Dulichiella tridentata, Choi & Kim & Kim, 2025
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publication ID |
https://doi.org/10.11646/zootaxa.5696.1.6 |
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publication LSID |
lsid:zoobank.org:pub:A13B425F-B210-4C9E-9C95-C274B8808D4C |
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DOI |
https://doi.org/10.5281/zenodo.17419293 |
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persistent identifier |
https://treatment.plazi.org/id/03C3766C-A058-FFC0-65DF-FA78FDCA2F6D |
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Plazi |
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scientific name |
Dulichiella tridentata |
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sp. nov. |
Dulichiella tridentata sp. nov.
(Korean name: Se-dol-gi-jjag-son-mel-li-ta-yeop-sae-u, new)
( Figs. 2–4 View FIGURE 2 View FIGURE 3 View FIGURE 4 )
Dulichiella sp. Kim et al., 2024; 169, fig. 13E.
Type material. Holotype, adult male, 5.8 mm, MABIK CR00259136 , South Korea: 34°19'26"N, 128°16'17"E, 16 August 2022, collected by Y.H. Kim. GoogleMaps Paratypes, adult male, 5.6 mm, DKUAMP202506 ; adult female, 3.8 mm, MABIK CR00259137 , data same as holotype. The remaining paratypes ( 49 ♂, 54 ♀, DKUAMP202507 ) in the collection of the corresponding author GoogleMaps .
Etymology. The specific name is from the Latin tres (three) and Latin dentatus (tooth), referring to the three teeth on the distolateral crown of the propodus of gnathopod 2.
Description. Holotype, adult male, MABIK CR00259136
Body ( Figs. 2A View FIGURE 2 , 3A View FIGURE 3 ) laterally compressed; Head ( Fig. 3B View FIGURE 3 ), lateral cephalic lobe subtruncate, weakly notched ventrally, with 2 setae on apicoventral margin; eye well developed, oval. Pleonite 1 – urosomite 3 ( Fig. 3C View FIGURE 3 ) with 7- 7-7-5-4-2 dorsal tooth formula, on each side accompanied by setae; epimeral plate 1 ( Fig. 3D View FIGURE 3 ), posteroventral corner slightly acute; epimeral plate 2, posteroventral and ventral margins with 2 setae; epimeral plate 3, posteroventral corner acutely produced, posterior margin slightly serrate, ventral margin with 4 robust setae.
Antenna 1 ( Fig. 3E View FIGURE 3 ) elongate, subequal to body in length; peduncular article 1 subrectangular, with 2 robust and 2 simple setae ventrally; peduncular article 2 subrectangular, slender, with groups of simple setae on both margins; peduncular article 3 short; length ratio of peduncular articles 1–3 = 1.00: 1.17: 0.28; flagellum much longer than peduncle, 33-articulate; accessory flagellum present, 4-articulate, distal article minute.
Antenna 2 ( Fig. 3F View FIGURE 3 ) length 0.82 × antenna 1; gland cone of peduncular article 2 well developed, subacute, produced distally; peduncular article 3 short, 2 simple setae posteriorly; peduncular articles 4-5 rectangular, slender, with groups of setae ventrally; length ratio of peduncular articles 3–5 = 1.00: 3.49: 3.26; flagellum more than 12- articles, each article with simple setae distally.
Upper lip ( Fig. 3G View FIGURE 3 ) distally rounded, with pubescent distally.
Lower lip ( Fig. 3H View FIGURE 3 ), inner lobes well developed, with pubescent distally; outer lobe subrounded, with row of feeble setae medially; mandibular lobes laterally produced.
Left mandible ( Fig. 3I View FIGURE 3 ), incisor with 4 blunt teeth; lacinia mobilis with 5 blunt teeth; accessory setal row of 10 setae between molar and lacinia mobilis; molar cylindrical triturative, truncate; palp missing.
Right mandible ( Fig. 3L View FIGURE 3 ), incisor with 6 blunt teeth; lacinia mobilis with 5 dentate teeth; accessory setal row of 12 setae between molar and lacinia mobilis; palp slender, 3-articulate; article 1 with 1 short seta; article 2 with marginal row of 6 simple setae; article 3 with 7 marginal and 4 apical simple setae; length ratio of articles 1–3 = 1.00: 2.67: 3.33 (drawn from paratype).
