Halicoides campensis, Do Nascimento & Serejo, 2024

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 : 507-512

Halicoides campensis sp. nov.

( Figures 2–4 )

Material examined. Holotype: Male, length 5.1 mm, MNRJ 31064 , Sta. HAB17 D04 R3 (dissected).

Paratypes: 1 male, length 3.7 mm, MNRJ 24655 , Sta. HAB17 C02 R3 (dissected) ; 1 female, length 7.2 mm, MNRJ 24627 , Sta. HAB11 E04 R2 (dissected) ; 1 male, MNRJ 24608 , Sta. HAB9 H06 R3 (2-5) ; 1 male, MNRJ 24609 , Sta. HAB9 I07 R3 (0-2) ; 1 female, MNRJ 24610 , Sta. HAB09 CANG7 R3 (0-2) ; 1 female, MNRJ 24612 , Sta. HAB10 I12 R3 (0-2) ; 1 male, 1 juvenile, MNRJ 24613 , Sta. HAB11 C02 R1 ; 1 male, 1 female, 2 juveniles, MNRJ 24614 , Sta. HAB11 C02 R2 ; 1 juvenile, MNRJ 24615 , Sta. HAB11 C02 R3 ; 1 juvenile, MNRJ 24616 , Sta. HAB11 C03 R2 ; 1 female, MNRJ 24617 , Sta. HAB11 C03 R3 ; 1 male, MNRJ 24618 , Sta. HAB11 D01 R3 ; 3 juveniles, MNRJ 24619 , Sta. HAB11 D02 R1 ; 2 males, 1 female, 4 juveniles, MNRJ 24620 , Sta. HAB11 D02 R2 ; 1 male, 1 juvenile, MNRJ 24621 , Sta. HAB11 D02 R3 ; 1 male, 2 females, 1 juvenile, MNRJ 24622 , Sta. HAB11 E02 R1 ; 2 females, 2 juveniles, MNRJ 24623 , Sta. HAB11 E02 R2 ; 2 females, 2 juveniles, MNRJ 24624 , Sta. HAB11 E02 R3 ; 1 male, MNRJ 24625 , Sta. HAB11 E03 R1 ; 1 female, MNRJ 24626 , Sta. HAB11 E04 R1 ; 1 male, 1 female, MNRJ 24628 , Sta. HAB 11 E04 R3 ; 2 females, 4 juveniles, MNRJ 24632 , Sta. HAB11 F02 R1 ; 1 male, 4 females, 6 juveniles, MNRJ 246333 , Sta. HAB11 F02 R2 ; 1 male, 2 females, 7 juveniles, MNRJ 24634 , Sta. HAB11 F02 R3 ; 2 juveniles, MNRJ 24629 , Sta. HAB11 F03 R1 ; 1 male, 1 juvenile, MNRJ 24630 , Sta. HAB 11 F04 R2 ; 1 female, MNRJ 24631 , Sta. HAB11 G03 R2 ; 1 female, MNRJ 24635 , Sta. HAB13 A03 R2 ; 2 juveniles, MNRJ 24636 , Sta. HAB13 D03 R1 ; 1 female, 1 juvenile, MNRJ 24637 , Sta. HAB13 D03 R2 ; 1 male, 1 juvenile, MNRJ 24638 , Sta. HAB13 D03 R3 ; 1 female, MNRJ 24639 , Sta. HAB13 FOZ09 R1 (0-10) ; 1 female, MNRJ 24640 , Sta. HAB13 FOZ23 R3 (0-10) ; 2 females, 1 juvenile, MNRJ 24641 , Sta. HAB13 FOZ33 R1 (0-10) ; 2 females, 2 juveniles, MNRJ 24642 , Sta. HAB13 FOZ33 R3 (0-10) ; 1 male, 1 female, MNRJ 24643 , Sta. HAB13 FOZ43 R2 (0-10) ; 2 males, 1 female, 2 juveniles, MNRJ 24644 , Sta. HAB13 FOZ43 R3 (0-10) ; 1 female, 1 juvenile, MNRJ 24646 , Sta. HAB16 C05 R3 ; 1 juvenile, MNRJ 24647 , Sta. HAB16 D03 R1 ; 2 males, MNRJ 24648 , Sta. HAB16 D03 R2 ; 2 males, 1 juvenile, MNRJ 24649 , Sta. HAB16 D03 R3 ; 2 juveniles, MNRJ 24651 , Sta. HAB16 E05 R2 ; 1 female, MNRJ 24652 , Sta. HAB16 F04 R1 ; 2 females, 2 juveniles, MNRJ 24653 , Sta. HAB16 F04 R2 ; 1 male, 1 female, MNRJ 24654 , Sta. HAB16 H05 R3 ; 1 male MNRJ 24656 , Sta. HAB17 D02 R3 ; 3 males, 3 females, 1 juvenile, MNRJ 24657 , Sta. HAB17 D04 R1 ; 2 males, 4 females, 1 juvenile, MNRJ 24658 , Sta. HAB17 D04 R2 ; 1 female, MNRJ 24559 , Sta. HAB17 FOZ33 R1 ; 1 male, 2 females, MNRJ 24660 , Sta. HAB17 FOZ33 R2 ; 1 female, MNRJ 24661 , Sta. HAB17 FOZ33 R3 (0-10) ; 2 females, MNRJ 24662 , Sta. HAB17 FOZ34 R3 ; 1 juvenile, MNRJ 24663 , Sta. HAB17 FOZ43 R1 ; 2 females, MNRJ 24664 , Sta. HAB17 FOZ43 R2 ; 1 juvenile, MNRJ 24665 , Sta. HAB17 FOZ43 R3 ; 1 female, MNRJ 31078 , Sta. AMB3 CAND4 R1 ; 1 female, MNRJ 31079 , Sta. AMB12 F05 R1 ; 1 male, Sta. SANSED2 E06 R1 (0-2) , MNRJ 31031 ; 1 male, Sta. SANSED2 E06 R3 (0-2) , MNRJ 31032 ; 1 male, Sta. SANSED8 F06 R2 (5-10) , MNRJ 31033 .

