Scottocheres jungi, Lee, 2025
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publication ID |
https://doi.org/10.5281/zenodo.16967319 |
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persistent identifier |
https://treatment.plazi.org/id/382A6976-BA6E-7154-FCE5-3A182CFF283D |
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treatment provided by |
Felipe |
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scientific name |
Scottocheres jungi |
| status |
sp. nov. |
Scottocheres jungi View in CoL n. sp. ( Figs. 12 View Fig , 13 View Fig )
https://zoobank.org/urn:lsid:zoobank.org:act:B6E15D6C-
DE19-4CA2-AC7B-7C1085A0562F
Type material. Holotype (intact ♀; HNIBR IV2386), intact paratypes (2 ♀♀; HNIBR IV2387), and dissected paratypes (1 ♀, 1 ♂) from mixed species of sponges, Chuja Island (33°47 ʹ 513.6 ʺ N, 126°19 ʹ 21.9 ʺ E), SCUBA, at a depth of 24 m, SCUBA, collected by Tae Won Jung, on 22 June 2022. The holotype and intact paratypes have been deposited in the Honam National Institute of Biological Resources ( HNIBR), Mokpo. The dissected paratypes are retained in the colletion of I.-H. Kim.
Etymology. The species is named in tribute to Dr. Tae Won Jung, who collected these specimens.
Female. Body ( Fig. 12A View Fig ) narrow. Body length 927 μm in dissected and figured specimen. Prosome 606 μm long, with thin exoskeleton. Cephalothorax 358 × 321 μm, sub-circular. First 3 prosomal somites separated from one another by broad arthrodial membranes. Second to fourth pedigerous somites 276, 264, and 200 μm wide, respectively. Urosome ( Fig. 12B View Fig ) 4-segmented. fifth pedigerous somite 114 μm wide, with angular posterolateral corners. Genital double-somite broad, 160 × 150 μm, with convex lateral margins, dentiform angle in middle of lateral margin, followed by weak subsidiary angle; genital apertures positioned dorsally in middle of double-somite length. First free abdominal somite 42 × 71 μm, with convex lateral margins. Anal somite 45 × 59 μm, with minute spinules along posteroventral margin. Caudal ramus ( Fig. 12C View Fig ) 1.25 times longer than wide (30 × 24 μm), with 6 setae and row of minute spinule along posteroventral margin; seta VII tipped on tubercle.
Rostrum absent. Antennule ( Fig. 12D View Fig ) 247 μm long, 17-segmented; armature formula 1, 2, 3, 2, 2, 2, 2, 5, 2, 2, 1, 2, 1, 1, 1, 1 + aesthetasc, and 13; first segment with several spinules on anterior margin; tenth to sixteenth segments bearing transverse row of minute spinules on posterior side near their distal margin; all setae small and naked. Antenna ( Fig. 12E View Fig ) with short, unarmed coxa; basis 63 μm long, with row of minute spinules subdistally; exopodal segment 14 × 7 μm, with inflated distal half and 3 naked setae (2 subdistal and 1 distal); endopod 2-segmented; first endopodal segment 37 × 16 μm, unarmed but with row of spinules on outer margin; second endopodal segment 19 × 7 μm, with 3 small, spiniform setae (1 proximal and 2 subdistal), few setules at outer subdistal region, and spiniform terminal claw of 58 μm long.
Oral siphon ( Fig. 12F View Fig ) consisting of slightly inflated proximal part and thin distal part, reaching insertions of legs 3. Mandible ( Fig. 12G View Fig ) represented by thin stylet, lacking palp. Maxillule ( Fig. 12H View Fig ) bilobed; outer lobe small, 15 μm long, bearing 2 naked setae (40 and 24 μm long, respectively); inner lobe 41 μm long, with spinulose, inflated inner margin, tipped with 3 setae (127, 120, and 60 μm long, respectively, from inner to outer). Maxilla ( Fig. 12I View Fig ) slender; proximal segment 95 μm long; distal segment slender, claw-like, divided by articulation-like annulation into proximal (89 μm long) and distal (60 μm long) parts. Maxilliped ( Fig. 12J View Fig ) consisting of syncoxa, basis, and 3-segmented endopod; armature formula 1, 0, 2, 1, and 1 + claw; minute spinules present on outer distal region of syncoxa and on proximal half of outer and inner margins of basis; third endopodal segment and terminal claw 36 and 59 μm long, respectively.