Maxilla 1 ( Fig. 3J View FIGURE 3 ), inner plate subtriangular, narrowing distally, with 1 simple and 2 plumose setae apically, medial margin with pubescence; outer plate subrectangular, with 10 setal teeth; palp biarticulate, proximal article short, with 2 distolateral simple setae; distal article slightly widening distally, with 5 simple and 7 robust setae apically.
Maxilla 2 ( Fig. 3M View FIGURE 3 ), inner plate with oblique row of setae medially and simple setae on medial and apical margins; outer plate slightly longer than inner plate, with simple setae apically (drawn from paratype).
Maxilliped ( Fig. 3K View FIGURE 3 ), inner plate subrectangular, truncate apically, with unequal simple and robust setae apically; outer plate elongate semielliptical, not reaching distal end of article 2 of palp, with 10 blunt robust setae on inner margin and with 3 plumose and 2 robust setae on distal margin; palp 4-articulate, article 1 with 2 simple setae on inner margin; article 2 subrectangular, with row of setae on inner margin; article 3 widening distally, with 5 simple setae on inner margin, 4 simple setae and pubescence on distal margin; article 4 slender, falcate; length ratio of articles 1–4 = 1.00: 3.89: 2.78: 2.51.
Gnathopod 1 ( Fig. 4A View FIGURE 4 ) subchelate, coxa subquadrate, anterior margin slightly concave, with 10 unequal simple setae ventrally, posterodistal corner slightly notched; basis subrectangular, narrowing proximally, with simple setae anteriorly and posteriorly; ischium subquadrate; carpus moderate, with 5 clusters of simple setae ventrally; propodus subovate, slightly shorter than carpus, with group of simple setae ventrally; palm oblique, with unequal setules marginally; dactylus falcate, fitting palm; length ratio of articles 2–7 = 1.00: 0.39: 0.49: 0.83: 0.72: 0.44.
Gnathopod 2 ( Fig. 4B View FIGURE 4 , large) subchelate; coxa subquadrate, width 0.64 × length, with 6 simple setae ventrally; propodus massive, distolateral crown with 3 rounded teeth, increasing in size distally; palm straight, posterodistal corner produced, blunt, upturned; dactylus stout, blunt, fit in palm; length ratio of articles 2–7 = 1.00: 0.24: 0.35: 0.12: 2.23: 1.66.
Gnathopod 2 ( Fig. 4C View FIGURE 4 , small) subchelate; merus, posteroventral corner with acute projection; carpus widening distally, subequal to propodus in length; propodus elongate-ovate, with clusters of simple setae on dorsal and ventral margins; length ratio of articles 2–7 = 1.00: 0.29: 0.42: 0.79: 0.79: 0.21.
Pereopod 3 ( Fig. 4D View FIGURE 4 ), coxa subquadrate, width 0.78 × length; basis slender, with simple setae on posterior margin; merus subrectangular, slightly produced anterodistally, with 3 simple setae on anterior margin, 1 robust seta on anterodistal corner, and 4 unequal simple setae on posterior margin; carpus and propodus subrectangular, slender; dactylus falcate, with 1 penicillate seta on anterior margin, and 1 distinct accessory tooth on nail; length ratio of articles 2–7 = 1.00: 0.18: 0.61: 0.47: 0.56: 0.21.
Pereopod 4 ( Fig. 4E View FIGURE 4 ) similar to pereopod 3 except coxa more quadrate, basis to propodus shorter than those of pereopod 3; length ratio of from basis to dactylus = 1.00: 0.20: 0.56: 0.32: 0.54: 0.18.
Pereopod 5 ( Fig. 4F View FIGURE 4 ), coxa bilobated, anterior lobe protruding roundly downward, with 1 robust seta posteroventrally; basis subrectangular, posterior margin straight, both margins with row of robust setae; merus subrectangular, slightly expanded posteriorly, anterior margin with groups of simple setae, posterior margin with 3 robust setae; propodus subrectangular, slender, posterior margin with groups of robust setae; dactylus falcate, with 1 penicillate seta on anterior margin, and 1 accessory tooth on nail; length ratio of articles 2–7 = 1.00: 0.21: 0.79:0.60: 0.82: 0.27.
Pereopod 6 ( Fig. 4G View FIGURE 4 ) similar to pereopod 5, but basis to propodus longer than those of pereopod 5; length ratio of articles 2–7 = 1.00: 0.23: 0.90: 0.71: 0.99: 0.29.