Etymology. In reference to this being the dominat species of all Pardaliscidae in the Campos Basin, Brazil, Southwest Atlantic Ocean. About 40% of Pardaliscidae samples examined from the Campos Basin belong to this species.

Diagnosis. Antenna 1, primary flagellum long with 30 articles; article 1 in males fused, callinophore present; short aesthetascs present both sexes, never more than 1 per article; accessory flagellum in males with fused and flattened article 1. Antenna 2, peduncle, articles 4–5 about 10x longer than wide; flagellum with at least 26 articles. Upper lip asymmetrically incised. Mandibles, 1 raker present on the right; palp article 3 about 0.7x the length of article 2. Gnathopod 2 much more setose than 1, carpus and propodus covered by setae. Pereopods 3–4, strongly setose; merus strongly robust, almost as long as wide; carpus strongly robust, suboval, about 1.5x longer than wide. Pereopod 5, dactylus as long as propodus. Pereopods 6–7, dactylus half the length of propodus. Urosomite 1 with a dorsal bump and 1 short simple seta. Urosomite 2 with 1 very short tooth, 1 simple seta longer than tooth. Uropod 2, peduncle with 1 row of robust seta; outer ramus, with 2 rows of robust setae; inner ramus, with 1 row of robust setae. Uropod 3, article 2 of outer ramus small, about 10% the length of the ramus. Telson cleft about 80% of the length.

