.5 X longer than carpus; epimeral plate 3 posteroventral corner quadrate.................................................................................................. A. youngi Valério-Berardo, 2007

18a. Pereopod 7 carpus without a notch on anterior margin....................................................... 19

18b. Pereopod 7 carpus with a notch on anterior margin.......................................................... 21

19a. Antenna 1 overreaching peduncle of antenna 2; gnathopod 1 coxa with a slit on posteroventral corner.... A. milenae sp. nov.

19b. Antenna 1 shorter than peduncle of antenna 2; gnathopod 1 coxa without a notch on posteroventral corner............. 20

20a. Antenna 1 reaching middle of peduncular article 5 of antenna 2; urosomite 1 dorsal carina raised into a lens-shaped process; inner ramus of uropod 3 distally uncinate................................................ A. romigi Barnard, 1954

20b. Antenna 1 reaching end of peduncular article 4 of antenna 2; urosomite 1 dorsal carina rounded and without lens-shaped process; inner ramus of uropod 3 not distally uncinate...................... A. subtropicalis Valério-Berardo et al., 2005

21a. Antenna 1 subequal in length to peduncle of antenna 2; uropod 3 outer margin of inner ramus nacked, outer ramus notched at tip................................................................. A. rodriguesi Valério-Berardo et al., 2005

21b. Antenna 1 shorter than peduncle of antenna 2; uropod 3 outer margin of inner ramus with 1 stout robust seta or more, outer ramus not notched at tip............................................................................... 22

22a. Uropod 3 inner ramus with only 1 robust seta on outer margin...................... A. campensis Valério-Berardo, 2008

22b. Uropod 3 inner ramus with more than 3 robust setae on outer margin........................................... 23

23a. Uropod 1 peduncle with 1 large robust seta on distal margin and outer ramus lacking marginal robust setae; pereopod 7 merus weakly poduced posterodistally............................................. A. cristianae Souza-Filho et al., 2009

23b. Uropod 1 peduncle without 1 large robust seta on distal margin and outer ramus with marginal robust setae; pereopod 7 merus not produced posterodistally.................................................. A. burkei Barnard & Thomas, 1989

24a. Posteroventral lobe of basis on pereopod 7 expanded ventrally, posterior margin oblique................................................................................................ Byblis bjornbergae Valério-Berardo, 2008

24b. Posteroventral lobe of basis on pereopod 7 either rectangular or not expanding ventrally, posterior margin parallel.............................................................................. Haploops meloi Valério-Berardo, 2008

*According to Souza-Filho et al. (2009) the occurrence of A. cristata in Brazilian waters needs confirmation.