Pereopod 7 ( Fig. 4H View FIGURE 4 ) similar to pereopod 6, but coxa unilobate, rounded ventrally; length ratio of articles 2–7 = 1.00: 0.28: 0.84: 0.73: 1.00: 0.28.
Uropod 1 ( Fig. 4I View FIGURE 4 ), peduncle subrectangular, slightly shorter than outer ramus, with a row of 5 dorsolateral, 5 dorsomedial, 1 distoventral, and 2 apicolateral robust setae; outer ramus slightly shorter than inner ramus, with 6 dorsal and 4 apical robust setae; inner ramus with 2 rows of dorsal robust setae and 4 apical robust setae.
Uropod 2 ( Fig. 4J View FIGURE 4 ), peduncle proximal portion broken, subrectangular; both rami with 4 dorsal and 3 apical robust setae, and row of setules dorsally; outer ramus slightly shorter than inner ramus.
Uropod 3 ( Fig. 4K View FIGURE 4 ), peduncle slender, subrectangular, 0.60 × outer ramus, with 3 dorsomedial, 1 dorsolateral, and 2 ventrodistal robust setae; outer ramus biarticulate, proximal article elongate, with clusters of simple setae on both margins; distal article short, 0.12 × proximal one; inner ramus minute, scale-like, with 1 robust seta subapically.
Telson ( Fig. 4L View FIGURE 4 ) laminar, completely cleft, length 1.10 × width, each lobe with 3 lateral robust setae.
Paratype, adult female, MABIK CR00259137 .
Body ( Figs. 2B View FIGURE 2 , 4M View FIGURE 4 ) about 3.8 mm long, similar to male, but, both gnathopod 2 have a similar shape.
Gnathopod 1 ( Fig. 4N View FIGURE 4 ) similar to that of male except propodus more ovate; length ratio of articles 2–7 = 1.00: 0.38: 0.42: 0.88: 0.83: 0.38.
Gnathopod 2 ( Fig. 4O View FIGURE 4 ) unlike the male, whose gnathopod 2 is asymmetrical, both propodi of gnathopod 2 similar in shape; length ratio of articles 2–7 = 1.00: 0.29: 0.36: 0.89: 0.93: 0.32.
Remarks
According to Lowry and Springthorpe (2007) and Cummings et al. (2021), the genus Dulichiella is distinguished from other genera by two key characters: 1) the number of teeth on the distolateral crown on propodus of gnathopod 2; and 2) the dorsal tooth formula from pleonite 1 to urosomite 3.The new species, Dulichiella tridentata sp. nov., characterized by a laterodistal crown with three teeth on gnathopod 2, is morphologically similar to seven species: D. anisochir (Krøyer, 1845) from Brazilian waters, D. australis (Haswell, 1879) from Australian waters, D. beluu Myers, 2016 , from Palau, D. ohau Lowry & Springthorpe, 2007 from Hawaii, D. spinosa Stout, 1912 from USA, D. terminos Lowry & Springthorpe, 2007 from Mexico, and D. tulear Lowry & Springthorpe, 2007 from Madagascar. The new species, however, is obviously distinguished from these congeners by the characteristics summarized in Table 1 View TABLE 1 and the following combination of features: 1) pleon 1 to urosomite 3, dorsal teeth formula 7-7-7-5-4-2 ( vs. 7-7-7-5-6- 2 in D. beluu , D. ohau , and D. tulear , 9-9-7-5-4- 2 in D. spinosa , 9-9-9-5-4- 2 in D. terminus , and 9-9-9-5- 6- 2 in D. anisochir ); 2) epimeral plate 3 with serrate posterior margin ( vs. smooth in D. australis , D. beluu , D. ohau , and D. spinosa ); 3) cephalic lobe with two setae ( vs. without setae in D. terminus and D. tulear , with one seta in D. anisochir , D. beluu , and D. spinosa ); 4) antenna 1, peduncular article 1 ventral margin with two setae ( vs. three setae in D. anisochir , D. beluu , D. spinosa , and D. terminus , with four setae in D. australis ); 5) antenna 1, accessory flagellum 4-articulate ( vs. 5-articulate in D. beluu , 6-articulate in D. spinosa ); 6) antenna 2, gland corn reaching the end of article 3 ( vs. not reaching in D. anisochir and D. spinosa ); 7) gnathopod 1, coxa anterior margin concave ( vs. straight in D. australis , D. beluu , D. ohau , D. spinosa , and D. terminus , convex in D. tulear ); 8) gnathopod 2, palmer corner upturned ( vs. straight in D. ohau , D. spinosa , and D. tulear ); and 9) pereopods 3–7, dactyli with one accessory tooth ( vs. two accessory teeth in D. ohau ).