Description. Holotype, male, 5.1 mm, MNRJ 31064. Head wider than long; cephalic lobe present, well developed, exceeding half-length of article 1 of peduncle of antenna 1; rostrum present, long, reaching the end of article 1 of peduncle of antenna 1; eyes absent. Antenna 1, peduncle very short, reaching less than half of article 4 of peduncle of antenna 2; article 1 the longest, 3x the length of the article 2, articles 2 and 3 subequal in length, article 3 shorter anteriorly; primary flagellum long, with 30 articles, distal simple setae on each one, aesthetascs present at the first 10 articles, article 1 fused, 0.7x the size of the peduncle, callinophore present; accessory flagellum with 3 articles, article 1 fused almost as long as article 1 of the primary flagellum, flattened, with 2 groups of simple setae. Antenna 2, longer than antenna 1; peduncle, article 3 very short, as long as wide, articles 4–5 subequal in length and width, about 10x longer than wide, article 4 with 3 short robust setae and some short simple setae; flagellum with at least 26 articles (broken).

Mouthparts forming a quadratiform bundle. Upper lip asymmetrically incised. Mandibles, incisor microdentate, row of setae present and molar absent on both sides; right mandible, lacinia mobilis wide, more than half the width of the incisor, microdentate, 1 raker present; left mandible, lacinia mobilis as long as wide, microdentate; palp, 3– articulated on both sides, articles 1–3 with simple setae; article 1 short, article 2 about 3x longer than article 1; article 3 about 0.7x the length of article 2, with 2 long simple setae apically. Lower lip, inner lobes coalesced. Maxilla 1, inner plate reduced, with 1 long simple seta apically; outer plate with 1 subapical plumose seta and 7 apical robust setae, 3 of them with a subapical tooth; palp 2-articulated, article 2 not expanded distally, with 4 subapical simple setae and 6 apical robust setae. Maxilla 2, slender plates, about 3x longer than wide, plates subequal in length; inner plate with 8 simple setae on the inner margin, 1 simple seta and 1 plumose seta apically; outer plate with 2 simple setae and 1 plumose seta apically. Maxilliped, inner plate reduced, with 2 apical simple setae; outer plate, reaching article 2 of the palp, with 3 facial simple setae, 7 robust setae on the inner margin and 2 robust setae apically; palp 4-articulated, article 1 with 1 simple seta on the inner margin, article 2 with 3 plumose setae on the inner margin, article 3 with a few simple setae in the distal half, article 4 smooth, without tooth, and 1 small simple seta.

Coxae 1–7 short, wider than long; coxa 1 projected anteriorly; coxae 2–3 suquadrate; coxa 4 projected anteriorly; coxa 5 with anterior projection well developed; coxa 6 with posterior projection; coxa 7 the narrowest, projected posteriorly over epimeron 1. Gnathopod 1 slender, basis and ischium with 1 simple seta on posterodistal angle of each one; merus with 2 simple setae; carpus, 2x longer than wide, shorter than propodus, with 4 simple setae; propodus 3x longer than wide, with a few simple setae; palm absent (simple), dactylus smooth with 2 short simple setae. Gnathopod 2 slender, a little bit more robust and much more setose than gnathopod 1; basis with 3 simple setae on anterior margin; ischium with 2 long plumose setae and 2 simple setae; merus with 4 simple setae; carpus 1.8x longer than wide, shorter than propodus, ventral margin covered by long simple setae; propodus 3x longer than wide, covered by simples setae and 8 plumose setae with setules on only one side; dactylus smooth with 4 short simple setae.

Pereopod 3, basis and ischium with simple setae distally; merus strongly robust, almost as long as wide with simple setae on ventral margin; carpus strongly robust, suboval, about 1.5x longer than wide, ventral margin covered by simple setae and two types of plumose setae, with long and short setules; propodus subequal in length to carpus, narrower, with simple setae mostly on ventral margin; dactylus shorter than propodus, simple, not subdivided. Pereopod 4 similar to 3 in shape and size; basis a little more setose and carpus a little less setose, without plumose setae with short setules. Pereopod 5 about 1.5x longer than pereopod 4; basis 1.8x longer than wide, with a weak posterior lobe, anterior margin with robust setae with apical seta; ischium, anteroventral angle with 1 group of robust setae with apical seta; merus on anterior margin with groups of robust setae with apical seta, carpus on posterior margin, and propodus on both margins; propodus 10x longer than wide; dactylus as long as propodus. Pereopod 6 about 1.5x longer than pereopod 5, more setose, articles with setae on both margins; basis, with posterior lobe; merus with plumose setae; propodus 10x longer than wide; dactylus half length of the propodus. Pereopod 7 a little shorter than pereopod 6; basis broadly rounded, 1.5x longer than wide with posterior lobe reaching the end of ischium; propodus 10x longer than wide; dactylus half length of the propodus.