Legs 1 ( Fig. 13A View Fig ), 2 ( Fig. 13B View Fig ), 3, and 4 ( Fig. 13D View Fig ) with 2-segmented protopod and 3-segmented rami; inner coxal seta absent in leg 1, but present in legs 2-4; outer seta on basis small, naked. Inner distal spine on basis of leg 1 shorter than first endopodal segment, 18 μm long, spinulose. Leg 3 similar to leg 2, except bearing 1 spine plus 5 setae on third endopodal segment ( Fig. 13C View Fig ). Inner distal process of third endopodal segment of legs 2-4 spinulose. Distal spine on third exopodal and endopodal segments of leg 4 inflated. Armature formula for legs 1-4 as follows:
Coxa Basis Exopod Endopod
Leg 1 0-0 1-I I-1; I-1; III, 2, 2 0-1; 0-1; 1, 2, 3 Leg 2 0-1 1-0 I-1; I-1; II, I, 4 0-1; 0-2; 1, 2, 3 Leg 3 0-1 1-0 I-1; I-1; II, I, 4 0-1; 0-2; 1, 1 + I, 3 Leg 4 0-1 1-0 I-1; I-1; II, I, 3 0-1; 0-2; 1, I, 2
Leg 5 ( Fig. 13E View Fig ) consisting of protopod and exopod; protopod 45 × 63 μm, broad, plate-like, articulated from somite, armed with 1 naked outer distal seta and rudimentary, spinule-like inner distal seta, and ornamented with 1 row of minute spinules on outer part of distal margin and proximal part of inner margin; exopodal segment 1.43 times longer than wide (40 × 28 μm), bearing 3 subequal, naked setae on oblique distal margin. Leg 6 represented by 1 small seta and 1 spinule on genital operculum
Male (with damaged prosome). Urosome ( Fig. 13F View Fig ) 5-segmented. Fifth pedigerous somite 92 μm wide. Genital somite nearly quadrate, 110 × 136 μm. Three abdominal somites with convex lateral margins, 30 × 56, 30 × 47, and 37 × 53 μm, respectively. Caudal ramus 1.47 times longer than wide (28 × 19 μm).
Rostrum absent. Antennule ( Fig. 13G View Fig ) 15-segmented, with strong geniculation between thirteenth and fourteenth segments; armature formula 1, 2, 3, 2, 2, 2, 2, 5, 2 + aesthetasc, 4 + aesthetasc, 2, 2 + aesthetasc, 2, 2 + aesthetasc, and 11; some setae on tenth to fourteenth segments rodshaped or tipped with setule. Antenna as in female.
Oral siphon, mandible, maxillule, and maxilla as in female. Maxilliped ( Fig. 13H View Fig ) bearing digitiform, prominent process on inner margin of basis.
Legs 1, 2, and 4 as in female. Third endopodal segment of leg 3 ( Fig. 13I View Fig ) with distally bifurcate, elongated process on outer margin and truncate, elongated outer distal process. Leg 5 armed as in female. Leg 6 ( Fig. 13F View Fig ) represented by 2 small, naked setae on genital operculum.
Remarks. In the genus Scottocheres the armature formula of legs 1-4 varies across species. The armature formulae for leg segments of S. jungi n. sp. are (1) III, 2, 2 for the third exopodal segment of leg 1 (shared by six congeners), (2) II, I, 4 for the third exopodal segment of leg 2 (shared by five congeners), (3) II, I, 4 for the third exopodal segment of leg 3 (shared by five species), (4) 1, 1 + I, 3 for the third endopodal segment of leg 3 (shared by six congeners), (5) II, I, 3 for the third exopodal segment of leg 4 (shared by five congeners), (6) 1, I, 2 for the third endopodal segment of leg 4 (shared by eight congeners), and (7) 0-1 for the coxa of legs 2-4 (but not for the coxa of leg 1) (shared by four congeners). Two species in the genus, S. laubieri Stock, 1967 and S. mipoensis Kim, 2016 , share all eight armature formulae with S. jungi n. sp. Scottocheres mipoensis was recorded from Korea and can be excluded from further comparison with the new species due to having an 18-segmented female antennule and a 16-segmented male antennule ( Kim, 2016). Scottocheres laubieri was discovered in association with sponges in the Mediterranean ( Stock, 1967). Although S. laubieri shares the same armature formulae for legs and antennule segmentation with S. jungi n. sp., it differs from the new species in the following features: (1) the genital double-somite is narrow, approximately 1.56 times longer than wide, according to the illustration by Stock (1967) (vs. the double somite is 1.07 times longer than wide in S. jungi n. sp.), (2) the first free abdominal somite of the female is distinctly longer than wide (vs. wider than long in S. jungi n. sp.), (3) the outer lobe of the maxillule is armed with three setae (vs. two setae in S. jungi n. sp.), (4) the male antennule bears aesthetascs on proximal segments (vs. no aesthetasc on the proximal segments in S. jungi n. sp.), and (5) the outer and distal processes of the third endopodal segment of male leg 3 are not transformed (vs. the processes are modified in S. jungi n. sp.).
In Scottocheres the length-to-width of caudal ramus varies across species. In S. jungi n. sp., the ratio is 1.25, which may uniquely characterize this new species, as in the 11 species of the genus, the ratio is approximately 1 or less, or exceeds 2.
Johnsson et al. (2001) reported S. laubieri from Brazilian waters, but their material needs confirmation of the species identity due to incongruences with the original description, e.g., an inner coxal seta on leg 1, a monocuspid outer distal corner on the second endopodal segment of legs 1, 3, and 4, no outer distal seta on the protopod of leg 5, and the exopod of leg 5 where the mid-terminal seta is longer than the other two nearby setae.
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