Furthermore, the dorsal teeth formula of pleonite 1 to urosomite 3 (7-7-7-5-4-2) also aligns D. tridentata sp. nov., with eight additional species; D. appendiculata (Say, 1818) and D. lecroyae Lowry & Springthorpe, 2007 from USA, D. australis from Australian waters, D. brunoi Cummings, araujo, andrade & Senna, 2021 from Brazilian waters, D. cuvettensi s appadoo & Myers, 2005 from Mauritius, D. fresnelii (audouin, 1826) from Egypt, D. pacifica Lowry & Springthorpe, 2005 from Solomon Islands, and D. takedai Tomikawa & Komatsu, 2012 from Japanese waters. The new species, however, is obviously distinguished from them by the characters listed in Table 1 View TABLE 1 and the following features: 1) epimeral plate 3 with serrate posterior margin ( vs. smooth in D. appendiculata , D. australis , D. brunoi , D. cuvettensis , D. fresnelii , D. lecroyae , and D. pacifica ); 2) cephalic lobe with two setae ( vs. without setae in D. brunoi , with one seta in D. appendiculata , D. lecroyae , and D. pacifica ); 3) antenna 1, peduncular article 1 ventral margin with two setae ( vs. three setae in D. appendiculata , D. cuvettensis , D. lecroyae , D. pacifica , and D. takedai , with four setae in D. australis and D. fresnelii ); 4) antenna 1, accessory flagellum 4-articulate ( vs. 5- articulate in D. brunoi ); 5) antenna 2, gland corn reaching the end of article 3 ( vs. not reaching in D. brunoi , D. fresnelii , and D. lecroyae ); 6) gnathopod 1, coxa anterior margin concave ( vs. straight in D. australis , D. brunoi , D. cuvettensis , D. lecroyae , D. pacifica , and D. takedai ); 7) gnathopod 2, laterodistal crown with three teeth (vs. four teeth in D. appendiculata , D. brunoi , D. cuvettensis , D. fresnelii , D. lecroyae , D. pacifica , and D. takedai ); and 8) pereopods 3–7, dactyli with one accessory tooth ( vs. two accessory teeth in D. appendiculata , D. cuvettensis , D. fresnelii , and D. takedai ).
To date, only one species belonging to the genus Dulichiella , D. appendiculata , has been recorded in Korea ( Kim 1991). Kim noted that the Korean specimens agreed with the descriptions of Barnard (1970), Hirayama and Kikuchi (1979) and Ledoyer (1982) except for minor variations ( Kim 1991). However, D. appendiculata s.l. as described by Kim can be distinguished from original description of D. appendiculata based on the following features (different characters of original D. appendiculata in brackets): 1) cephalic lobe with two setae on ventral margin ( vs. with one seta); 2) gnathopod 2, distolateral crown on the propodus with three teeth ( vs. with four teeth); and 3) pereopods 5–7, dactyli with one accessory tooth ( vs. two accessory teeth). These discrepancies warrant a re-examination of D. appendiculata s.l. recorded in Korea. Notably, D. tridentata sp. nov. is similar to D. appendiculata s.l. as described by Kim in the following features: 1) gnathopod 2, distolateral crown on the propodus with three teeth; and 2) pereopods 3–7, dactyli with one accessory tooth. However, Dulichiella appendiculata s.l. as described by Kim can be also distinguished from D. tridentata sp. nov. in the following features: 1) antenna 1 elongate, longer than antenna 2 (× 1.37) and flagellum 33-articulate ( vs. moderate, subequal to antenna 2 (× 1.02), flagellum 20-articulate); 2) epimeral plate 1 with a slightly notched posteroventral corner ( vs. unnotched); and 3) telson lacking dorsal robust seta ( vs. with one dorsal robust seta). Currently, the specimen supporting the record of D. appendiculata s.l. in Korea is uncertain where abouts, making it impossible to directly verify the specimen. Additionally, the description provided is very brief. Therefore, we cannot clearly define the relationship between the new species, D. tridentata sp. nov., and the recorded D. appendiculata s.l. in Korea. Until more definitive research based on specimens is conducted, we consider the two species to be separate.
Distribution. Korea (Southern Sea).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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