Asterocheres angelicae, Bahiana & Farias & Neves & Johnsson, 2025

Bahiana, Bruna, Farias, Amilcar, Neves, Elizabeth & Johnsson, Rodrigo, 2025, The taxonomic status of Phyllocheres Humes, 1996 and Neoasterocheres Canário et al., 2017, and three new Asterocheres Boeck, 1859 species (Siphonostomatoida, Asterocheridae) from Brazil, Zootaxa 5696 (2), pp. 205-232 : 222-227

Asterocheres angelicae sp. nov.

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( Figs. 11–13 )

Diagnosis: Asterocheres . Female antennule 20-segmented. Antenna with endopod 3-segmented, with armature formula: 0,1,2. Mandibular palp 1-segmented. Maxillule with 4 setae on each lobe. Maxilliped 5-segmented, with armature formula (0,0,0,1,1+claw).

Material examined: Holotype adult female ( UFBA 3986 ) dissected on a permanent slide . Paratype adult female ( UFBA 3987 ) preserved in ethanol. Specimens found associated with the sponge Callyspongia sp. Duchassaing & Michelotti, 1864 from a private terminal in Salvador City ( 12°58’19.7”S, 38°30’56.9”W), Bahia State, Brazil. Collected by the LABIMAR team on September 29, 2019 .

Description of a female: Body ( Fig. 11a ) measuring 446 µm long and 256 µm wide, typically cyclopiform, with oval, shield-like prosome and cylindrical urosome. Cephalosome with sinuous posterior margin. Second and third pedigerous somites with slightly curved lateral margins. Third pedigerous somite extended and covering fourth and fifth pedigerous somites, reaching genital double-somite. Prosome 322 µm long and 256 µm wide. Length:width ratio=1:0.7. Urosome ( Fig. 11b ), 4-segmented, fifth pedigerous somite 31 µm long and 89 µm wide. Genital double-somite measuring 69 µm long and 78 µm maximum width, length:width ratio=0.8:1. Two postgenital somites, both wider than long (20×48, 30×40 µm, respectively); Prosome:urosome ratio=1:0.4. Caudal rami as long as wide 16×17 µm. Length:width ratio=0.9:1 µm, armed with 6 plumose setae.

Antennule ( Fig. 11c ) 240 µm long (not including setae), 20-segmented. Length of segments in proximal to distal order: 27, 9, 8, 9, 4, 5, 6, 8, 9, 11, 16, 13, 16, 12, 16, 20, 24, 8, 14, and 5 µm long, respectively. Segmental homologies as follows: 1(I)-2, 2(II)-2, 3(III)-1, 4(IV)-2, 5(V)-2, 6(VI)-2, 7(VII)-1, 8(VIII)-1, 9(IX–XII)-6, 10(XIII)-1, 11(XIV)- 1, 12(XV)-1, 13(XVI)-2, 14(XVII)-1, 15(XVIII)-0, 16(XIX)-1, 17(XX)-2, 18(XXI)-2+aesthetasc, 19(XXII–XXV)- 4, 20(XXVI–XXVIII)-7. Aesthetasc 68 μm long.

Antenna ( Fig. 11d ) biramous, 162 µm long, including terminal claw. Small unarmed coxa 13 µm long; basis 45 µm long without ornamentation. Exopod 1-segmented, 5 µm long, with 2 apical unequally-sized setae. Endopod 3-segmented; first segment 36 µm long, with outer margin ornamented with setules; second segment triangular-shaped, 10 µm long, armed with apical seta; third segment measuring 16 µm long, with outer margin ornamented with setules, and armed with lateral seta and distal slender seta. All setae naked. Terminal claw 42 µm long.

Oral cone ( Fig. 12a ) almost reaching first leg intercoxal plate. Mandible ( Fig. 12a ) consisting of stylet 121 µm long, slightly widened in the medial portion. Mandibular palp 1-segmented, measuring 32 µm long without ornamentation, and 2 distal equal setae.

Maxillule ( Fig. 12b ) bilobed, both lobes laterally naked. Inner lobe 40 µm long, armed with 3 naked setae and a long plumose seta. Outer lobe 15 µm long, armed with 4 naked setae.

Maxilla ( Fig. 12c ) 183 µm long, comprising unarmed syncoxa 69 µm long and curved claw measuring 114 µm long, armed with seta and ornamented with row of setules distally.

Maxilliped ( Fig. 12d ) 5-segmented, 141 µm long; syncoxa 42 µm long, unarmed; basis 74 µm long, without ornamentation. Endopod 3-segmented, segments measuring 17, 8, and 25 µm long, respectively, with armature formula (0,1,1+claw). Claw measuring 57 µm long, elongated and distally curved. All setae naked.

