Halicoides

Do Nascimento, Priscila S. & Serejo, Cristiana S., 2024, New findings of the family Pardaliscidae from the southwestern Atlantic: the genus Halicoides Walker, 1896, Zootaxa 5481 (5), pp. 501-519 : 517

Identification key for World Halicoides species

1. Urosomite 1 smoth or with a dorsal bump, urosomite 2 with small or vestigial dorsal teeth........................... 2

- Urosomites 1–2 dorsally smooth or with dorsal bump, lacking teeth............................................. 3

2. Gnathopod 1, carpus and propodus with sparse setae; uropod 2, peduncle with row of robust setae; dorsal tooth of urosomite 2 small but distinguishable, reaching 1/6 of urosomite 3....................... Halicoides campensis sp. nov. ( Figs. 3 , 4 )

- Gnathopod 1 ventral margin of carpus and propodus covered with setae; uropod 2, peduncle with 1 robust seta distally; dorsal tooth of urosomite 2 vestigial................................................ Halicoides tertia ( Stephensen, 1931)

3. Pereopods 3–4, merus and carpus weakly robust.......................................................4 ( Fig. 6 )

- Pereopods 3–4, merus and carpus moderately to strongly robust..........................................6 ( Fig. 3 )

4. Upper lip rounded, not incised; pereopod 5, dactylus as long as propodus; uropod 3, outer ramus 2-articulated................................................................................. Halicoides iemanja sp. nov. ( Figs. 5–7 )

- Upper lip incised; pereopod 5, dactylus shorter than propodus; uropod 3, outer ramus 1-articulated..................... 5

5. Telson cleft to the base, 98% cleft............................................ Halicoides lolo (J.L. Barnard, 1971)

- Telson cleft almost to the base, 85% cleft.............................. Halicoides nana Birstein & Vinogradov, 1960

6. Uropod 3, outer ramus 1-articulated.............................................. Halicoides latilobata Ren, 2012

- Uropod 3, outer ramus 2-articulated........................................................................7

7. Antenna 1, article 2 of peduncle with oval structure.......................................................... 8

- Antenna 1, article 2 of peduncle lacking oval structure....................................................... 9

8. Gnathopod 1, dactylus slightly convex; epimeral plate 3, posterodistal angle with a marked tooth; uropod 1, ramus subequal to peduncle; uropod 3, article 2 of outer ramus short but distinguished.................. Halicoides anomalus Walker, 1896

- Gnathopod 1, dactylus strongly convex; epimeral plate 3, posterodistal angle with a tiny denticle; uropod 1, peduncle longer than ramus; uropod 3, article 2 of outer ramus vestigial..................... Halicoides borealis Johansen & Vader, 2018

9. Gnathopod 1, carpus and propodus long and very thin, subequal in length; coxae 3–4 longer than large, almost reaching half the length of basis................................................... Halicoides indica Birstein & Vinogradov, 1964

- Gnathopod 1, carpus shorter than propodus; coxae 3–4 short, larger than long, reaching at most 1/4 the length of basis.... 10

10. Palp of mandibles, article 3 as long as article 2............................ Halicoides anacantha (K.H. Barnard, 1925)

- Palp of mandibles, article 3 at most 50% of length of article 2................................................. 11

11. Coxa 1 acutely produced.............................................................................. 12

- Coxa 1 not produced, with rounded edges................................................................. 13

12. Upper lip incised; pereopod 5, dactylus shorter than propodus....................... Halicoides walkeri ( Ledoyer, 1973)

- Upper lip rounded, not incised; pereopod 5, dactylus as long as the propodus......... Halicoides discoveryi Thurston, 1976

13. Pereopod 6, basis without poterodistal lobe; epimeral plate 3 with straight posterior margin and quadrate posteroventral corner.............................................................. Halicoides synopiae (J.L. Barnard, 1962)

- Pereopod 6, basis with poterodistal lobe reaching the end of ischium; epimeral plates 1–3 with a distinct small tooth at the posteroventral corners................................................. Halicoides tambiella (J.L. Barnard, 1961)

Figures

FIGURE 3. Halicoides campensis sp. nov., holotype, male, 5.1 mm, Campos Basin, MNRJ 31064. Maxilliped, gnathopods, and pereopods. Scale = 0.1 mm.

FIGURE 4. Halicoides campensis sp. nov., paratype, male, 3.7 mm, Campos Basin, MNRJ 24655. Urosomites (dorsal), epimeron, uropods and telson. Paratype, female, 7.2 mm, Campos Basin, MNRJ 24627. Oostegites. Scale = 0.1 mm.

FIGURE 5. Halicoides iemanja sp. nov., holotype, female, 3.6 mm, Espírito Santo Basin, MNRJ 31057. Habitus, antennae, mouthparts. Paratype, male, 5.0 mm, Campos Basin, MNRJ 24607. Antenna 1. Scale = 0.1 mm.

FIGURE 6. Halicoides iemanja sp. nov., holotype, female, 3.6 mm, Espírito Santo Basin, MNRJ 31057, Sta. AMB5 D06 R2. Gnathopods and pereopods. Scale = 0.1 mm.

FIGURE 7. Halicoides iemanja sp. nov., holotype, female, 3.6 mm, Espírito Santo Basin, MNRJ 31057. Uropods, telson and epimeron. Paratype, male, 5.0 mm, Campos Basin, MNRJ 24607. Urosomites (dorsal view). Scale = 0.1 mm.