Epimeron 1–3 subquadrate, without tooth on posteroventral angle; epimeron 1–2 naked, epimeron 3 with 2 simple setae ventrally. Pleopods well developed, basal articles of ramus not fused, about 12 articles, very setose.

Urosomite 1 with a dorsal bump and 1 short simple seta. Urosomite 2 with 1 very short tooth, 1 simple seta longer than tooth. Uropod 1, peduncle subequal to ramus in length, 1 robust seta on inner margin and row of 5 robust setae on outer margin, posteroventral tooth present; biramus, ramus subequal in length, apically rounded; outer ramus with 5 dorsal robust setae and 4 apical robust setae; inner ramus with 2 dorsal robust setae and 4 apical robust setae. Uropod 2, peduncle subequal to ramus in length, 2 robust setae on inner margin and row of 6 robust setae on outer margin, posteroventral tooth present; biramus, apically rounded, outer ramus longer than inner; outer ramus, dorsal margin with 2 rows of robust setae (3+4) and 4 apical robust setae; inner ramus with row of 4 dorsal robust setae and 3 apical robust setae. Uropod 3, peduncle short, ramus 2x the length of the peduncle, peduncle with 1 simple and 1 robust seta; biramus, lanceolate, more than half of inner margin of the both ramus covered by plumose setae; outer ramus 2-articulated, article 2 about 10% the length of the ramus, with 1 very small simple seta apically. Telson 2x longer than wide, cleft about 80% of the length, each lobe with 1 pair of subequal cusps with 1 very small simple seta apically.

Females: The sexual dimorphism can be observed mainly in antenna 1. In females, the articles of primary and accessory flagellum of antenna 1 are not fused, and the callynophores are absent. This dimorphism is typical of some pardaliscid genera. Females have long and thin oostegites from pereopods 3 to 5.

Type locality. Sta. HAB17 D04 R3 , Campos Basin (22°23’22.23’’S 40°34’59.11’’W), 110 m.

General Distribution. Campos Basin , Santos Basin and Espírito Santo Basin (19º–24º S), Brazil, Southwest Atlantic Ocean, depth range from 29 to 3084 m .

Remarks. Compared with all 13 Halicoides species, H. campensis sp. nov. is closer to H. tertia in presenting a very small dorsal tooth on urosomite 2. In addition, they share the following characters: long antennae, with primary flagellum exceeding 25 articles; gnathopod 2 much more setose than gnathopod 1, with ventral margin of carpus and propodus covered with setae; pereopods 3–4, merus and carpus strongly robust and very setose. Halicoides campensis differs from H. tertia (characters in parentheses) by: antenna 2, peduncle, articles 4–5 longer, 10x longer than wide (5x longer than wide); gnathopod 1 with sparse setae (much of the ventral margin covered with setae); gnathopod 2, carpus dorsal margin naked (with about 10 long simple setae); uropod 2, peduncle with row of robust setae (with 1 distal robust setae); telson cleft about 80% (cleft about 95%).

The new species differs from all other species by the very small tooth on urosomite 2. In addition, it differs from Halicoides iemanja sp. nov., H. lolo and H. nana by the merus and carpus of pereopods 3–4 strongly robust (versus weakly robust). Halicoides anacantha and H. latilobata have the intermediate condition of expansion in the merus and carpus of pereopods 3–4.

Figures

FIGURE 2. Halicoides campensis sp. nov., holotype, male, 5.1 mm, Campos Basin, MNRJ 31064. Habitus, head (dorsal), antennae, mouthparts. Paratype, female, 7.2 mm, Campos Basin, MNRJ 24627. Antenna 1. Scale = 0.1 mm.

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.