Legs 1–4 ( Figs. 13a–d ) biramous, with 3-segmented rami. Armature formula as follows:

Coxa Basis Exopod Endopod

Leg 1 0-0 1-1 I-1; I-1; III,2,2 0-1; 0-2; 1,2,3

Leg 2 0-0 1-0 I-1; I-1; III,I,4 0-1; 0-2; 1,2,3

Leg 3 0-0 1-0 I-1; I-1; III,I,4 0-1;0-2; 1,I+1,3

Leg 4 0-0 1-0 I-1; I-1; III,I,4 0-1; 0-2; 1,I+1,2

Basis of leg 1 ( Fig. 13a ) with row of setules on inner margin. First exopodal segment of leg 1 ( Fig. 13a ) with robust spine, reaching third exopodal segment, and second exopodal segment with very small spine. Coxa of legs 2 and 4 ( Figs. 13 b-d) with row setules on outer margins. All exopodal segments ( Fig. 13a ) showing spinules on outer margins, except first exopodal segment of leg 1 which has row of setules. Legs 1 and 3 ( Figs. 13 a-c) showing spinules on second and third endopodal segments; all other endopodal segments showing setules, except naked first endopodal segment of leg 1 ( Fig. 13a ). Distal spines of third exopodal segment of legs 2 to 4 ( Figs. 13 b-d) strongly built, almost as long as proximal setae.

Leg 5 ( Fig. 13e ) free segment, 36 µm long, ornamented with setules in inner and outer margins, armed with 2 long terminal setae. All setae naked.

Adult male: Unknown.

Etymology. The species name “ angelicae ” is given in honor of Sister Joana Angélica, a conceptionist nun and martyr of the Brazilian Independence War, who died when resisting the invasion of the Convent of Lapa, and has her name included in the book of the Heroes and Heroines of the Country.

Remarks: Asterocheres angelicae sp. nov. belongs to the group of Asterocheres species with 20-segmented antennules, a feature shared with 26 congeners: A. banderaae Kim & Lee, 2023 ; A. bimbarrensis Bispo, Johnsson & Neves, 2006 ; A. crinoidicola Humes, 2000 ; A. espinosai Varela, Ortiz & Lalana, 2007 , A. eurychelatus Kim & Lee, 2024 , A. galeatus Kim, 2010 , A. halichondriae Stock, 1966 , A. maxillatus Stock, 1987 , A. neptunei Johnsson, 2001 , A. oricurvus Kim, 2010 , A. planus Kim, 2010 , A. proboscideus Stock, 1966 , A. processus Kim & Lee, 2024 , A. quadridens Kim, 2016 , A. rai Kim & Min, 2013 , A. scutellatus Kim & Lee, 2024 , A. sensilis Kim, 2010 , A. simplex Schirl, 1973 , A. siphunculus Bahia, Canário, Neves & Johnsson, 2012, A. spinosus Kim & Min, 2013 , A. stocki Nair & Pillai, 1984 , A. tenuipes Kim, 2010 , A. tetraodontis Kim, & Lee, 2024 , A. tricuspis Kim, 2010 , A. tridentatus Kim & Lee, 2024 , A. trisetatus Kim, 2010 .

Asterocheres angelicae sp. nov. can be differentiated from A. banderaae , A. eurychelatus , A. galeatus , A. halichondriae , A. oricurvus , A. planus , A. processus , A. quadridens , A. rai , A. scutellatus , A. sensilis , A. spinosus , A. tenuipes , A. tetraodontis , A. tricuspis , A. tridentatus , and A. trisetatus by having a 5-segmented maxilliped, while those species exhibit 6-segmented maxilliped ( Stock 1966b; Kim 2010; 2016; Kim & Min 2013; Kim & Lee 2023; 2024).

Oral cone reaching leg 1 intercoxal plate on the new species easily differentiates it from A. proboscideus , which has the oral cone reaching the caudal rami ( Stock 1966b; Bandera & Conradi 2013).

Asterocheres angelicae sp. nov. shows two distal setae on the antennal exopod, differing from A. crinoidicola , A. halicondriae , A. maxillatus , and A. neptunei which show three setae ( Stock 1966b; 1987; Humes 2000; Johnsson et al. 2001; Bandera & Conradi 2013).

Finally, A. angelicae sp. nov. can be easily differentiated from A. bimbarrensis , A. espinosai , A. simplex , and A. stocki by having a 1-segmented, while congeners have 2-segmented mandibular palp ( Schirl 1973; Nair & Pillai 1984; Varela 2012; Bispo et al. 2006; Varela et al. 2007)

Figures

FIGURE 11. Asterocheres angelicae sp. nov. female holotype (UFBA 3986). a, body, dorsal view; b, urosome; c, antennule; d, antenna. Scale bars: a–b = 50 µm; c–d = 20 µm.

FIGURE 12. Asterocheres angelicae sp. nov. female holotype (UFBA 3986). a, oral cone, mandible; b, maxillule; c, maxilla; d, maxilliped. Scale bars: a–d = 20 µm.

FIGURE 13. Asterocheres angelicae sp. nov. female holotype (UFBA 3986). a, leg 1; b, leg 2; c, leg 3; d, leg 4; e, leg 5. Scale bars: a–e = 20 µm.